Chapter 7 Experimental
7 Experimental
7.1 General Procedures
All manipulations of metal complexes and air sensitive reagents were performed under an inert atmosphere of nitrogen either by the use of standard Schlenk and vacuum line techniques or in a nitrogen filled glove box. Solutions were transferred using double ended needles
(cannulae) and gas tight syringes. Glassware and double ended needles were oven dried at 160°C overnight.
All reagents, including 1 5 N labelled compounds, were purchased from
Sigma Aldrich Pty. Ltd., except dimethylphenylphosphine, triallylphosphine, 1,2 bis (dimethylphosphino)ethane, and
1,2 bis (diethylphosphino)ethane, which were purchased from Strem
Chemicals, Inc. and used as received.
For the purposes of air sensitive manipulations and in the preparation of metal complexes, diethyl ether, tetrahydrofuran, hexane, toluene and benzene were stored over sodium wire and distilled prior to use from sodium/benzophenone ketyl under nitrogen. Methanol was dried over and distilled from magnesium turnings. Acetone was dried over and distilled
from CaSO 4 . Dimethylformamide was dried over activated molecular sieves. Absolute ethanol, 2 methoxyethanol, 2,2 dimethoxypropane and anhydrous chloroform were used as received.
221 Chapter 7 Experimental
All bulk compressed gases were obtained from British Oxygen Company
(BOC Gases). Argon (>99.99%) and nitrogen (>99.5%) were passed through drying columns of potassium hydroxide before use. Methyl bromide (>95%), carbon monoxide (>98%) and dihydrogen (>99%) were used as supplied. Vinyl bromide was purchased from Sigma Aldrich and used as supplied.
Air sensitive NMR samples were either prepared in a nitrogen filled glove box or by transferring the solutions by double ended needles through an air tight septum seal. Deuterated solvents for NMR purposes were obtained from Merck and Cambridge Isotopes, degassed using three consecutive freeze pump thaw cycles and vacuum distilled from suitable drying agents. All deuterated solvents were distilled immediately prior to use.
1 H, 1 1 B, 1 3 C, 1 5 N and 3 1 P NMR spectra were recorded on Bruker Avance spectrometers (proton frequency = 300.13, 400.13 or 500.13 MHz). NMR
Spectra were recorded at 300 K unless otherwise stated as determined using a variable temperature unit ( ±5 K). Chemical shifts ( δ) are quoted in ppm, the downfield direction being positive. 1 H and 1 3 C chemical shifts are referenced to internal solvent resonances. 1 5 N NMR chemical shifts were referenced to external neat aniline, taken to be 56.5 ppm at 300 K
(liquid ammonia scale). 3 1 P NMR chemical shifts were referenced to external neat trimethylphosphite, taken to be at 140.85 ppm at 300 K.
222 Chapter 7 Experimental
1 1 B NMR chemical shifts were referenced to external 15% BF 3 .Et 2 O in
CDCl 3 . Variable temperature NMR spectra are uncorrected for chemical shift drift with changing temperature. Uncertainties in chemical shifts (at
298/300 K) are typically ±0.02 ppm for 1 H, ±0.1 ppm for 1 3 C and 3 1 P, and
±0.2 ppm for 1 1 B and 1 5 N. Coupling constants ( J) are given in Hz and have an uncertainty of ±0.05 Hz. For convenience, the following abbreviations are used in reporting NMR resonances: s, singlet; d, doublet; t, triplet; q, quartet; p, pentet; hex., hexet; sept., septet; dd, doublet of doublets, etc; m, multiplet; b., broad; app., apparent. The following two dimensional NMR techniques were used for the assignment of some organometallic compounds: COSY ( COrrelation Spectroscop Y),
HSQC ( Heteronuclear Single Quantum Coherence), HMQC ( Heteronuclear
Multiple Quantum Coherence), EXSY ( EX change Spectroscop Y). T 1 measurements were carried out by the inversion recovery method using standard 180° τ 90° pulse sequences.
NMR data were processed on Intel PC workstations using standard Bruker software (XWinNMR/TopSpin). Accurate chemical shift and coupling constant values of cis unsymmetrical complexes were determined via simulations carried out using the NUMARIT routines (NUMARIT algorithm as described in: J. S. Martin and A. R. Quirt, J. Magn. Reson. 5, 318
(1971), modified by Rudy Sebastian) built into SpinWORKS 2.5.4
(© 1999 2006 Kirk Marat). Phosphine labelling for unsymmetrically substituted cis complexes was kept consistent for all spectra, with a labelling scheme as shown in Figure 7.1. The phosphine position trans to
223 Chapter 7 Experimental
the coordinated chloride was labelled position A whilst the remaining
2 phosphine positions were determined via J (PP) measurements.
PC
PB Cl Ru
PA X PD
Figure 7.1 – Phosphine labelling for unsymmetrical cis complexes prepared in
this work
Electrospray ionisation (ESI) and atmospheric pressure chemical ionisation (APCI) mass spectra were recorded on a Finnigan LCQ mass spectrometer. Typical experimental conditions for an ESI experiment were: ESI spray voltage 5 kV; nitrogen sheath gas pressure 60 psi; heated capillary temperature 200 °C; full scan m/z 50 to 2000. For loop injection, the typical mobile flow phase was 50% methanol/50% water with 1% acetic acid with a flow rate of 100 microliter per minute. Matrix assisted laser desorption / ionisation – time of flight (MALDI TOF) spectra were recorded on a Micromass TOF SPEC 2E spectrometer with a 337 nm
dinitrogen UV laser, using C 6 0 /C 7 0 soot as both the matrix and as an internal calibrant ( m/z = 720 and 840, two point calibration). Ions with molecular masses greater than 720 generally required a calibration of a
+ higher order, and when available known [RuCl(P P) 2 ] (P P = dmpe, depe) ions were used along with C 6 0 /C 7 0 in a three point calibration curve. Both
224 Chapter 7 Experimental
positive and negative ions were detected in reflectron mode at 20kV. A typical sample was prepared by spotting a solution of the analyte of interest in a suitable solvent on a marked stainless steel plate in an
N 2 filled glove box, allowing the solvent to evaporate to dryness, then coating the sample with a saturated solution of C 6 0 /C 7 0 in toluene, which was also allowed to evaporate to dryness. Typical spotting volumes were ca. 4 µL. Care was taken to minimise air contact ( ca. <8 s) when transferring the sample plate from the glove box to the spectrometer vacuum chamber. Data is quoted in the form x(assignment, y) where x is the mass/charge ( m/z) ratio and y is the percentage abundance relative to the base peak. Only peaks of interest are quoted.
Infrared spectra were obtained either on a Shimadzu 8400 series FTIR spectrometer as pressed discs (KBr – hand press), or as powder samples on a Bruker IFS 66/S FT IR with MIR light source and DTGS detector operating in ATR reflection mode. Raman spectra were collected on a
Bruker IFS 66/S FRA 106/S at 1064 nm as neat solid discs. For convenience, the following abbreviations are used in reporting
IR data: w, weak; m, medium; st, strong; b, broad; sh, sharp. Collection of Raman spectra was hampered by the decomposition of most intensely coloured complexes, even at low (< 5 mW) powers. Compounds which were white to yellow gave spectra with a good signal to noise ratio, whilst compounds which were green to blue generally “burned”, occasionally giving signal, but most frequently resulting in an extremely
225 Chapter 7 Experimental
large and asymmetric baseline “hump” ranging from 3580–1500 cm − 1 with a maxima at 3216 cm − 1 .
7.2 Ligand synthesis
1 7.2.1 Trichlorophosphine sulfide, PSCl 3
Sulfur powder (49.1 g, 1.53 mol) and phosphorus trichloride (211 g,
1.53 mol) were added to a two necked round bottom flask. A reflux condenser and nitrogen line were attached and the system sparged with nitrogen. Anhydrous aluminium trichloride (2.40 g, 18.0 mmol) was added through the side arm in small portions to the cooled solution; after each addition the solution was heated to reflux, and cooled before further
addition of AlCl 3 . Upon addition of sufficient AlCl 3 ( ca. 2.5 g), a vigorous exothermic reaction occurred, producing a dark brown homogenous solution. The solution was heated at reflux for a further 30 minutes, and the resulting mixture was distilled under nitrogen (123 − 125 °C) to afford trichlorophosphine sulfide as a colourless liquid (206 g, 80%).
3 1 1 P{ H} NMR (162 MHz, diethyl ether): δ P 30.5 (1P, s)
7.2.2 Methylmagnesium iodide, MeMgI
Magnesium turnings (81.7 g, 3.36 mol) was added to a 3 L wide necked flange flask and a 5 necked flange cover was secured, to which an overhead mechanical stirrer, 1 L dropping funnel, reflux condenser and a
226 Chapter 7 Experimental
nitrogen/vacuum line were attached. The entire flask was evacuated overnight to activate the magnesium turnings. Diethyl ether (1 L) was added along with a single crystal of iodine. Methyl iodide (452 g,
3.18 mol) in diethyl ether (200 mL) was added slowly (1 mL / min) to the
Mg/ether mixture, and the mixture heated without stirring until the reaction initiated, as indicated by the fading of the iodine colour from solution. Once the reaction had commenced, the mixture was stirred, heating was ceased and the MeI addition adjusted to maintain a gentle reflux. After complete addition, the reaction mixture was a dark grey solution, with traces of excess magnesium. The mixture was allowed to stir overnight and used directly in the next step.
7.2.3 Tetramethyldiphosphine disulfide,
2 Me 2 P(=S)-P(=S)Me 2
The reaction vessel from the preparation of methylmagnesium iodide was cooled to 0 °C. Additional diethyl ether (400 mL) was added and trichlorophosphine sulfide (163 g, 0.960 mol) was added dropwise over four hours, during which a thick, white precipitate formed. The mixture was allowed to warm to room temperature with stirring and then poured carefully onto crushed ice (700 g). Once the reaction had subsided, sulfuric acid (10%, 1 L) was added with stirring and the white solid collected by filtration. The solid was washed with water (4 L) and vacuum dried overnight. The dry white solid was recrystallised from boiling absolute ethanol (4 L) to give tetramethyldiphosphine disulfide as
227 Chapter 7 Experimental
white/colourless crystalline needles. Evaporation of the filtrate and recrystallisation from boiling ethanol (1 L) produced a second crop of crystals (61.5 g, 69%).
3 1 1 P{ H} NMR (162 MHz, CDCl 3 ): δ P 35.1 (2P, s)
1 H NMR (400 MHz, CDCl 3 ): δ H 2.11 1.92 (12H, m)
3 7.2.4 Dimethylphosphine, Me 2 PH
CAUTION: Dimethylphosphine is extremely pyrophoric – handle with care.
Tetramethyldiphosphine disulfide (38.1 g, 0.204 mol), tri n butylphosphine (83.8 mL, 0.425 mol), and degassed water (4.00 mL,
0.222 mol) were combined and a one piece fractioning column/condenser cooled to −5 °C was attached to the reaction flask. The collecting vessel was held at −78 °C. Care was taken to minimise air in all vessels. The reaction mixture was slowly heated to 150 °C over three hours, at which point the reaction mixture became homogeneous and clear. The temperature of the reaction mixture was increased to 180 – 210 °C and the volatile dimethylphosphine was collected under nitrogen as it distilled ( ca. 20 °C at distillation head) from the reaction mixture, giving a colourless, malodorous, extremely air sensitive liquid (15.9 g, 63%).
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran): δ P –99.1 (1P, s)
1 1 H NMR (400 MHz, d 8 tetrahydrofuran): δ H 3.09 (1H, d, J (P H) = 192.8,
PH), 0.83 (6H, bs, P Me )
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4 7.2.5 Diphenylphosphine, Ph 2 PH
Lithium chunks (3.01 g, 0.434 mol) and triphenylphosphine (56.8 g,
0.216 mol) in tetrahydrofuran (200 mL) were stirred vigorously at 0°C for two hours, then left stirring for three days. The resulting deep red reaction mixture was poured onto ice cold degassed water (150 mL) and diethyl ether (150 mL) added. The aqueous layer was separated and extracted with diethyl ether (60 mL). The combined organic fractions were washed with degassed HCl (1M, 2 x 100 mL), followed by degassed
water (2 x 100 mL). The washed organic layer was dried over MgSO 4 , filtered and the solvent removed in vacuo . The residue was vacuum distilled (0.32 mmHg, 76 − 86 °C), to give diphenylphosphine as a malodorous colourless oil (16.4 g, 41%).
3 1 1 P{ H} NMR (162 MHz, neat): δ P −40.9 (1P, s)
1 H NMR (400 MHz, neat): δ H 7.57 (4H, m, Ar H o ), 7.38 (6H, m, Ar H m , p ),
1 5.35 (1H, d, J (P H) = 218.3, P H)
5 7.2.6 Vinylmagnesium bromide, CH 2 =CHMgBr
Vinyl bromide (11.0 mL, 156 mmol) was condensed at −78°C into an evacuated measuring cylinder fitted with a rubber septum and transferred to a pressure equalising dropping funnel along with 100 mL tetrahydrofuran. The solution was added dropwise over one hour to dried
229 Chapter 7 Experimental
magnesium turnings (4.10 g, 169 mmol) in tetrahydrofuran (100 mL), activated with a crystal of iodine. The resulting dark yellow brown solution of vinylmagnesium bromide was used directly in the preparation of trivinylphosphine.
6 7.2.7 Trivinylphosphine, P(CH=CH 2 ) 3
Trimethylphosphite (4.7 mL, 40 mmol) in tetrahydrofuran (100 mL) was added dropwise to a fresh solution of vinylmagnesium bromide
(156 mmol) in tetrahydrofuran (200 mL) over one hour. The resulting brown solution was then heated at reflux for one hour. The tetrahydrofuran and trivinylphosphine were separated from the magnesium residues by distillation and used directly in the preparations
2 2 of P P 3 and P P’ 3 .
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran/tetrahydrofuran): δ P −19.8
(1P, s)
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran/tetrahydrofuran): δ H 6.25 (3H,
3 3 3 dd, J (cis) = 11.8, J (trans) = 18.4, P(C HCH 2 ) 3 ), 5.71 (3H, dd, J (gem) = 2.1,
P(CHCH H c i s ) 3 ), 5.55 (3H, dd, P(CHCH H trans ) 3 )
i 7 7.2.8 Lithium diisopropylamide, Li( Pr) 2 N
Methyllithium (1.5 M, stabilized with LiBr, 10 mL, 0.015 mol) was added to diisopropylamine (2.75 mL, 0.20 mol) in tetrahydrofuran (20 mL) at
230 Chapter 7 Experimental
−78˚C. The reaction mixture was stirred at −78˚C for 30 minutes, then allowed to warm with stirring to 0˚C over an additional 30 minutes. The mixture was evaporated to dryness in vacuo , leaving an off white solid which was dissolved in dry tetrahydrofuran ( ca. 75 mL). The concentration of lithium diisopropylamide was determined via titration to be 0.20 M (1.6 g, ~100%).
7.2.9 Titration of lithium diisopropylamide 8
An accurately measured aliquot of lithium diisopropylamide solution ( ca.
5.0 mL) was added to 1,10 phenanthroline (2 mg) and the deep burgundy solution diluted with dry tetrahydrofuran (10 mL). Dry tert butyl alcohol was added dropwise until the solution turned colourless, and the initial
LDA concentration determined on the basis of 1:1 complexation.
2 7.2.10 Tris ((dimethylphosphino)ethyl)phosphine (P P 3 ’),
9 P(CH 2 CH 2 PMe 2 ) 3
Dimethylphosphine (16 g, 0.26 mol, 4.6 eq.) was trap to trap distilled under static vacuum to a Schlenk flask held at −78˚C. A solution of trivinylphosphine (6.3 g, 0.056 mol) in tetrahydrofuran ( ca. 100 mL) was added via cannula and lithium diisopropylamide (0.2 M in tetrahydrofuran, 70 mL, 0.014 mol) was added. The yellow solution was stirred for one hour, then allowed to warm with stirring to room temperature over 14 hours. The yellow solution was cooled again to
231 Chapter 7 Experimental
−78˚C and dry methanol added carefully until effervescence ceased. The colourless solution was evaporated to dryness in vacuo and the white solid dissolved in dry benzene ( ca. 40 mL, some white lithium salts remain). The solution was filtered and the solvent removed in vacuo to give tris ((dimethylphosphino)ethyl)phosphine as a white solid (10 g,
60%).
NOTE: Traces of diisopropylamine and/or lithium salts still remaining can be removed by carefully washing a benzene solution of the mixture with deoxygenated water and thoroughly drying the washed product, via either
Dean Stark distillation or drying the solid under vacuum over phosphorus pentoxide.
3 1 1 3 P{ H} NMR (162 MHz, C 6 D 6 ): δ P −19.8 (1P, q, J (P P) = 20.7, P c ), −48.5
(3P, d, PMe 2 )
1 3 1 H{ P} NMR (400 MHz, C 6 D 6 ): δ H 1.47 (6H, m, C H 2 ), 1.37 (6H, m, C H 2 ),
0.83 (18H, s, CH 3 )
2 7.2.11 Tris ((diphenylphosphino)ethyl)phosphine (P P 3 ),
P(CH 2 CH 2 PPh 2 ) 3
Tris ((diphenylphosphino)ethyl)phosphine was prepared as per the
2 preparation of P P’ 3 , using diphenylphosphine in place of dimethylphosphine (15.2g, 70%).
232 Chapter 7 Experimental
3 1 1 3 P{ H} NMR (162 MHz, C 6 D 6 ): δ P −8.2 (3P, d, J (P P) = 24.9, PPh 2 ), −12.9
(1P, q, P c )
1 3 1 H{ P} NMR (400 MHz, C 6 D 6 ): δ H 7.48 (12H, app. dd, Ar H o ), 7.27 (6H, bs,
Ar H p ), 7.16 (12H, m, Ar H m ), 2.08 (6H, m, C H 2 ), 1.54 (6H, m, C H 2 )
7.2.12 Tris (s ec (dimethylphosphino)propyl)-phosphine
3 (sec -P P’ 3 ), P(CH 2 CH(Me)PMe 2 ) 3
A mixture of tris (s ec (dimethylphosphino)propyl) phosphine stereomers
(5:3 RRR /SSS:RRS /SSR ) was prepared via a modification of the
2 preparation of P P’ 3 . Triallylphosphine was used in place of trivinylphosphine, and was pre mixed with lithium diisopropylamide before the addition of dimethylphosphine.
NOTE: 3 1 P{ 1 H} NMR integration of RRS /SSR isomer reflects that the
observed resonances are in fact an overlapping 2:1:1/1:2:1 ( P t :P t * :P c ) system.
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran/tetrahydrofuran): δ P −36.3
3 (1½P, d, J (P P) = 18.4, RRS /SSR P(CH 2 CH(CH 3 )P(CH 3 ) 2 ) 3 ), −36.4 (1½P, d,
3 J (P P) = 16.5, RRS /SSR P(CH 2 CH(CH 3 )P(CH 3 ) 2 ) 3 ), −36.7 (3P, d,
3 J (P P) = 16.1, RRR/SSS P(CH 2 CH(CH 3 )P(CH 3 ) 2 ) 3 ), −42.9 (1P, app. q,
3 J (P P) = 16.5/18.4, RRS /SSR P (CH 2 CH(CH 3 )P(CH 3 ) 2 ) 3 ), −44.7 (1P, q,
3 J (P P) = 16.0, RRR/SSS P (CH 2 CH(CH 3 )P(CH 3 ) 2 ) 3 )
233 Chapter 7 Experimental
1 3 1 H{ P} NMR (400 MHz, C 6 D 6 ): δ H 1.58 1.16 (9H, m), 1.16 1.09 (9H, m),
0.89 0.76 (18H, m)
7.2.13 Reaction of triallylphosphine with lithium
diisopropylamide
An excess of lithium diisopropylamide (50 mg) was added to a sample of
distilled triallylphosphine ( ca. 5 mg) in d 8 tetrahydrofuran (1 mL) and the suspension stirred for five minutes before filtering. The reaction was monitored via 3 1 P NMR. After one hour, less than 5% triallylphosphine remained, with the formation of three new resonances downfield that were the result of sequential double bond migration
(cf. trivinylphosphine δ P = −19.8). Additional reaction time led to a complex mixture of many degradation products.
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran): δ P −15.3 (s, P(CHCHCH 3 ) 3 ),
−18.0 (s, P(CHCHCH 3 ) 2 (CH 2 CHCH 2 )), −20.0 (s, P(CHCHCH 3 )(CH 2 CHCH 2 ) 2 ),
−38.2 (s, P(CH 2 CHCH 2 ) 3 )
1 0 7.2.14 Tris (3-hydroxypropyl)amine, N(CH 2 CH 2 CH 2 OH) 3
3 Propanolamine (10.0 mL, 131 mmol), 3 chloropropanol (25.4 mL,
304 mmol) and sodium carbonate (33.4 g, 315 mmol) in absolute ethanol
(75 mL) was heated at reflux for 24 hours, allowed to cool to room temperature and anhydrous chloroform was added (120 mL). The mixture
234 Chapter 7 Experimental
was briefly agitated, filtered and the filtrate concentrated in vacuo . The concentrated crude oil was distilled under vacuum (0.4 mmHg, up to
164 °C), removing residual starting material and bis (3 hydroxypropyl)amine. The remaining undistilled viscous yellow oil was tris (3 hydroxypropyl)amine (12.5 g, 50%).
1 3 1 C{ H} NMR (101 MHz, CDCl 3 ): δ C 61.6 (s, CH 2 OH), 52.0 (s, N CH 2 ), 28.7
(s, CH 2 CH 2 CH 2 )
1 3 H NMR (400 MHz, CDCl 3 ): δ H 3.65 (6H, t, J (H H) = 6.7, CH 2 OH), 2.55 (6H,
3 t, J (H H) = 6.6, NC H 2 ), 1.70 (6H, app. p, splitting = 6.7, CH 2 CH 2 CH 2 )
1 0 7.2.15 Tris (3-bromopropyl)amine, N(CH 2 CH 2 CH 2 Br) 3
Phosphorus tribromide (25.0 mL, 263 mmol) was added to tris (3 hydroxypropyl)amine (12.5 g, 65.2 mmol) in anhydrous chloroform
(100 mL) with stirring mixture, forming a white solid film. The mixture was gently heated to reflux, stirring with some difficulty until the solid film broke, at which point the mixture stirred freely and began to reflux vigorously. The initial reaction subsided after a short period, and the reaction mixture was left heating at reflux overnight, during which the solution turned orange and a white solid deposited on the walls of the vessel. The reaction mixture was allowed to cool to room temperature,
and the excess PBr 3 destroyed carefully with absolute ethanol (100 mL) with the generation of HBr gas. The solvent was removed in vacuo , and the residue dissolved in dichloromethane (200 mL). The dichloromethane
235 Chapter 7 Experimental
solution was washed with half saturated aqueous sodium carbonate
(400 mL), with the evolution of CO 2 gas. The solvent was removed in vacuo to give crude tris (3 bromopropyl)amine as a yellow oil which was used directly in the preparation of tris (3 (diphenylphosphino)propyl)amine.
1 3 1 C{ H} NMR (101 MHz, CDCl 3 ): δ C 51.1 (N CH 2 ), 31.7 (CH 2 CH 2 CH 2 ), 29.8
(CH 2 Br)
1 3 H NMR (400 MHz, CDCl 3 ): δ H 3.19 (6H, t, J (H H) = 6.3, C H 2 Br), 2.25 (6H,
3 t, J (H H) = 6.5, NC H 2 ), 1.69 (6H, app. p, splitting = 6.4, CH 2 CH 2 CH 2 )
3 7.2.16 Tris (3-(diphenylphosphino)propyl)amine (N P 3 ),
N(CH 2 CH 2 CH 2 PPh 2 ) 3
Diphenylphosphine (15.3 g, 82.3 mmol) and dry potassium tert butoxide
(23.7 g, 211 mmol) in tetrahydrofuran (150 mL) was stirred for
15 minutes, by which time the colourless solution had turned an intense deep red colour, indicating formation of potassium diphenylphosphide.
Tris (3 bromopropyl)amine (10.3 g, 27.2 mmol) in tetrahydrofuran (50 mL) was added and the combined solutions rapidly turned pale milky yellow.
The mixture was heated at reflux for 12 hours. The solution was allowed to cool to room temperature and the solvent removed in vacuo . The residue was dissolved in boiling absolute ethanol (400 mL), filtered while hot, and cooled slowly to −18°C. The resulting white frozen oil was filtered off, and recrystallised in a similar manner an additional two
236 Chapter 7 Experimental
times to give a extremely viscous white oil that partially solidified over time (8.71 g, 46%).
3 1 1 P{ H} NMR (162 MHz, CDCl 3 ): δ P −16.1 (1P, s)
1 3 1 1 C{ H} NMR (101 MHz, CDCl 3 ): δ C 138.8 (d, J (P C) = 13.0, Ar C i ), 132.6
2 3 (d, J (P C) = 18.3, Ar C o ), 128.4 (d, J (P C) = 4.3, Ar C m ), 128.3 (s, Ar C p ),
2 3 54.7 (d, J (P C) = 14.0, N CH 2 ), 25.7 (d, J (P C) = 11.3, CH 2 CH 2 CH 2 ), 23.4 (d,
1 J (P C) =15.7, P CH 2 )
1 H NMR (400 MHz, CDCl 3 ): δ H 7.44 7.40 (12H, m, Ar H x ) 7.34 7.30 (18H,
m, Ar H x , p ), 2.43 (6H, app. t, splitting = 7.0, C H 2 PPh 2 ), 2.03 (6H, m,
PC H 2 ), 1.53 (6H, b.m, CH 2 CH 2 CH 2 )
7.2.17 (2-bromophenyl)diphenylphosphine,
1 1 Ph 2 P( o-C 6 H 4 Br)
Diphenylphosphine (16 mL, 89 mmol) was to a solution of palladium(II) acetate (0.10 g, 0.46 mmol), sodium acetate (8.3 g, 100 mmol) and ortho bromoiodobenzene (11 mL, 89 mmol) in dimethylformamide (50 mL). and the solution stirred at 120°C for five days. The deep red solution was cooled to room temperature, diluted with water (80 mL) and extracted with chloroform (3 x 100 mL). The combined organic fractions were dried over magnesium sulfate and evaporated to dryness, affording a mixture of red and white solids which was purified by flash chromatography on silica (1:2 ethyl acetate:hexane). Concentration of the fractions
237 Chapter 7 Experimental
containing pure (2 bromophenyl)diphenylphosphine (R f = 0.60) gave the desired product as a white powder (23 g, 77%).
3 1 1 P{ H} NMR (162 MHz, CDCl 3 ): δ P −5.3 (1P, s)
1 3 1 H{ P} NMR (400 MHz, CDCl 3 ): δ H 7.59 (1H, m, PC 6 H 3 6 H 2 Br), 7.40
7.12 (12H, m, P Ph 2 /PC 6 H 2 5 H 6 H 2 Br), 6.52 (1H, m, PC 6 H 3 5 H 2 Br)
7.2.18 1-(phenyl(2-(diphenylphosphino)phenyl)-
phosphino)-2-(diphenylphosphino)benzene
1 2 (triphos**), Ph 2 P( o-C 6 H 4 )PPh( o-C 6 H 4 )PPh 2
(2 Bromophenyl)diphenylphosphine (6.1 g, 18 mmol) was dissolved in tetrahydrofuran and the colourless solution cooled to −35°C. n Butyllithium in hexanes (1.54 M by titration, 12 mL, 18 mmol) was added dropwise over one hour via syringe pump and stirred for an additional
15 minutes. Dichlorophenylphosphine (1.4 mL, 8.4 mmol) was added dropwise over one hour to the deep red solution at −20°C. The resulting yellow/white suspension was stirred at room temperature for 14 hours.
Chloroform (100 mL) was added to the thick white suspension and the organic layer washed with water (2 x 50 mL). The solvent was removed in vacuo to give 7.7 g of crude white solid. The sample was dry loaded onto silica using chloroform and purified via flash chromatography.
Triphenylphosphine and (2 bromophenyl)diphenylphosphine were eluted from the column using 800 mL 3:1 hexane:dichloromethane and 1600 mL of 1:1 hexane:dichloromethane, then triphos** stripped from the column
238 Chapter 7 Experimental
with 2000 mL of dichloromethane. Evaporation of the fractions containing pure triphos** gave a white solid, which was washed with pentane (3 x 20 mL) and dried under a stream of nitrogen (3.3 g, 63%).
3 1 1 3 P{ H} NMR (162 MHz, CDCl 3 ): δ P −13.9 (2P, AA’ X, J (P P) = 155.3,
6 J (P P) = 20.7, Ph 2 P), −17.5 (1P, AA’ X, P c )
1 3 1 H{ P} NMR (400 MHz, CDCl 3 ): δ H 7.23 7.05 (33H, m)
7.3 Metal Complex Precursors
7.3.1 Dichloro tris (triphenylphosphine)ruthenium(II),
1 3 [RuCl 2 (PPh 3 ) 3 ]
A solution of ruthenium trichloride trihydrate (3.0 g, 12 mmol) and triphenylphosphine (18 g, 69 mmol) in methanol (300 mL) was heated at reflux for 14 hours, after which there was copious fine brown precipitate in a dirty yellow solution. After cooling the solid was isolated by filtration and washed with diethyl ether (2 x 60 mL), pentane (2 x 60 mL) and dried to give a fine brown microcrystalline solid (11 g, 99%).
ν IR m a x (KBr): 1967 (w), 1894 (w), 1826 (w), 1774 (w), 1479 (st, sh), 1432
(st, sh), 1316 (w), 1268 (w), 1188 (m), 1156 (w), 1088 (st, sh), 1027 (w),
998 (m), 924 (w), 853 (w), 743 (st), 695 (st), 543 (m, sh), 519 (st), 496
(st), 453 (m)
239 Chapter 7 Experimental
7.3.2 Chlorohydrido tris (triphenylphosphine)-
1 4 ruthenium(II), [RuHCl(PPh 3 ) 3 ]
A solution of sodium borohydride (0.13 g, 3.3 mmol) in deoxygenated water (2 mL) was added to a solution of dichloro tris (triphenylphosphine)ruthenium(II) (0.62 g, 0.65 mmol) in benzene (60 mL) and the mixture stirred for 20 minutes, during which time the initial brown solution turned violet. The solution was heated at reflux for two hours and concentrated in vacuo to approximately 20 mL.
Hexane (5 mL) was added and the solid precipitate filtered off and washed with additional hexane to give a bright purple solid (0.19 g, 32%).
3 1 1 P{ H} NMR (162 MHz, CDCl 3 ): δ P 58.0 (4P, b.s)
1 3 H NMR (400 MHz, CDCl 3 ): δ H 7.24 (18H, d, J (H H) = 7.7, Ar H m ), 7.18 (9H,
3 3 t, J (H H) = 7.4, Ar H p ), 6.98 (18H, app. t, J (H H) = 7.6, Ar H o ), −17.78 (1H,
2 q, J (H P) = 25.7, Ru H)
ν IR m a x (KBr): 1479 (m), 1434 (st, sh), 1386 (m), 1310 (w), 1264 (w), 1185
(m), 1158 (w), 1120 (m), 1091 (m), 1029 (m), 998 (w), 853 (w), 745 (st),
722 (m), 695 (st), 679 (st), 617 (w), 541 (st), 523 (st), 510 (st), 457 (m),
437 (w)
240 Chapter 7 Experimental
7.3.3 Trans -dichloro bis (1,2-bis (dimethylphosphino)-
1 5 , 1 6 ethane)ruthenium(II), [RuCl 2 (dmpe) 2 ]
Method 1
A solution of dichloro tris (triphenylphosphine)ruthenium(II) (4.5 g,
4.6 mmol) and 1,2 bis (dimethylphosphino)ethane (1.4 g, 9.4 mmol) in acetone (150 mL) was heated at reflux for 16 hours. The opaque yellow solution was cooled, concentrated in vacuo to approximately 15 mL and the yellow solid filtered off. The product was washed with pentane
(3 x 25 mL) and dried (2.1 g, 94%).
Method 2
Ruthenium trichloride trihydrate (1.1 g, 4.2 mmol) and
1,2 bis (dimethylphosphino)ethane (1.9 g, 12.7 mmol) were dissolved in a mixture of water (30 mL) and ethanol (160 mL). The initially brown solution was heated at reflux for 14 hours to afford a golden yellow solution, and the solvent was removed in vacuo . The residue was extracted with warm benzene ( ca. 100 mL) and the yellow solution decanted from the orange oil/gum. The benzene was removed in vacuo and the canary yellow powder washed with pentane (2 x 30 mL) and dried
(1.4 g, 70%).
3 1 1 P{ H} NMR (162 MHz, C 6 D 6 ): δ P 38.7 (4P, s)
241 Chapter 7 Experimental
1 3 1 H{ P} NMR (400 MHz, C 6 D 6 ): δ H 1.49 (8H, m, PC H 2 ), 1.35 (24H, s, PC H 3 )
ν IR m a x (ATR): 1419 (m), 1292 (m, sh), 1277 (m, sh), 1234 (w, sh), 1124
(w), 1076 (w), 937 (st), 924 (st), 890 (st, sh), 839 (m, sh), 797 (w), 736 (m, sh), 705 (m, sh)
7.3.4 Trans-dichloro bis (1,2-bis (diethylphosphino)ethane)-
ruthenium(II), [RuCl 2 (depe) 2 ]
Ruthenium trichloride trihydrate (1.4 g, 5.3 mmol) and
1,2 bis (diethylphosphino)ethane (3.2 g, 16 mmol) were dissolved in a mixture of water (30 mL) and ethanol (160 mL). The initially brown solution was heated at reflux for 14 hours to afford a clear yellow solution, and the solvent was removed in vacuo . The residue was extracted with warm benzene ( ca. 100 mL) and the yellow solution decanted from the red oil/gum. The benzene was removed in vacuo and the canary yellow powder washed with pentane (2 x 30 mL) and dried
(3.0 g, 95%).
3 1 1 P{ H} NMR (162 MHz, C 6 D 6 ): δ P 48.0 (4P, s)
1 3 1 2 H{ P} NMR (400 MHz, C 6 D 6 ): δ H 2.56 (8H, dq, J ( g e m ) = 14.9,
3 J = 7.6) PC HHCH ), 2.0 (8H, dq, 3 J = 7.5, PCHHCH ), 1.88 ( H C H 3 ) 3 ( H C H 3 ) 3
(8H, m, PC H 2 CH 2 P), 1.28 (24H, app. t, splitting = 7.7, C H 3 )
242 Chapter 7 Experimental
ν IR m a x (ATR): 1461 (m), 1414 (m), 1374 (w), 1273 (w), 1249 (w, b), 1120
(w, b), 1082 (w), 1032 (st), 984 (w), 873 (w), 821 (w), 759 (m), 731 (st),
699 (m), 684 (m), 668 (m)
7.3.5 Trans -chlorohydrido bis (1,2-bis (dimethylphosphino)-
1 7 ethane)ruthenium(II), [RuHCl(dmpe) 2 ]
1,2 bis (dimethylphosphino)ethane (0.15 g, 1.0 mmol) was added to a solution of chlorohydrido tris (triphenylphosphine)ruthenium(II) (0.19 g,
0.21 mmol) was dissolved in acetone (30 mL) and. The purple solution was heated at reflux for two hours, during which time the solution turned light green. The solvent was removed in vacuo and the resulting gum washed thoroughly with pentane (0.018 g, 20%).
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran): δ P 39.3 (4P, s)
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): δ H 1.76 (8H, s, PC H 2 ), 1.44
(24H, s, PC H 3 ), −20.80 (1H, s, Ru H)
7.3.6 Cis -dihydrido bis (1,2-bis (dimethylphosphino)-
1 8 ethane)ruthenium(II), [RuH 2 (dmpe) 2 ]
Trans-dichlorob is (1,2 bis (dimethylphosphino)ethane)ruthenium(II) (0.24 g,
0.51 mmol) was dissolved in an isopropanol/tetrahydrofuran mixture
(2:49, 30 mL) and stirred for one hour. Fine sodium chunks (2.1 g,
90 mmol) were added, and the mildly effervescing reaction mixture
243 Chapter 7 Experimental
stirred for 14 hours to give a grey suspension. The solvent was removed in vacuo and the residue was extracted in pentane (30 mL) and filtered to give a clear colourless filtrate. Evaporation of the solution in vacuo to
dryness afforded cis [RuH 2 (dmpe) 2 ] as a white powder (0.14 g, 68%).
NOTE: In C 6 D 6 there exists 5% of the trans isomer
3 1 1 P{ H} NMR (162 MHz, C 6 D 6 ): δ P 47.3 (2P, app. t, splitting = 21.5), 38.3
(2P, app. t, splitting = 21.5)
1 3 1 H{ P} NMR (400 MHz, C 6 D 6 ): δ H 1.66 1.25 (8H, m, PC H 2 ), 1.44 1.18
(24H, m, P CH 3 ), −10.11 (2H, s, 2 x Ru H)
7.3.7 Cis-dihydrido bis (1,2-bis (diethylphosphino)ethane)-
ruthenium(II), [RuH 2 (depe) 2 ]
Cis-di hydrido bis (1,2 bis (diethylphosphino)ethane)ruthenium(II) was
prepared via the same procedure as for [RuH 2 (dmpe) 2 ] (76%).
NOTE: In C 6 D 6 there exists 24% of the trans isomer
3 1 1 P{ H} NMR (162 MHz, C 6 D 6 ): δ P 75.5 (2P, app. t, splitting = 18.2), 62.5
(2P, app. t, splitting = 18.2)
1 3 1 H{ P} NMR (400 MHz, C 6 D 6 ): selected δ H 1.80 0.91 (32H, m,
PC H 2 /PC H 3 ), −10.76 (2H, s, Ru H)
244 Chapter 7 Experimental
7.3.8 Tri -µµµ-chloro-hexakis (dimethylphenylphosphine)
diruthenium(II) chloride,
µµµ 1 9 [{(PMe 2 Ph) 3 Ru} 2 ( -Cl) 3 ]Cl
Dimethylphenylphosphine (20 g, 145 mmol) was added to a solution of ruthenium trichloride trihydrate (6.1 g, 23 mmol) in 2 methoxyethanol
(200 mL). The very dark brown solution was heated at reflux for one hour, during which time it cleared to a deep yellow colour. The solution was concentrated four fold and diethyl ether (50 mL) was added. The solution was cooled to −20°C and the solid precipitate collected as a yellow powder. The solid was washed with diethyl ether (2 x 50 mL) and dried under vacuum and used without further purification (13 g, 47%).
3 1 1 P{ H} NMR (202 MHz, CDCl 3 , 298 K): δ P 20.8 (1P, s)
1 3 1 H{ P} NMR (500 MHz, CDCl 3 , 298 K): δ H 7.39 (6H, t, 7.3, Ar H p ), 7.26
(12H, t, 7.5, Ar H m ), 7.09 (12H, m, Ar H o ), 1.66 (36H, s, PCH 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 378 ([Ru(PMe 2 Ph) 2 ] , 100%), 413
+ + ([RuCl(PMe 2 Ph) 2 ] , 21%), 448 ([RuCl 2 (PMe 2 Ph) 2 ] , 8%), 551
+ + ([RuCl(PMe 2 Ph) 3 ] , 81%), 586 ([RuCl 2 (PMe 2 Ph) 3 ] , 19%)
ν IR m a x (KBr): 1433 (m, sh), 1097 (m), 939 (st, sh), 904 (st), 745 (m), 706
(st), 677 (m, sh), 493 (m, sh), 419 (m, sh)
245 Chapter 7 Experimental
7.3.9 Cis -dichloro bis (1,2-bis (dimethylphosphino)ethane)-
1 6 ruthenium(II), cis -[RuCl 2 (dmpe) 2 ]
Tri µ chloro hexakis (dimethylphenylphosphine)diruthenium(II) chloride
(9.6 g, 8.2 mmol) was combined with 1,2 bis (dimethylphosphino)ethane
(5.0 g, 33 mmol) and the solid paste heated slowly to 200 °C. Reaction began at 130 °C, forming a clear light yellow solution which precipitated a cream solid upon cooling. The solid was broken up and washed with pentane, filtered and dried under vacuum (7.2 g, 93%).
NOTE: The product contains approximately 5% of the trans isomer
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 298 K): δ P 50.6 (2P, app. t,
splitting = 26.2, P equatorial ), 41.4 (2P, app. t, splitting = 23.2, P axial )
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 298 K): δ H 1.92 (2H, d.t,
3 3 J (HH) = 5.7, J (HH) = 13.2, PC HH), 1.67 (4H, m, PC H 2 ), 1.63 (6H, s, PC H 3 ),
1.47 (2H, m, PCHH), 1.44 (6H, s, PC H 3 ), 1.43 (6H, s, PC H 3 ), 1.31 (6H, s,
PC H 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 437 ([RuCl(dmpe) 2 ] , 100%)
ν IR m a x (ATR): 1412 (m, b), 1300 (m), 1285 (m), 1271 (m), 1071 (w), 928
(st), 909 (m), 892 (st), 834 (m), 733 (m), 701 (m)
246 Chapter 7 Experimental
7.3.10 Cis -dichloro bis (1,2-bis (diethylphosphino)ethane)
ruthenium(II), cis -[RuCl 2 (depe) 2 ]
Procedure as per the preparation of cis [RuCl 2 (dmpe) 2 ] (88%).
NOTE: The product contains approximately 32% of the trans isomer
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 298 K): δ P 59.8 (2P, app. t,
splitting = 22.4, P equatorial ), 47.8 (2P, app. t, splitting = 22.4, P axial )
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 298 K): δ H 2.54 (2H, app. hex., splitting = 7.3), 2.24 (4H, app. hex., splitting = 7.4), 2.18 (2H, app. hex., splitting = 7.7), 1.86 2.56 (12H, m), 1.50 (2H, app. d.t, splitting = 13.2, 4.5), 1.32 (2H, app. d.t, splitting = 12.9, 5.4), 1.21
(12H, app. q, splitting = 6.7, CH 2 CH 3 ), 1.07 (6H, app. t, splitting = 7.6,
CH 2 CH 3 ), 1.03 (6H, app. t, splitting = 7.6, CH 2 CH 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%)
7.4 Ruthenium Complexes of Triphos**
7.4.1 Reaction of dichloro tris (triphenylphosphine)-
ruthenium(II) with triphos** in acetone
A solution of dichlorotris(triphenylphosphine)ruthenium(II) (0.13 g,
0.13 mmol) and triphos** (0.11 g, 0.17 mmol) in acetone (60 mL) was
247 Chapter 7 Experimental
heated at reflux for 14 hours. The resulting yellow solution was evaporated to dryness in vacuo and the orange/yellow solid washed with
hot hexane (80 mL) to give mer [RuCl 2 (triphos**)] (0.10 g, 96%).
3 1 1 3 P{ H} NMR (162 MHz, d 6 acetone): δ P 97.1 (1P, t, J (P P) = 24.9, P c ), 72.9
(2P, d, P t )
1 3 1 H{ P} NMR (400 MHz, d 6 acetone): δ H 8.03 6.61 (33H, m)
+ MS (+ MALDI TOF, C 6 0 matrix): 732 ([Ru(Triphos**)] , 100%), 767
([RuCl(Triphos**)] + , 44%)
7.5 Direct Reaction with Ruthenium Dichlorides
7.5.1 Reaction of trans -dichloro bis (1,2-bis (dimethyl-
phosphino)ethane) ruthenium(II) with hydrazine
Hydrazine solution (1M in tetrahydrofuran, 250 L, 250 mol) was added to trans-dichloro bis (1,2 bis (dimethylphosphino)ethane)ruthenium(II)
(30 mg, 63 mol) in d 8 tetrahydrofuran ( ca. 1 mL) in an NMR tube. The reaction was monitored by 3 1 P NMR and no reaction was observed within two weeks at room temperature, nor after heating the sample at 60˚C for
48 hours.
248 Chapter 7 Experimental
7.5.2 Reaction of trans -chlorohydrido bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with hydrazine
An excess of hydrazine (1M in tetrahydrofuran, ca. 0.4 mmol) was added to a solution of trans-chlorohydrido bis (1,2 bis (dimethylphosphino)ethane)ruthenium(II) (38 mg, 0.087 mmol) in
d 8 tetrahydrofuran ( ca. 1 mL) in an NMR tube. Monitoring the reaction via
3 1 P NMR showed no reaction over the course of a month.
7.5.3 Reaction of cis-dihydrido bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with hydrazine
An excess hydrazine (1M in tetrahydrofuran, 100 L, 0.1 mmol) was added to a solution of cis dihydrido bis (1,2 bis (dimethylphosphino)
ethane)ruthenium(II) (50 mg, 0.12 mmol) in d 8 tetrahydrofuran (ca. 1 mL) in an NMR tube. No reaction was observed via 3 1 P NMR after three days.
7.5.4 Reaction of cis -dihydrido bis (1,2-bis (diethyl-
phosphino)ethane) ruthenium(II) with triflic acid
Trifluoromethylsulfonic acid (50 L, 0.57 mmol) was added to a solution of cis-dihydrido bis (1,2 bis (diethylphosphino)ethane)ruthenium(II) (0.25 g,
0.48 mmol) in tetrahydrofuran (80 mL). The reaction mixture was stirred at room temperature under a stream of nitrogen gas for 14 hours to give a blue solution indicative of the presence of Ru I I I species. The 3 1 P{ 1 H}
249 Chapter 7 Experimental
NMR spectra show numerous products, with the major observable species being the protonated complex
κ 1 [RuH(depe) 2 ( (Et) 2 PCH 2 CH 2 (H)P(Et) 2 )](OTf) 2 .
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran): δ P 59.4 (4P, dd,
3 J = 5.8, 3 J = 23.2, κ 2 (Et) PCH CH P(Et) ), 52.4 (1P, b, ( P P trans ) ( P P c i s ) 2 2 2 2
κ 1 ((Et) 2 PCH 2 )), 2.9 (1P, b, CH 2 (H) P(Et) 2 )
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): δ H 2.10 0.91 (72H, m),
−13.46 (dp, 3 J = 23.2, 3 J = 69.6, Ru H) ( H P c i s ) ( H P trans )
7.6 Synthesis of Chloride Abstraction Reagents
2 0 7.6.1 Thallium(I) triflate, Tl(CF 3 SO 3 )
Trifluoromethylsulfonic acid (1.0 mL, 11 mmol) was added to thallium(I) carbonate (2.0 g, 4.2 mmol) in acetonitrile (50 mL). The suspension was stirred until effervescence ceased, by which stage the mixture was a clear colourless solution. The solution was filtered, then cooled to −30°C for
30 minutes and diethyl ether (15 mL) added. After an additional
30 minutes at −30°C the white crystalline solid formed was filtered off and vacuum dried for three hours (2.2 g, 73%).
Elemental analysis: calculated for C 1 F 3 O 3 S 1 Tl 1 , C 3.40, H nil, F 16.13%; found, C 3.54, H nil, F 16.37%
250 Chapter 7 Experimental
2 1 7.6.2 Isopropylmagnesium(II) chloride, Me 2 CHMgCl
A solution of isopropylchloride (4 mL, 44 mmol) in tetrahydrofuran
(40 mL) was added dropwise over two hours to activated magnesium turnings (1.3 g, 52 mmol) in tetrahydrofuran (50 mL). The resulting dark grey solution was stirred for 14 hours, filtered and the concentration of i PrMgCl determined via titration 2 2 against menthol (50 mg) and
1,10 phenanthroline (20 mg) in tetrahydrofuran (20 mL) until violet endpoint, giving a calculated concentration of 0.36M (~74%).
The solution was used directly in the preparation of tetrakis (3,5 bis (trifluoromethyl)phenyl)borate.
7.6.3 Sodium tetrakis (3,5-bis (trifluoromethyl)phenyl)-
2 3 borate, Na[B(3,5-(CF 3 ) 2 C 6 H 3 ) 4 ]
3,5 bis (trifluoromethyl)bromobenzene (24 mL, 0.14 mol) was dissolved in tetrahydrofuran (100 mL) and the solution cooled to −25°C. A solution of isopropylmagnesium(II) chloride (0.79M in tetrahydrofuran, 200 mL,
0.16 mol) was added dropwise over the course of three hours. The reaction mixture was stirred for an additional hour at −25°C, then warmed to room temperature over 30 minutes. Sodium tetrafluoroborate
(2.7g, 24 mmol) was added and the reaction mixture stirred at room temperature for 60 hours. The pale yellow solution was poured into a solution of sodium bicarbonate (40 g) and sodium hydrogen carbonate
(20 g) in distilled water (600 mL) and stirred vigorously for one hour. The
251 Chapter 7 Experimental
mixture was extracted with diethyl ether (4 x 200 mL) and dichloromethane (1 x 200 mL) and the combined organic fractions dried over sodium sulfate. The solvent was removed via rotary evaporator, giving a mixture of white solid and malodorous yellow oil. The remaining residual solvent was removed in vacuo , and the residue heated at reflux in chloroform (50 mL) for 10 minutes, before being cooled to 0°C and
filtered. Na[B(3,5 (CF 3 ) 2 C 6 H 3 ) 4 ] was obtained as a white solid which was washed with chloroform (20 mL), dried in vacuo and used without further purification (6.7 g, 31%).
1 1 1 B{ H} NMR (128 MHz, d 8 tetrahydrofuran): δ B −4.0 (1B, s)
1 H NMR (400 MHz, d 8 tetrahydrofuran): δ H 7.77 (8H, bs, Ar H o ), 7.56 (4H,
s, Ar H p )
2 4 7.6.4 [H(OEt 2 ) 2 ][B(C 6 H 3 (CF 3 ) 2 ) 4 ]
Sodium tetrakis (3,5 bis (trifluoromethyl)phenyl)borate (2.1 g, 2.4 mmol) was dissolved in diethyl ether (60 mL) and the solution cooled to −20°C.
Hydrogen chloride solution (2M in Et 2 O, 2.0 mL, 4.0 mmol) was added, precipitating sodium chloride, and the reaction mixture stirred for
20 minutes, then filtered. The residue was extracted with cold diethyl ether (2 x 25 mL), and the combined ethereal solution evaporated to dryness in vacuo to give a fine white powder which was used directly in
the preparation of Tl[B(3,5 (CF 3 ) 2 C 6 H 3 ) 4 ] (2.0 g, 82%).
252 Chapter 7 Experimental
7.6.5 Thallium tetrakis (3,5-bis (trifluoromethyl)phenyl)-
2 5 borate, Tl[B(3,5-(CF 3 ) 2 C 6 H 3 ) 4 ]
Thallium(I) carbonate (0.43 g, 0.92 mmol) and [H(OEt 2 ) 2 ][B(C 6 H 3 (CF 3 ) 2 ) 4 ]
(2.0 g, 2.0 mmol) were combined in acetonitrile (70 mL), and the white suspension stirred at room temperature for 10 minutes, giving a clear solution. The solvent was removed in vacuo to afford a white powder which was used without further purification (2.0 g, 95%).
1 3 1 H{ P} NMR (400 MHz, CDCl 3 ): 7.93 (8H, b.s, Ar H o ), 7.70 (4H, b.s,
Ar H p )
Elemental analysis: calculated for C 3 2 H 1 2 B 1 F 2 4 Tl 1 , C 36.00, H 1.13,
F 42.71%; found, C 38.19, H 1.49, F 37.99%
2 6 7.6.6 Thallium tetrafluoroborate, Tl(BF 4 )
Thallium granules (4.5 g, 22 mmol) were added to aqueous hydrofluoroboric acid (43%, 6.0 g, 29 mmol) and hydrogen peroxide (30% solution in water, ca. 2 mL) added dropwise carefully until effervescence ceased. 2,2 Dimethoxypropane (5 mL) and dry diethyl ether (50 mL) was added to the clear colourless solution. The mixture was stirred vigorously for five minutes, during which time a white precipitate formed. The
supernatant was decanted off. TlBF 4 was obtained as a white powder and was washed with dry diethyl ether (3 x 10 mL) and dried in vacuo (4.5 g,
70%). 253 Chapter 7 Experimental
Elemental analysis: calculated for B 1 F 4 Tl 1 , C nil, H nil; found, C <0.2,
H <0.2%
7.7 Reaction of ruthenium dichlorides with chloride
abstraction agents
7.7.1 Reaction of trans -dichloro bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with silver triflate
in dichloromethane
A solution of trans-dichloro bis (1,2 bis (dimethylphosphino)ethane) ruthenium(II) (1.4 g, 2.9 mmol) and silver triflate (0.75 g, 2.9 mmol) in dichloromethane (40 mL) was stirred for 20 hours, during which time the yellow solution changed to deep blue with formation of a grey (metallic silver) precipitate. The reaction mixture was filtered and the filtrate concentrated in vacuo to 15 mL and layered with diethyl ether (10 mL) to
I I I afford [Ru Cl 2 (dmpe) 2 ](OTf) as fine teal blue needles, which were isolated by filtration, washed with diethyl ether (2 mL), pentane (2 x 5 mL) and dried (1.6 g, 89%).
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): −14.13 (8H, b.s, PC H 2 CH 2 P),
−17.32 (24H, b.s, C H 3 )
254 Chapter 7 Experimental
ν IR m a x (KBr): 1423 (m), 1273 (st), 1263 (st, sh), 1244 (m), 1223 (m, sh),
1157 (m), 1148 (m), 1083 (w), 1032 (st, sh), 993 (w), 951 (st), 933 (m),
899 (m), 847 (w), 800 (w), 750 (m), 719 (m), 652 (w), 636 (st, sh), 573 (w),
517 (m), 455 (w)
Elemental analysis: calculated for C 1 3 H 3 2 Cl 2 F 3 O 3 P 4 Ru 1 S 1 , C 25.13,
H 5.19%; found, C 25.28, H 5.23%
7.7.2 Reaction of trans-dichloro bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with trimethylsilyl
triflate in toluene
Trimethylsilyl triflate (100 L, 0.55 mmol) was added to a solution of trans-dichloro bis (1,2 bis (dimethylphosphino)ethane)ruthenium(II) (0.25 g,
0.53 mmol) in toluene ( ca. 40 mL). The reaction mixture was stirred at room temperature for 14 hours, during which time the initially yellow solution formed a red oil which redissolved and eventually gave a teal blue solid and a yellow solution. The solid was collected on a sintered glass frit, washed with toluene (30 mL) and pentane (2 x 30 mL) then
I I I dried to give [Ru Cl 2 (dmpe) 2 ](OTf) (0.20 g, 65%).
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): −14.13 (8H, b.s, PC H 2 CH 2 P),
−17.32 (24H, b.s, C H 3 )
255 Chapter 7 Experimental
7.7.3 Reaction of trans-dichloro bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with thallium
triflate in tetrahydrofuran
A solution of trans-dichloro bis (1,2 bis (dimethylphosphino)ethane) ruthenium(II) (1.4 g, 3.0 mmol) and thallium triflate (1.1 g, 3.1 mmol) in tetrahydrofuran (50 mL) was heated at reflux for 14 hours, during which time a white precipitate formed. The yellow solution was cooled to room temperature and allowed to stand under nitrogen for a further 14 hours, during which time the solution turned green. The reaction mixture was filtered and the filtrate evaporated to dryness in vacuo to give a light
. green solid, [RuCl 2 (dmpe) 2 ] Tl(OTf) (1.4 g, 57%).
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran, 180 K): δ P 39.1 (4P, s)
+ MS (+ MALDI TOF, C 6 0 matrix): 437 ([RuCl(dmpe) 2 ] , 100%), 568
+ ([Ru(OTf)(OH)(dmpe) 2 ] , 24%)
ν IR m a x (KBr): 1420 (m), 1281 (st, b), 1231 (st, b), 1159 (st, b), 1078 (w),
1024 (st, sh), 841 (st), 930 (st), 893 (m), 839 (m, sh), 800 (w, b), 741 (m, sh), 708 (m, sh), 636 (st, sh), 571 (w), 517 (m), 455 (w)
7.7.4 Reaction of trans-dichloro bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with sodium
256 Chapter 7 Experimental
tetrakis (3,5-bis (trifluoromethyl)phenyl)borate in
methanol
A yellow solution of trans-dichloro bis (1,2 bis (dimethylphosphino)ethane) ruthenium(II) (0.071 g, 0.15 mmol) and sodium tetrakis (3,5 bis (trifluoromethyl) phenyl)borate (0.14 g, 0.16 mmol) in methanol (30 mL) was stirred at room temperature for 14 hours with no visible change. The solution was then heated at reflux for an additional
14 hours, again with no visible change. The solvent was removed in vacuo to give a yellow solid that slowly turned green after a few days when stored under an atmosphere of nitrogen. The solid was washed with benzene and dried to give a mixture of products, the major of which were
cis [RuCl 2 (dmpe) 2 ] and an unknown cis unsymmetrical complex
(Compound 1) (0.070 g).
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran): δ P 50.1 (2P, app. t,
splitting = 22.9, cis [RuCl 2 (dmpe) 2 ], P equatorial ), 40.7 (1P, ddd,
2 2 2 J (AB) = 31.1, J (AC) = 12.6, J (AD) = 19.8, Compound 1, A), 37.1 (2P, app. t,
2 2 cis [RuCl 2 (dmpe) 2 ], P axial ), 36.9 (1P, ddd, J (CB) = 33.1, J (CD) = −246.6,
2 Compound 1, C), 35.8 (1P, ddd, J (BD) = 23.6, Compound 1, D), 23.7 (1P, ddd, Compound 1, B)
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): δ H 7.79 (8H, b.s., Ar H o ),
7.58 (4H, b.s, Ar H p ), 1.27 (8H, b.s, PC H 2 CH 2 P), 0.86 (24H, b.s, PC H 3 )
257 Chapter 7 Experimental
+ MS (+ MALDI TOF, C 6 0 matrix): 437 ([RuCl(dmpe) 2 ] , 100%), 465
+ ([RuCl(N 2 )(dmpe) 2 ] , 40%)
IR ν (ATR): 2011 (m, ν ), 1964 (w, ν ), 1718 (w), 1611 (w), 1421 (w), m a x N 2 C O
1353 (m, sh), 1272 (st), 1113 (st, b), 930 (m), 886 (m), 838 (m), 744 (w),
713 (m), 682 (m, sh), 668 (m)
7.7.5 Reaction of trans-dichloro bis (1,2 -bis (dimethyl-
phosphino)ethane)ruthenium(II) with silver triflate
in methanol
A solution of trans-dichloro bis (1,2 bis (dimethylphosphino)ethane) ruthenium(II) (0.22 g, 0.46 mmol) and silver triflate (0.12 g, 0.45 mmol) in methanol (20 mL) was heated at reflux under a dinitrogen atmosphere for
14 hours. The resulting light blue solution with fine grey precipitate was filtered and the filtrate evaporated to dryness in vacuo . The light blue solid residue was washed with benzene (20 mL) and dried to give a
mixture of cis and trans [RuCl(OTf)(dmpe) 2 ] in a 8:1 ratio (0.13 g, 48%).
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 248 K): 54.1 (1P, ddd,
2 2 2 J (AB) = 36.5, J (AC) = 16.2, J (AD) = 24.8, cis [RuCl(OTf)(dmpe) 2 ], A), 53.5
2 2 (1P, ddd, J (BC) = 28.9, J (BD) = 18.2, cis [RuCl(OTf)(dmpe) 2 ], B), 43.2 (1P,
2 ddd, J (CD) = −315.8, cis [RuCl(OTf)(dmpe) 2 ], C), 39.4 (4P, s, trans
[RuCl(OTf)(dmpe) 2 ]), 35.0 (1P, ddd, cis [RuCl(OTf)(dmpe) 2 ], D)
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 198 K): δ H 1.68 1.17 (b.m)
258 Chapter 7 Experimental
+ MS (+ MALDI TOF, C 6 0 matrix): 437 ([RuCl(dmpe) 2 ] , 100%), 459 (34%),
+ 551 ([Ru(OTf)(dmpe) 2 ] , 31%)
ν IR m a x (ATR): 1478 (w), 1422 (m, b), 1288 (m), 1261 (m), 1240 (st), 1222
(m, sh), 1155 (st, b), 1080 (w, b), 1029 (st, sh), 993 (w), 930 (st, b), 895
(m), 837 (m, b), 798 (w), 737 (m), 705 (m), 680 (m, sh)
Elemental analysis: calculated for C 1 3 H 3 2 ClF 3 O 3 P 4 Ru 1 S 1 , C 26.65, H 5.51%; found: C 25.56, H 5.46%
7.7.6 Reaction of trans-dichloro bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with trimethylsilyl
triflate in methanol
A solution of trans-dichloro bis (1,2 bis (dimethylphosphino)ethane) ruthenium(II) (0.11 g, 0.24 mmol) in methanol (20 mL) was stirred under a dinitrogen atmosphere for 20 minutes before trimethylsilyl triflate
(52 L, 0.29 mmol) was added and the mixture stirred for 14 hours. The resulting teal blue solution was evaporated to dryness in vacuo and the resulting solid washed with benzene (20 mL) to give trans [RuCl(OTf)(dmpe)] (0.10 g, 73%).
3 1 1 P{ H} NMR (202 MHz, MeOH/MeOD, 198 K): δ P 30.8 (4P, s)
259 Chapter 7 Experimental
1 3 1 H{ P} NMR (500 MHz, MeOH/MeOD, 198 K): δ H 1.79 (8H, b.s,
PC H 2 CH 2 P), 1.41 (24H, b.s, PC H 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 437 ([RuCl(dmpe) 2 ] , 100%), 458 (33%),
522 (43%), 549 (44%), 568 (34%)
ν IR m a x (ATR): 1421 (m), 1259 (st), 1241 (m), 1222 (m), 1145 (st), 1084 (w),
1029 (st, sh), 993 (w), 949 (m), 930 (st), 896 (st), 845 (m), 801 (w), 750
(m, sh), 720 (m, sh)
7.7.7 Reaction of trans-dichloro bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with thallium
tetrakis (3,5-bis (trifluoromethyl)phenyl)borate in
methanol
A solution of trans-dichloro bis (1,2 bis (dimethylphosphino)ethane) ruthenium(II) (0.19 g, 0.40 mmol) and thallium tetrakis (3,5 bis (trifluoromethyl)phenyl)borate (0.56 g, 0.52 mmol) in methanol (20 mL) was stirred at 40 °C under a dinitrogen atmosphere for
14 hours. The resulting light green solution with fine white precipitate was filtered through celite and the filtrate evaporated to dryness in vacuo . The light green solid was washed with benzene (20 mL) and dried
to give trans [RuCl(dmpe) 2 ](BArF 2 4 ) (0.31 g, 20%).
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 198 K): δ P 39.6 (4P, b.s)
260 Chapter 7 Experimental
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 198 K): δ H 7.90 (8H, b.s,
Ar H o ), 7.76 (4H, b.s, Ar H p ), 1.75 (8H, b.s, PC H 2 CH 2 P), 1.43 (24H, b.s,
CH 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 437 ([RuCl(dmpe) 2 ] , 100%)
− − MS ( MALDI TOF): 863 ([B(C 6 H 3 (CF 3 ) 2 ) 4 ] , 100%)
ν IR m a x (ATR): 1611 (w), 1422 (w), 1354 (m, sh), 1274 (st), 1115 (st, b), 940
(m), 928 (m), 887 (m), 839 (m, sh), 742 (m), 710 (m, sh), 681 (m, sh), 669
(m, sh)
ν Raman selected : 2263 (w)
7.7.8 Reaction of trans-dichloro bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with thallium
tetrafluoroborate in methanol
A solution of trans-dichloro bis (1,2 bis (dimethylphosphino)ethane) ruthenium(II) (1.1 g, 2.3 mmol) and thallium tetrafluoroborate (0.60 g,
2.1 mmol) in methanol (20 mL) and diethyl ether (20 mL) was heated at reflux under nitrogen for one hour forming a yellow solution with copious white precipitate which was filtered through celite, during which the filtrate turned green. The filtrate was evaporated to dryness in vacuo and the residue washed with benzene (20 mL), then dried to give a light green
solid, trans [RuCl(BF 4 )(dmpe) 2 ] (0.032 g, 3%).
261 Chapter 7 Experimental
NOTE: substantial product was retained on the celite and was unrecoverable.
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 198 K): δ P 40.8 (4P, s)
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 198 K): δ H 1.74 (8H, b.s, C H 2 ),
1.43 (24H, b.s, C H 3 )
MS (+ MALDI TOF, C 6 0 matrix): 522 (unknown, +85, 100%), 568
(unknown, 58%)
ν IR m a x (ATR): 1634 (w, b), 1421 (m), 1284 (m), 1129 (m, b), 1058 (m, b),
928 (st), 891 (st), 841 (st), 796 (w), 738 (m), 707 (m), 678 (w)
7.7.9 Reaction of trans-dichloro bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with sodium
tetraphenylborate under high pressure dinitrogen in
methanol
Trans-dichloro bis (1,2 bis (dimethylphosphino)ethane)ruthenium(II) (0.74 g,
1.6 mmol) and sodium tetraphenylborate (0.53 g, 1.6 mmol) were added to the glass insert of a steel pressure vessel along with methanol
(20 mL). The vessel was charged with 140 psi dinitrogen gas and the vessel heated at 150 °C for 14 hours. The vessel was cooled and the pressure released. The previously yellow solution had decolourised and
262 Chapter 7 Experimental
deposited copious white solid. Both the solid and supernatant were
transferred under N 2 to a Schlenk flask and the solvent removed in vacuo to give a sparingly soluble white powder containing
trans-[RuCl(CO)(dmpe) 2 ](Cl) and trans-[Ru(H)(CO)(dmpe) 2 ](Cl) that dissolved in tetrahydrofuran to give a 3:1 ratio (0.95 g).
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran): δ P 39.4 (4P, s, trans-
[RuCl(CO)(dmpe) 2 ](Cl) (75%)), 34.1 (4P, s, trans-[Ru(H)(CO)(dmpe) 2 ](Cl)
(25%))
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): selected δ H 1.57 (8H, s,
trans-[Ru(H)(CO)(dmpe) 2 ](Cl), C H 2 ), 1.55 (8H, s, trans-
[RuCl(CO)(dmpe) 2 ](Cl), C H 2 ), 1.53 (24H, s, trans-[Ru(H)(CO)(dmpe) 2 ](Cl),
CH 3 ), 1.49 (24H, s, trans-[RuCl(CO)(dmpe) 2 ](Cl), C H 3 ), −9.46 (1H, s,
trans-[Ru(H)(CO)(dmpe) 2 ](Cl), Ru H)
ν ν ν IR m a x (ATR): 1957 (st, C O ), 1936 (st, C O ), 1580 (w), 1478 (m), 1416 (m),
1304 (w), 1288 (m, sh), 1268 (w), 1242 (w), 1146 (w, b), 1128 (w), 1082
(w), 1065 (w), 1032 (w), 996 (w, b), 941 (m), 928 (st), 893 (st, sh), 843 (m),
798 (m), 740 (m), 730 (st), 717 (m), 701 (st)
+ MS (+ MALDI TOF, C 6 0 matrix): 402 ([Ru(dmpe) 2 ] , 47%), 431
+ + ([Ru(H)(CO)(dmpe) 2 ] , 38%), 437 [RuCl(dmpe) 2 ] , 100%), 465
+ ([RuCl(CO)(dmpe) 2 ] , 57%)
263 Chapter 7 Experimental
7.7.10 Reaction of trans-dichloro bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with sodium
tetraphenylborate under high pressure dinitrogen in
tetrahydrofuran
Procedure as per the analogous reaction in methanol using tetrahydrofuran as the solvent resulted in a 2:3 ratio of
trans-[RuCl(CO)(dmpe) 2 ](Cl) to trans-[Ru(H)(CO)(dmpe) 2 ](Cl).
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran): δ P 39.4 (4P, s, trans-
[RuCl(CO)(dmpe) 2 ](Cl) (75%)), 34.1 (4P, s, trans-[Ru(H)(CO)(dmpe) 2 ](Cl)
(25%))
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): selected δ H 1.57 (8H, s,
trans-[Ru(H)(CO)(dmpe) 2 ](Cl), C H 2 ), 1.55 (8H, s, trans-
[RuCl(CO)(dmpe) 2 ](Cl), C H 2 ), 1.53 (24H, s, trans-[Ru(H)(CO)(dmpe) 2 ](Cl),
CH 3 ), 1.49 (24H, s, trans-[RuCl(CO)(dmpe) 2 ](Cl), C H 3 ), −9.46 (1H, s, trans-
[Ru(H)(CO)(dmpe) 2 ](Cl), Ru H)
ν ν ν IR m a x (ATR): 1957 (st, C O ), 1936 (st, C O ), 1580 (w), 1478 (m), 1416 (m),
1304 (w), 1288 (m, sh), 1268 (w), 1242 (w), 1146 (w, b), 1128 (w), 1082
(w), 1065 (w), 1032 (w), 996 (w, b), 941 (m), 928 (st), 893 (st, sh), 843 (m),
798 (m), 740 (m), 730 (st), 717 (m), 701 (st)
264 Chapter 7 Experimental
+ MS (+ MALDI TOF, C 6 0 matrix): 402 ([Ru(dmpe) 2 ] , 84%), 431
+ + ([Ru(H)(CO)(dmpe) 2 ] , 33%), 437 ([RuCl(dmpe) 2 ] , 100%), 465
+ ([RuCl(CO)(dmpe) 2 ] , 65%)
7.7.11 Reaction of cis-dichloro bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with trimethylsilyl
triflate in methanol
A solution of cis dichloro bis (1,2 bis (dimethylphosphino)ethane) ruthenium(II) (0.81 g, 1.7 mmol) and trimethylsilyl triflate (400 L,
2.2 mmol) in methanol (20 mL) was stirred under a dinitrogen atmosphere for 14 hours. The resulting pale green solution was evaporated to dryness in vacuo and the blue green solid washed with toluene (20 mL)
then dried to give a tacky blue green gum, cis [RuCl(OTf)(dmpe) 2 ] (0.75 g,
75%).
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 248 K): δ P 54.7 (1P, ddd,
2 2 2 2 J (AB) = 36.6, J (AC) = 16.7, J (AD) = 25.0, A), 54.1 (1P, ddd, J (BC) = 28.5,
2 2 J (BD) = 18.2, B), 43.6 (1P, ddd, J (CD) = −315.7, C), 35.5 (1P, ddd, D)
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 202 K): δ H 1.77 1.23 (32H, b.m)
+ MS (+ MALDI TOF, C 6 0 matrix): 437 ([RuCl(dmpe) 2 ] , 100%), 465
+ + ([RuCl(N 2 )(dmpe) 2 ] , 33%), 551 ([Ru(OTf)(dmpe) 2 ] , 26%)
265 Chapter 7 Experimental
MS ( − MALDI TOF): 149 (OTf, 100%)
ν IR m a x (ATR): 1421 (m), 1284 (sh, st), 1221 (st), 1155 (st), 1081 (w), 1026
(st), 929 (st), 894 (st), 837 (m), 799 (w), 732 (m), 704 (m)
7.7.12 Reaction of cis-dichloro bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with thallium
tetrakis (3,5-bis (trifluoromethyl)phenyl)borate in
methanol
A solution of thallium tetrakis (3,5 bis (trifluoromethyl)phenyl)borate
(0.55 g, 0.51 mmol) in methanol (10 mL) was added to a solution of cis-dichloro bis (1,2 bis (dimethylphosphino)ethane) ruthenium(II) (0.32 g,
0.67 mmol) in methanol (10 mL), forming an immediate white precipitate and a very pale yellow solution. The mixture was stirred for five minutes before filtering through celite. The filtrate was evaporated to dryness in vacuo and the residue washed with benzene (20 mL), then dried to give
an off white solid, cis [{RuCl(dmpe) 2 } 2 ( N 2 )](BArF 2 4 ) (0.39g, 71%).
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 248 K): 50.0 (1P, ddd,
2 2 2 2 J (AB) = 33.2, J (AC) = 15.7, J (AD) = 23.0, A), 44.7 (1P, ddd, J (BC) = 30.6,
2 2 J (BD) = 20.1, B), 40.2 (1P, ddd, J (CD) = −296.9, C), 37.4 (1P, ddd, D)
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 298 K): δ H 7.90 (16H, b.s,
Ar H o ), 7.77 (8H, b.s, Ar H p ), 2.17 1.29 (64H, b.m)
266 Chapter 7 Experimental
+ MS (+ MALDI TOF, C 6 0 matrix): 437 ([RuCl(dmpe) 2 ] , 100%)
ν IR m a x (ATR): 1611 (w), 1421 (w, b), 1354 (m), 1272 (st), 1159 (m), 1112
(st, b), 929 (m), 888 (m), 838 (m), 714 (m), 681 (m), 669 (m)
ν Raman selected : 2319 (w), 2284 (m)
7.7.13 Reaction of cis -dichloro bis (1,2-bis (dimethyl-
phosphino)ethane)ruthenium(II) with thallium
tetrafluoroborate in methanol
Cis-dichloro bis (1,2 bis (dimethylphosphino)ethane) ruthenium(II) (1.7 g,
3.5 mmol) and thallium tetrafluoroborate (0.92 g, 3.1 mmol) in methanol
(25 mL) were heated at reflux under nitrogen for two hours forming a yellow solution with copious white precipitate. The mixture was filtered through celite to give a clear light green filtrate. The filtrate was evaporated to dryness in vacuo and the residue washed with benzene
(20 mL), then dried to give a light green solid, cis [RuCl(BF 4 )(dmpe) 2 ]
(0.72 g, 38%).
NOTE: some product was retained on the celite and was unrecoverable.
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 248 K): δ P 54.7 (1P, ddd,
2 2 2 2 J (AB) = 14.3, J (AC) = 19.7, J (AD) = 25.7, A), 54.6 (1P, ddd, J (BC) = 23.9,
2 2 J (BD) = 19.8, B), 43.8 (1P, ddd, J (CD) = −315.5, D), 35.9 (1P, ddd, C)
267 Chapter 7 Experimental
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 202 K): δ H 2.31 1.20 (b.m)
+ MS (+ MALDI TOF, C 6 0 matrix): 437 ([RuCl(dmpe) 2 ] , 100%)
ν IR m a x (ATR): 1626 (w, b), 1418 (m), 1301 (m), 1282 (m), 1241 (w), 1049
(st), 926 (st), 892 (st), 836 (st), 734 (m), 702 (st)
7.7.14 Reaction of trans -dichloro bis (1,2-bis (diethyl-
phosphino)ethane)ruthenium(II) with trimethylsilyl
triflate in toluene
Trimethylsilyl triflate (100 L, 0.55 mmol) was added to a solution of trans-dichloro bis (1,2 bis (diethylphosphino)ethane)ruthenium(II) (0.32 g,
0.54 mmol) in toluene ( ca. 40 mL). The reaction mixture was stirred at room temperature for 14 hours, during which time the initially yellow solution formed a red oil which redissolved and eventually gave a teal blue solid and a yellow solution. The solid was collected on a sintered glass frit, washed with toluene (30 mL) and pentane (2 x 30 mL) then
I I I dried to give [Ru Cl 2 (depe) 2 ](OTf) (0.31 g, 78%).
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): 1.58 (24H, b.s, CH 2 CH 3 ),
−9.66 (8H, b.s, PC H 2 CH 2 P), −13.16 (16H, b.s, PC H 2 CH 3 )
ν IR m a x (ATR): 1060 (m), 1415 (m), 1324 (m), 1299 (m), 1279 (m), 1222 (st),
1167 (st), 1022 (st), 874 (m), 820 (m), 761 (st), 735 (st)
268 Chapter 7 Experimental
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%), 574
+ ([RuCl 2 (depe) 2 ] , 53%)
7.7.15 Reaction of trans -dichloro bis (1,2-bis (diethyl-
phosphino)ethane)ruthenium(II) with thallium
triflate in tetrahydrofuran
A solution of trans-dichloro bis (1,2 bis (diethylphosphino)ethane) ruthenium(II) (0.82 g, 1.4 mmol) and thallium triflate (0.50 g, 1.4 mmol) in tetrahydrofuran (50 mL) was heated at reflux for 14 hours, during which time a white precipitate formed. The orange/brown solution was cooled to room temperature, during which the colour changed a number of times (yellow dark green). The cooled reaction mixture was filtered, and the filtrate evaporated to dryness in vacuo to give a dark green solid,
cis [{Ru(depe) 2 } 2 ( Cl) 2 ](OTf) 2 (1.6 g, 82%).
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran, 180 K): δ P 62.1 (2P, app. b.t,
splitting = 21.9, P equatorial ), 45.9 (2P, app. b.t, P axial )
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran, 180 K): δ H 2.66 1.39 (24H,
b.m, C H 2 ), 1.39 0.97 (24H, b.m, C H 3 )
ν IR m a x (ATR): 1461 (m), 1415 (m), 1383 (w), 1244 (st), 1223 (st, sh), 1152
(st), 1079 (m, b), 1027 (st, sh), 871 (w), 818 (w), 757 (m), 734 (m)
269 Chapter 7 Experimental
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%), 584
+ + ([RuCl 2 (depe) 2 ] , 40%), 1098 ([Ru 2 Cl 2 (depe) 4 ] , 6%)
7.7.16 Reaction of trans-dichloro bis (1,2-(bis (diethyl-
phosphino)ethane)ruthenium(II) with trimethylsilyl
triflate in methanol
A solution of trans-dichloro bis (1,2 bis (diethylphosphino)ethane) ruthenium(II) (0.076 g, 0.13 mmol) in methanol (20 mL) was stirred under a dinitrogen atmosphere for 20 minutes before trimethylsilyl triflate
(52 L, 0.29 mmol) was added and the mixture stirred for 14 hours. The resulting teal/green solution was evaporated to dryness in vacuo and the green solid washed with cold benzene (20 mL) to give
cis [{Ru(depe) 2 } 2 ( Cl) 2 ](OTf) 2 (0.040 g, 44%).
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran, 180 K): δ P 62.1 (2P, app. b.t,
splitting = 21.9, P equatorial ), 45.9 (2P, app. b.t, P axial )
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran, 180 K): δ H 2.66 1.39 (24H,
b.m, C H 2 ), 1.39 0.97 (24H, b.m, C H 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%), 584
+ ([RuCl 2 (depe) 2 ] , 39%)
ν IR m a x (ATR): 1456 (m, b), 1416 (m, b), 1379 (w), 1260 (st), 1221 (m, sh),
1137 (m, b), 1027 (st, sh), 984 (w), 873 (m), 825 (m), 736 (m, b)
270 Chapter 7 Experimental
7.7.17 Reaction of trans -dichloro bis (1,2-bis (diethyl-
phosphino)ethane)ruthenium(II) with silver triflate
in methanol
A solution of trans-dichloro bis (1,2 bis (diethylphosphino)ethane) ruthenium(II) (0.24 g, 0.41 mmol) and silver triflate (0.11 g, 0.41 mmol) in methanol (20 mL) was heated at reflux under a dinitrogen atmosphere for
14 hours. The resulting yellow solution with fine grey precipitate was filtered and the filtrate evaporated to dryness in vacuo . The yellow solid was washed with benzene (20 mL) and dried to give
cis [{Ru(depe) 2 } 2 ( Cl) 2 ](OTf) 2 (AgCl) 2 , which turned dark green over time when stored under nitrogen (0.15 g, 43%).
3 1 1 P{ H} NMR (121 MHz, CDCl 3 , 248 K): δ P 61.8 (2P, app. t,
3 splitting = 22.2, P equatorial ), 44.9 (2P, app. dt, J (P X) = 8.1, P axial )
1 3 1 H{ P} NMR (300 MHz, CDCl 3 , 248 K): δ H 2.53 1.26 (24H, b.m, C H 2 ),
1.23 0.95 (24H, m, C H 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%), 1098
([Ru 2 Cl 2 (depe) 4 ](OTf) 2 , 5%)
ν IR m a x (KBr): 1635 (m, b), 1458 (m), 1418 (m), 1274 (st, b), 1221 (m, sh),
1144 (m), 1077 (m), 1031 (st, sh), 870 (m, sh), 817 (m), 759 (m), 726 (m),
669 (st, sh), 636 (st, sh), 570 (m, sh), 516 (m, sh)
271 Chapter 7 Experimental
7.7.18 Reaction of trans-dichloro bis (1,2-bis (diethyl-
phosphino)ethane)ruthenium(II) with thallium
tetrakis (3,5-bis (trifluoromethyl)phenyl)borate in
methanol
A solution of trans-dichloro bis (1,2 bis (diethylphosphino)ethane) ruthenium(II) (0.30 g, 0.52 mmol) and thallium tetrakis (3,5 bis (trifluoromethyl)phenyl)borate (0.56 g, 0.52 mmol) in methanol (20 mL) was stirred under a dinitrogen atmosphere for
14 hours. The resulting pale yellow solution with fine white precipitate was filtered through celite and the filtrate evaporated to dryness in vacuo . The pale yellow solid was washed with benzene (20 mL) and
dried to give cis [{Ru(Cl)(depe) 2 } 2 ( N 2 )](BArF 2 4 ) 2 (0.35 g, 48%).
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 248 K): δ P 64.4 (1P, ddd,
2 2 2 2 J (AB) = 31.7, J (AC) = 15.4, J (AD) = 21.5, A), 53.9 (1P, ddd, J (BC) = 28.7,
2 2 J (BD) = 19.9, B), 51.2 (1P, ddd, J (CD) = −277.2, C), 49.1 (1P, ddd, D)
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 202 K): δ H 7.89 (16H, s,
Ar H o ), 7.77 (8H, s, Ar H p ), 2.39 1.39 (48H, b.m, C H 2 ), 1.39 0.98 (48H,
b.m, C H 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%)
272 Chapter 7 Experimental
ν IR m a x (ATR): 1610 (w), 1463 (w, b), 1419 (w, b), 1354 (m, sh), 1272 (st),
1112 (st, b), 1031 (m, b), 933 (w), 886 (m), 839 (m, sh), 819 (w), 761 (w),
743 (m), 712 (m, sh), 681 (m, sh), 669 (m, sh)
ν Raman selected : 2280 (m)
7.7.19 Reaction of trans-dichloro bis (1,2-bis (diethyl-
phosphino)ethane)ruthenium(II) with thallium
tetrafluoroborate in methanol
A solution of trans-dichloro bis (1,2 bis (diethylphosphino)ethane) ruthenium(II) (0.51 g, 0.87 mmol) and thallium tetrafluoroborate (0.24 g,
0.84 mmol) in methanol (20 mL) and diethyl ether (20 mL) was heated at reflux under nitrogen for one hour forming a yellow solution with copious white precipitate which was filtered through celite, during which the filtrate turned green. The filtrate was evaporated to dryness in vacuo and the residues washed with benzene (20 mL), then dried to give a dark
green solid, cis [RuCl(BF 4 )(depe) 2 ] (0.086 g, 16%).
NOTE: substantial product was retained on the celite and was unrecoverable.
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 248 K): δ P 66.7 (2P, app. t, splitting = 21.5, A+B ), 50.2 (1P, app. dt, splitting = 21.3,
2 J (CD) = −294.3, C), 48.0 (1P, app. dt, splitting = 21.3, D)
273 Chapter 7 Experimental
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 248 K): δ H 2.48 1.35 (24H,
b.m, C H 2 ), 1.35 0.98 (24H, b.m, C H 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%), 577
+ ([RuCl(N 2 )(depe) 2 ] , 54%), 634 (unknown, 71%)
ν IR m a x (ATR): 2126 (m, b, ν N N ), 1945 (w, b), 1620 (m), 1460 (m), 1416 (m),
1382 (w), 1280 (w), 1252 (w), 1027 (st), 872 (m), 819 (m), 758 (st), 732
(st)
7.7.20 Reaction of cis-dichloro bis (1,2-bis (diethyl-
phosphino)ethane)ruthenium(II) with trimethylsilyl
triflate in methanol
A solution of cis-dichloro bis (1,2 bis (diethylphosphino)ethane) ruthenium(II) (0.95 g, 1.6 mmol) and trimethylsilyl triflate (400 L,
2.2 mmol) in methanol (20 mL) was stirred under a dinitrogen atmosphere for 14 hours. The resulting dark blue solution was evaporated to dryness in vacuo . The blue green residue was washed with toluene (40 mL) and
I I I dried to give a dark blue solid, trans [Ru Cl 2 (depe) 2 ](OTf) (1.2 g, 100%).
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 298 K): δ H 1.58 (24H, b.s,
CH 2 CH 3 ), −9.66 (8H, b.s, PC H 2 CH 2 P), −13.16 (16H, b.s, PC H 2 CH 3 )
274 Chapter 7 Experimental
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%), 574
+ ([RuCl 2 (depe) 2 ] , 68%), 1098 ([Ru 2 Cl 2 (depe) 4 ](OTf) 2 , 3%)
MS ( − MALDI TOF): 149 (OTf, 100%)
ν IR m a x (ATR): 1460 (m), 1415 (m), 1324 (m), 1299 (m), 1279 (m), 1222 (st),
1167 (st), 1022 (st), 874 (m), 820 (m), 761 (st), 735 (st)
7.7.21 Reaction of cis-dichloro bis (1,2-bis (diethyl-
phosphino)ethane)ruthenium(II) with thallium
tetrakis (3,5-bis (trifluoromethyl)phenyl)borate in
methanol
A solution of thallium tetrakis (3,5 bis (trifluoromethyl)phenyl)borate
(0.48 g, 0.44 mmol) in methanol (10 mL) was added to a solution of cis-dichloro bis (1,2 bis (diethylphosphino)ethane)ruthenium(II) (0.28 g,
0.48 mmol) in methanol (10 mL), forming an immediate white precipitate and a yellow solution. The mixture was stirred for five minutes before filtering through celite. The filtrate was evaporated to dryness in vacuo and the residue washed with benzene (20 mL), then dried to give
cis [{RuCl(depe) 2 } 2 )(N 2 )](BArF 2 4 ) 2 (0.31g, 45%).
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 248 K): 64.4 (1P, ddd,
2 2 2 2 J (AB) = 33.2, J (AC) = 15.7, J (AD) = 23.0, A), 53.9 (1P, ddd, J (BC) = 30.6,
2 2 J (BD) = 20.1, B), 51.1 (1P, ddd, J (CD) = −296.9, C), 49.2 (1P, ddd, D) 275 Chapter 7 Experimental
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 298 K): δ H 7.78 (16H, b.s,
Ar H o ), 7.57 (8H, b.s, Ar H p ), 2.64 1.35 (48H, m, C H 2 ), 1.35 1.01 (48H, m,
CH 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%)
ν IR m a x (ATR): 1610 (w), 1463 (w), 1420 (w), 1353 (m), 1272 (st), 1114 (st),
1032 (m, b), 934 (m, b), 839 (m), 712 (m), 681 (m), 670 (m)
ν Raman selected : 2280
7.7.22 Reaction of cis -dichloro bis (1,2-bis (diethyl-
phosphino)ethane)ruthenium(II) with thallium
tetrafluoroborate in methanol
Cis-dichloro bis (1,2 bis (diethylphosphino)ethane)ruthenium(II) (2.7 g,
4.5 mmol) and thallium tetrafluoroborate (1.2 g, 4.2 mmol) in methanol
(25 mL) were heated at reflux under nitrogen for two hours forming a red solution with copious white precipitate. The mixture was filtered through celite to give a clear red filtrate. The filtrate was evaporated to dryness in vacuo and the residue washed with benzene (20 mL), then dried to give
a brick red solid film, cis [RuCl(BF 4 )(depe) 2 ] (1.83 g, 62%).
NOTE: some product was retained on the celite and was unrecoverable.
276 Chapter 7 Experimental
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 198 K): δ P 66.2 (1P, ddd,
2 2 2 2 J (AB) = 33.5, J (AC) = 19.3, J (AD) = 21.5, A), 65.4 (1P, ddd, J (BC) = 26.4,
2 2 J (BD) = 20.9, B), 48.8 (1P, ddd, J (CD) = −295.5, C), 47.1 (1P, ddd, D)
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 198 K): δ H 2.50 1.38 (24H,
b.m, C H 2 ), 1.38 0.94 (24H, b.m, C H 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%)
ν IR m a x (ATR): 1618 (w, b), 1506 (w), 1460 (m), 1418 (m), 1381 (w), 1250
(w), 1028 (st), 872 (m), 818 (m), 760 (m), 734 (m)
7.8 Reactions of trans -dichloro bis (1,2-bis (dimethyl- phosphino)ethane)ruthenium, thallium triflate
7.8.1 Reaction of trans-dichloro bis (1,2 -bis (dimethyl-
phosphino)ethane)ruthenium(II), thallium triflate
with sodium tetraphenylborate
Sodium tetraphenylborate (0.33 g, 0.96 mmol) was added to a solution of trans-dichloro bis (1,2 bis (dimethylphosphino)ethane)ruthenium(II), thallium triflate (0.45 g, 0.54 mmol) in ethanol (40 mL). The reaction mixture was stirred for one hour, with a cream coloured precipitate forming immediately. The solid was isolated by filtration and washed with ethanol (10 mL) and pentane (10 mL), then dried. NMR and MALDI MS spectra are very complicated, with numerous species present. The IR
277 Chapter 7 Experimental
spectrum shows a very weak dinitrogen stretch. Similar results were obtained when sodium tetrafluoroborate was used in place of sodium tetraphenylborate.
ν IR selected (KBr): 2131 (w, ν N N )
7.8.2 Reaction of trans-dichloro bis (1,2 -bis (dimethyl-
phosphino)ethane)ruthenium(II), thallium triflate
with sodium tetrakis (3,5-bis (trifluoromethyl)-
phenyl)borate
Trans-dichloro bis (1,2 bis (dimethylphosphino)ethane)ruthenium(II), thallium triflate (0.10 g, 0.12 mmol) and sodium tetrakis (3,5 bis (trifluoromethyl)phenyl)borate (0.20 g, 0.16 mmol) were dissolved in methanol (30 mL) and stirred for 14 hours, during which time the initially light green solution rapidly turned yellow. The mixture was filtered through celite and the filtrate evaporated to dryness in vacuo . The yellow residue was washed with benzene (20 mL) and pentane (2 x 10 mL)
then dried to give trans-[RuCl(N 2 )(dmpe) 2 ](BArF 2 4 ) (0.19 g, 102%).
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran): δ P 39.0 (4P, s)
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): δ H 7.73 (8H, s, Ar H o ), 7.50
(4H, s, Ar H p ), 1.71 (8H, s, C H 2 ), 1.38 (24H, s, C H 3 )
278 Chapter 7 Experimental
+ MS (+ MALDI TOF, C 6 0 matrix): 437 ([RuCl(dmpe) 2 ] , 100%), 465
+ ([RuCl(N 2 )(dmpe) 2 ] , 40%)
IR ν (KBr): 2012 (m, ν ), 1611 (m, sh), 1423 (m, sh), 1356 (st, sh), m a x N 2
1277 (st, b), 1164 (st, b), 1121 (st, b), 1049 (m), 1036 (m), 941 (m), 930
(m), 889 (m), 839 (m, sh), 795 (w), 745 (w), 714 (m), 692 (w), 683 (m, sh),
669 (m), 648 (m, b), 577 (w, b), 515 (w, b), 453 (w, b)
7.8.3 Reaction of trans-dichloro bis (1,2 -bis (dimethyl-
phosphino)ethane)ruthenium(II), thallium triflate
with hydrazine
Hydrazine solution (1M in tetrahydrofuran, 240 L, 0.24 mmol) was added to a solution of trans-dichloro bis (1,2 bis (dimethylphosphino)ethane) ruthenium(II), thallium triflate (0.13 g, 0.16 mmol) in tetrahydrofuran
(20 mL) and the mixture stirred at room temperature for 14 hours. The mixture was filtered through celite and the filtrate evaporated to dryness
in vacuo , giving a dark yellow solid, trans [RuCl(H 2 NNH 2 )(dmpe) 2 ](OTf).
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran): δ P 37.3 (4P, s)
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): δ H 4.76 (2H, s), 4.12 (2H, s),
1.77 (8H, s, C H 2 ), 1.44 (24H, s, C H 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 437 ([RuCl(dmpe) 2 ] , 100%)
279 Chapter 7 Experimental
ν IR m a x (KBr): 3327 (m, b), 3277 (m, b), 3200 (m, b), 1420 (st, sh), 1277
(st, b), 1234 (st, b), 1159 (st, b), 1078 (w), 1024 (st), 989 (w), 941 (st),
930 (st), 893 (st, sh), 797 (m), 739 (m), 708 (st, sh), 636 (st, sh), 573 (m),
515 (m, sh), 455 (m)
7.8.4 Reaction of trans-dichloro bis (1,2 -bis (dimethyl-
phosphino)ethane)ruthenium(II), thallium triflate
with ammonia
Ammonia solution (1M in EtOH, 320 L, 0.32 mmol) was added to a solution of trans-dichloro bis (1,2 bis (dimethylphosphino)ethane) ruthenium(II), thallium triflate (0.17 g, 0.21 mmol) in tetrahydrofuran
(20 mL) and the mixture stirred at room temperature for 14 hours. The mixture was filtered through celite and the filtrate evaporated to dryness
in vacuo , giving a light yellow solid, trans [RuCl(NH 3 )(dmpe) 2 ](OTf).
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran): δ P 39.3 (4P, s)
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): δ H 2.54 (3H, s, N H 3 ), 1.69
(8H, s, C H 2 ), 1.35 (24H, s, C H 3 )
1 5 1 1 N H HSQC NMR (41 MHz, d 8 tetrahydrofuran): δ N −35 (correlates to H at 2.54)
+ MS (+ MALDI TOF, C 6 0 matrix): 437 ([RuCl(dmpe) 2 ] , 100%)
280 Chapter 7 Experimental
ν IR m a x (KBr): 3339 (m, b), 3209 (w, b), 1420 (m, sh), 1279 (st), 1232 (st),
1159 (m), 1078 (w), 1024 (st, sh), 987 (w), 941 (st), 929 (m), 891 (m, sh),
839 (m, sh), 797 (w), 739 (m), 708 (m), 636 (st, sh), 573 (w), 517 (w, sh),
457 (w)
7.9 Reactions of di-µ-chloro tetrakis (1,2-
bis (diethylphosphino)ethane)diruthenium(II)
ditriflate
7.9.1 Reaction of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 with carbon
monoxide
A solution of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 ( ca. 10 mg, 0.0072 mmol) in deuterated tetrahydrofuran ( ca. 1 mL) was degassed by three freeze pump thaw cycles and exposed to 1 atm of carbon monoxide for one hour. 3 1 P NMR shows complete conversion of starting material to
cis [RuCl(CO)(depe) 2 ](OTf).
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran): δ P 56.6 (1P, ddd,
2 2 2 J (AB) = 29.3, J (AC) = 11.9, J (AD) = 18.7, A) 52.1 (1P, distorted ddd,
2 2 2 J (BC) = 30.6, J (BD) = 23.0, D), 49.1 (1P, distorted ddd, J (CD) = −234.8, C),
32.4 (1P, ddd, B)
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): δ H 2.40 0.66 (m)
1 3 1 3 1 C{ H, P} NMR (101 MHz, d 8 tetrahydrofuran): selected δ C 201.1 (Ru
CO)
281 Chapter 7 Experimental
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%), 577
+ ([RuCl(CO)(depe) 2 ] , 60%)
IR ν (KBr): 1983 (st, ν ) 1271 (st, ν ), 1265 (st, ν + δ ) m a x C O S O 3 S O 3
7.9.2 Reaction of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 with acetonitrile
Acetonitrile (10 L, 0.19 mmol) was added to a solution of
[Ru 2 Cl 2 (depe) 4 ](OTf) 2 ( ca. 10 mg, 0.0072 mmol) in deuterated tetrahydrofuran ( ca. 1 mL). The reaction mixture was shaken for one minute, then left to react for one hour. The initial dark green solution rapidly turned a light blue green with formation of a white precipitate.
3 1 P NMR shows complete conversion of starting material to
2 7 cis [RuCl(NCMe)(depe) 2 ](OTf).
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 298 K): δ P 62.7 (1P, ddd,
2 2 2 2 J (AB) = 31.2, J (AC) = 16.6, J (AD) = 21.4, A) 53.91 (1P, ddd, J (BC) = 27.3,
2 2 J (BD) = 20.7, B), 49.2 (1P, app. dd, J (CD) = −198.4, C), 48.7 (1P, app. t,
D)
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 298 K): δ H 2.46 (3H, s,
NC Me ), 2.36 1.01 (m)
+ MS (+ MALDI TOF, C 6 0 matrix): 540 ([Ru(CN)(depe) 2 ] , 26%), 549
+ ([RuCl(depe) 2 ] , 100%)
282 Chapter 7 Experimental
7.9.3 Reaction of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 with tert -butyl
isonitrile
Tert butyl isonitrile (10 L, 0.088 mmol) was added to a solution of
[Ru 2 Cl 2 (depe) 4 ](OTf) 2 ( ca. 10 mg, 0.0072 mmol) in deuterated tetrahydrofuran ( ca. 1 mL). The reaction mixture was shaken for one minute, then left to react for one hour. The initial dark green solution rapidly turned a light green with formation of a white precipitate. The 3 1 P
NMR spectrum shows complete conversion of starting material to
t cis [RuCl(CN Bu)(depe) 2 ](OTf).
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran): δ P 60.4 (1P, ddd,
2 2 2 2 J (AB) = 27.2, J (AC) = 16.7, J (AD) = 19.2, A) 50.6 (1P, ddd, J (BC) = 29.2,
2 2 J (BD) = 21.7, D), 49.6 (1P, ddd, J (CD) = −234.3, C), 37.6 (1P, ddd, B)
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): δ H 2.35 1.41 (24H, m, PC H 2 ),
t 1.53 (9H, s, Bu), 1.36 1.02 (24H, m, PC H 3 )
1 3 1 3 1 C{ H, P} NMR (101 MHz, d 8 tetrahydrofuran): selected δ C 149.4
t (Ru CN Bu), 57.9 ( C(CH 3 ) 3 ), 30.4 (C(CH 3 ) 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 540 ([Ru(CN)(depe) 2 ] , 32%), 549
+ + ([RuCl(depe) 2 ] , 100%), 561 ([RuCl(C)(depe) 2 ] , 19%), 632
t + ([RuCl(CN Bu)(depe) 2 ] , 32%)
IR ν (KBr): 2139 (st, ν ) 1273 (st, ν ), 1265 (st, ν + δ ) selected N C S O 3 S O 3
283 Chapter 7 Experimental
1 5 7.9.4 Reaction of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 with N-
ammonia
A solution of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 (50 mg, 0.036 mmol) in deuterated tetrahydrofuran ( ca. 1 mL) was degassed by three freeze pump thaw cycles and an excess of 98% 1 5 N ammonia was condensed in by vacuum transfer. Upon thawing a white precipitate formed immediately. The
1 5 sample was left under NH 3 for 14 hours then filtered to give a clear
1 5 violet solution of cis [RuCl( NH 3 )(depe) 2 ](OTf).
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 298 K): δ P 64.8 (1P, ddd,
2 2 2 2 J (AB) = 30.3, J (AC) = 17.9, J (AD) = 25.3, A) 56.5 (1P, ddd, J (BC) = 24.9,
2 J = 18.2, 2 J = 25.8, B), 48.7 (1P, ddd, 2 J = −285.0, D), 46.8 (BD) ( P N trans ) (CD)
(1P, ddd, C)
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 298 K): δ H 2.48 (3H, d,
1 J (HN) = 68.1, Ru NH 3 ), 2.51 1.46 (24H, m, C H 2 ), 1.29 1.05 (24H, m, C H 3 )
1 5 1 N{ H} NMR (51 MHz, d 8 tetrahydrofuran, 298 K): δ N −29.3 (1N, d,
2 J = 25.1) ( N P trans )
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%), 567
1 5 + ([RuCl( NH 3 )(depe) 2 ] , <1%)
284 Chapter 7 Experimental
ν IR m a x (ATR): 3316 (m, b), 1579 (m, b), 1458 (m), 1414 (m), 1385 (w),
1255 (st), 1223 (m, sh), 1146 (st), 1100 (st), 1029 (st, sh), 875 (w), 818
(w), 754 (m), 733 (m)
7.9.5 Reaction of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 with hydrazine
Hydrazine solution (1 M in tetrahydrofuran, 100 L, 0.1 mmol) was added
to a solution of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 ( ca. 10 mg, 0.0072 mmol) in deuterated tetrahydrofuran ( ca. 1 mL). The reaction mixture was shaken for one minute, then left to react for one hour. The initial dark green solution rapidly turned yellow with formation of a white precipitate. 3 1 P
NMR shows complete conversion of starting material to
cis [RuCl(NH 2 NH 2 )(depe) 2 ](OTf). After three hours the sample had darkened to amber and began precipitating an orange insoluble polymeric solid.
3 1 1 P{ H} NMR (162 MHz, d 8 tetrahydrofuran): δ P 62.2 (1P, ddd,
2 2 2 2 J (AB) = 30.2, J (AC) = 19.5, J (AD) = 20.2, A) 54.3 (1P, ddd, J (BC) = 25.5,
2 2 J (BD) = 21.0, B), 47.1 (1P, ddd, J (CD) = −284.7, C), 46.5 (1P, ddd, D)
1 3 1 H{ P} NMR (400 MHz, d 8 tetrahydrofuran): δ H 3.32 (2H, b.s,
Ru NH 2 NH 2 ), 2.55 (2H, b.s, Ru NH 2 ), 2.40 1.03 (48H, m, C H 2 /C H 3 )
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%)
285 Chapter 7 Experimental
7.9.6 Reaction of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 with hydrogen
A solution of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 (0.57 g, 0.41 mmol) in tetrahydrofuran
(50 mL) was stirred under 1 atm of hydrogen gas. The initial dark green solution rapidly lightened in colour and formed a white precipitate. After stirring under a static atmosphere of hydrogen for 14 hours the mixture was filtered to afford a clear yellow solution. The filtrate was evaporated
η 2 to dryness in vacuo to give a solid yellow film, [RuCl( H 2 )(depe) 2 ](OTf)
(0.39 g, 68%). 2 8
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 298 K): δ P 54.0 (4P, s)
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 298 K): δ H 2.50 1.75 (24H, m,
CH 2 ), 1.24 1.06 (24H, m, C H 3 ), −14.26 (2H, s, Ru H 2 )
+ MS (+ MALDI TOF, C 6 0 matrix): 514 ([Ru(depe) 2 ] , 89%), 549
+ ([RuCl(depe) 2 ] , 100%)
7.9.7 Reaction of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 with high
pressure dinitrogen
A solution of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 (0.24 g, 0.17 mmol) in tetrahydrofuran
(10 mL) was placed inside the glass insert of a steel pressure vessel. The vessel was charged with 140 psi dinitrogen gas and heated at 140 °C for
48 hours. The vessel was cooled and the pressure released. The previously dark green solution had decolourised and formed a white
286 Chapter 7 Experimental
crystalline precipitate. The mixture was filtered through filter paper
under N 2 into a Schlenk flask, and the filtrate evaporated to dryness in vacuo to give a white solid, trans [RuCl(CO)(depe) 2 ](OTf) (0.18 g, 72%).
3 1 1 P{ H} NMR (202 MHz, tetrahydrofuran/ d 8 tetrahydrofuran, 298 K): δ P
46.4 (4P, s)
1 3 1 H{ P} NMR (500 MHz, tetrahydrofuran/ d 8 tetrahydrofuran, 298 K): δ H
3 3 2.43 (4H, hex., J (HH) = 7.7, C H 2 ), 2.23 (4H, hex., J (HH) = 7.6, C H 2 ),
3 2.11 1.84 (12H, m, C H 2 ), 1.63 (4H, m, C H 2 ), 1.25 (12H, t, J (HH) = 7.6,
3 CH 3 ), 1.19 (12H, t, J (HH) = 7.7, C H 3 )
ν ν IR m a x (ATR): 1938 (st, C O ), 1767 (w, b), 1744 (w, b), 1458 (m), 1417 (m),
1381 (w), 1258 (st), 1221 (st, sh), 1149 (st, sh), 1099 (w), 1025 (st, sh),
988 (m), 874 (m), 822 (m), 738 (st), 709 (m), 678 (m)
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 67%), 577
+ ([RuCl(CO)(depe) 2 ] , 100%)
7.9.8 Reaction of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 with CO 2 ,
H 2 CCH 2 , and N 2 O
Solutions of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 in deuterated tetrahydrofuran failed to react with 1 atm of the following gases: carbon dioxide, ethylene and nitrous oxide. Heating the samples at 60˚C had no effect.
287 Chapter 7 Experimental
7.9.9 Reaction of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 with sodium
tetraphenylborate
Sodium tetraphenylborate (0.47 g, 1.4 mmol) was added to a solution of
[Ru 2 Cl 2 (depe) 4 ](OTf) 2 (1.0 g, 0.73 mmol) in ethanol (40 mL) and the mixture stirred for one hour. A cream coloured precipitate formed immediately. The reaction mixture was filtered and the solid residue washed with 10 mL of ethanol then dried (1.3g).
NOTE: The 3 1 P NMR spectrum shows multiple (> 8) species, although the
IR spectrum shows a single stretch in the dinitrogen stretching region.
IR ν (KBr): 2140 (st, ν ) selected N 2
7.9.10 Reaction of [Ru 2 Cl 2 (depe) 4 ](OTf) 2 with sodium
azide
Sodium azide (20 mg, 0.31 mmol) was added to a solution of
[Ru 2 Cl 2 (depe) 4 ](OTf) 2 ( ca. 10 mg, 0.0072 mmol) in deuterated tetrahydrofuran ( ca. 1 mL). The reaction mixture was shaken for one minute, then left to react for one hour. The initial dark green solution rapidly turned a dirty yellow with formation of a white precipitate. The
3 1 P NMR spectrum shows complete conversion of starting material,
affording cis [RuCl(N 3 )(depe) 2 ](OTf).
288 Chapter 7 Experimental
NOTE: Accurate determination of coupling constants by simulation was unsuccessful
3 1 1 P{ H} NMR (202 MHz, d 8 tetrahydrofuran, 298 K): δ P 64.6 (1P, ddd, A),
60.5 (1P, ddd, B), 50.5 (2P, unresolved 2 x ddd, C+D)
1 3 1 H{ P} NMR (500 MHz, d 8 tetrahydrofuran, 298 K): δ H 2.35 0.98 (m)
+ MS (+ MALDI TOF, C 6 0 matrix): 549 ([RuCl(depe) 2 ] , 100%)
ν IR selected (KBr): 2104 (m), 2043 (m), 1945 (w, b), 1832 (w, b)
289 Chapter 7 Experimental
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