N-Functionalization of the Tetrahedrane Fe2(CO)6(/z-SNH) Max Herberhold*, Uw e Bertholdt, Wolfgang M ilius, Bernd Wrackmeyer Laboratorium für Anorganische Chemie, Universität Bayreuth, D-95440 Bayreuth Dedicated to Prof. Dr. Lothar Beyer on the occasion of his 60th birthday Z. Naturforsch. 51 b, 1283-1289 (1996); received March 27, 1996 Azadiferrathia, Tetrahedrane, Cluster Anion, Element-Nitrogen Bonds, NMR Spectra The azadiferrathia tetrahedrane, Fe 2(CO)6(£/-SNH) (1), was deprotonated to give the anion [Fe2(CO)6(/J-SN)]_ (2) which reacts with halides of phosphorus, arsenic, silicon, germanium, tin and boron by formation of element-nitrosen bonds. The new compounds were characterized by their IR. NMR('H, mB, i3C, i5N, 29Si,3 P, m Sn)and mass spectra. The molecular structure of [Fe2(CO)6(A/-SN-SiMe2CH 2-)]2 (11) was determined by X-ray structure analysis (space group Pi; triclinic; a = 799.8(2), b = 958.5(2), c = 1035.7(2) pm, a = 86.30(2)°, (3 = 81.27(2)°, 7 = 69.90(2)°). Introduction Results and Discussion The reaction of carbonyliron complexes with Syntheses bis(trimethylsilyl)sulfurdiimide, The reactions of the anion 2 with various element Me3Si(NSN)SiMe3, followed by chromatography halides are summarized in Scheme 1. Apparently, on silica, leads to the azadiferrathia tetrahedrane any triorganosilyl, -germyl or -stannyl chloride can 1 [1]. The corresponding anion 2 is formed by be used to prepare complexes of the type 3-5. The deprotonation using sodium [2], "BuLi in hex­ reactions of 2 with bis(chlorosilyl) compounds, as ane or DBU (l,8-diazabicyclo[5.4.0]undec-7-ene) shown in Scheme 2, afford the new compounds 9 [3] [eq. (1)]. It was already shown that 2 reacts - 11, of which 11 was studied by X-ray diffraction with Me^'BuSiCl to give the N-silylated complex (vide infra). Fe2(CO)6(//-SN-SiMe2'Bu) [2], and that N-organo- It appears that the reaction of 2 with arsenic chlo­ substituted derivatives Fe 2(CO)6(/u-SN-R) are ac­ rides is also straightforward, and the products 6a and cessible from the reaction of 2 with carbenium or 6b are isolated in moderate to good yields. In con­ trialkyl oxonium cations [3], These successful trans­ trast, 'BU2PCI does not react with 2. If the reaction formations of 2 prompted us to start a systematic of 2 with either 'PnPCl or Cy 2PCl is monitored by study of the N-functionalization of 1. Here we de­ IR spectroscopy , the presence of the desired prod­ scribe the new complexes which contain group 15 ucts can be observed for about 5 - 1 0 min at -78°C, (phosphanyl, arsanyl), group 14 (silyl, germyl. stan- but thereafter decomposition into unidentified com­ nyl) and group 13 (boryl) substituents at the nitrogen pounds takes place, as is also apparent from the atom. 11P NMR spectra of reaction solutions. However, it turns out that 2 reacts with cyclic diaminophospho- rus halides bearing bulky substituents ('Bu groups) (i) at the nitrogen atoms to give reasonably stable prod­ / -N»7 V © N ------S x A N S ucts (7a, 7b). Compounds 7c and 7d with the less / > < S \ -------- 5Ü--------- / X \ \ bulky N'Pr groups had to be characterized at low (OC)3Fe —---------Fe(CO)3 -C4H10, -Li (OC^Fe -----------Fe(CO>3 temperature. \ DBU f 2 The boron-substituted tetrahedranes 8 can be readily isolated if at least one dialkylamino group is linked to boron. All attempts to obtain dialkyl- boryl derivatives failed. Although 2 reacts with the 9-BBN derivatives 9-chloro- and 9-methoxy- * Reprint requests to Prof. Dr. M. Herberhold. borabicyclo[3.3.1 jnonane, it was not possible so 0939-5075/96/0900-1283 $ 06.00 © 1996 Verlag der Zeitschrift für Naturforschung. All rights reserved. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung This work has been digitalized and published in 2013 by Verlag Zeitschrift in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der für Naturforschung in cooperation with the Max Planck Society for the Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Advancement of Science under a Creative Commons Attribution Creative Commons Namensnennung 4.0 Lizenz. 4.0 International License. 1284 M. Herberhold et al. ■ N-Functionalization of the Tetrahedrane Fe 2 (CO)6 (//-SNH) M RR' R,R'M 3a Si Me Me \ 3b Si Me H N ------S 3c Si Me ‘Bu /,X\ 3d Si Me SiM e, (OC )3Fe ______ _ Fe( CO)3 3e Si 'Bu H 3 f Si Ph ’Bu 3. 4. 5 4 Ge Me Me 5a Sn Me Me A 5b Sn Et Et tßu,As \ R,RMC1 N ------S -er / X } , R R (OC)3F e _ ______Fe(C O )3 ^ \ t B u , A s C l ( PCI ( p 6a -er \ © N ------S R R N ------S / > v -CI /X\' (O C ),F c _ ------- _F e(C O )3 (OC)3Fe _____ _ Fe(CO)3 r °, f ASCI. As k Ö \ R f \ N ------S 7a ‘Bu (C H ,), ‘Bu (C H ,), A X s > RRBCI 7b (OC)3F c __ ____ _F e(C O )3 'Pr (C H ,), -er 7c 7d ‘Pr (S iM e,), 6b RR'B RR N ------S 8a N'Pr, N'Pr, / X c 8b N(Bu)CH:CH:NBu (OC)3Fe ______ _F e(C O )3 8c N M e2 Fe Scheine 1 ^ SiMe,SiMe2v^ sr > N ' ' n —- s / / W / x \ \ (OC)3Ft------------Fe(CO)3 (OC)3Fe-------------Fe(CO)3 9 CISiMe2SiMe2Cl -2CI" ° Nc > s 2 / ^ \N (OC)3Fe—--------- Fe(CO)3 ClSiMe2OSiMe2Cl ClSiMe2CH2CH2SiMe2Cl -2 C r -2 CI' ^ SiMe,OSiMe,^ ^ SiMe2CH2CH2SiMe^ S -—- N N ----- S S----- N ----- S // X \ / X o / / V \ / X \ - (OC)3Fe------------Fe( CO )3 (OC )3Fe - ---------- Fe(CO)3 (OC)3Fe------------Fe(CO)3 (OC)3Fe------------Fe(CO)3 10 11 Scheine 2 M. Herberhold et al. • N-Functionalization of the Tetrahedrane Fe 2 (CO)6 (//,-SN H ) 1285 Table I. I5N, 2ySi and 31P NMR data of the tetrahedranes spectra (see Experimental part). In the IR spectra the 3 and 7 (chemical shifts [ppm], coupling constants [Hz], z/(CO) absorptions appear as a characteristic pattern solvent: CaD^, 25°C). of five or six bands indicating a Fe 2(CO)6 unit of b'5 N <$29Si 1 y(29si, I5n ) Cs or lower symmetry [5]. In the mass spectra, the molecular ions are detected together with fragments 3a -359.2 35.5 5.6 generated by stepwise loss of CO. 3b -370|al 22.1 3c -371.0 35.6 5.6 The nature of the element-nitrogen bonds in 3 - 3d -362.1 -19.7 (SiMe->), 3.9 11 is of particular interest. In the cases of 3 and 32.1 (SiMei) 7, LiN NMR spectra were measured (Table I), in 3e -374,0 30.8 addition to 29Si or 11P NMR spectra (cf. Figures 1 3f [d] 9.8 and 2), and chemical shifts <5ll9Sn and 6n B were <515N ^31P '7(3IP,I5N) determined for compounds 5 and 8. 7a|b| -292.0 (cycle), 137.5 59.6 (cycle). The magnitude of the coupling constants -292.2 (Fe.SN) 99.6 (Fe-iSN) l'7(29Si,15N)l is small, similar to '7(29Si,l5N) in 2,5- 7b|b| -296.6 (Fe2SN), 119.6 94.0 (FeiSN), dihydro-1,2,5-azoniasilaboratoles 16,7], in which -300.3 (cycle) 72.0 (cycle) an ammonium-type nitrogen atom is present. The 7c [d] 136.1 intensities of the 29Si satellites in the l5N NMR 7d|c| 168.1 [d] spectra of 3 are somewhat higher than expected. [a]: <5(14N); [b]: -20°C; [c]: <$(29Si) = -4.6ppm, 27(31 P,29Si) It is therefore assumed that 57Fe satellites over­ = 11.7Hz; [d]: not measured. lap with the 29Si satellites. The coupling constants 'y(57Fe,l5N) are in the same order of magnitude far to isolate well-defined products. The n B NMR (« 6 Hz [2]) as *y(29Si,15N). In the case of 7, as in spectra of reaction solutions indicate the formation other phosphorus-nitrogen compounds [8], the mag­ of (9-BBN)tO (b 11 B = 58.0 [4]) which suggests an nitude and the sign (usually positive; reduced cou­ unexpected course of these reactions. pling constant 1 K(31 P,I5N) < 0) of the coupling con­ stants 17(3IP,15N) are dominated by the phosphorus Spectroscopic results atom, in particular by the influence of the lone pair of electrons [9]. Therefore, the '/ ( 3IP,15N) values All compounds 3 -1 1 were characterized by IR, of 7 are rather similar to those measured for deriva­ 'H and l3C NMR. and in most cases by El mass tives in which the azadiferrathia tetrahedrane unit is replaced by the Me2N group [10]. The neighbour- S(,5N) -290 -300 Fig. 1. 30.4 MHz l3N NMR spectrum of 6(15N) Fe2(CO)6(//-SN-SiMe2?Bu) (3c) (saturated in CaD^, 25°C), measured by using the refocused INEPT pulse Fig. 2. 30.4 MHz 15N{1H} NMR spectrum of sequence (based on 37(lsNSiC'H) « 1.5 Hz). 2ySi satel­ Fe2(CO)6[/i-SN-P(NCBu)CH2)->CH'>] (7b) (1 g in C7DS, lites are marked with arrows. -20°C. 1286 M. Herberhold et al. ■ N-Functionalization of the Tetrahedrane Fe 2 (CO)6 (^ -S N H ) Table II. Selected bond lengths |pm] and angles [°J in 0(4) [Fe2(CO)6(//-SN-SiMe2CH2‘'-)]2 (11). S-N 169.2(3) Fe( 1)- S - Fe(2) 69.4( 1) Fe( 1) - Fe(2) 250.6(1) Fe( 1) - S - N 58.4( 1) Fe( 1) - N 194.8(3) Fe(2) - S - N 58.0(1) Fe(2)- N 194.4(2) Fe( 1) - Fe(2) - S 55.1(1) Fe(1)- S 219.8(1) Fe(2) - Fe( 1)- S 55.5( 1) Fe(2)- S 220.7(1) N - Fe( 1) - S 47.7(1) N -S i 178.5(3) Fe(l) - N -Si 134.3(1) F e (l)-C (l) 179.5(4) Fe(2) - N -Si 138.9(2) Fe(1)-C(2) 179.3(3) S - N - Si 129.1(1) Fe(1)-C(3) 180.8(3) C(8) - Si - C(9) 112.7(1) Fig.