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s2O3 + 4 MeCO2K [(AsMe2)2O] + [Me2As-AsMe2] + … M)#$&;$-"#$H#1$#B#)-0$&;$-"#$<><-"$/#)-2*1$A,0$-"#$3(0/&B#*1$&;$-"#$;(*0-$!$/&'?.#K6 R ),'#.1$N#(0#$0,[email protected]" IGRSTUV6$()$CWRD6$,.-"&2+"$-"#$/&**#/-$;&*'2.,$%#.&A A,0$?*&?&0#3$'2/"$.,--#*= – Cl Pt K+ Zeise salt, 1827 Cl Cl >)$-"#$'(3ICWXF06$Y*,)H.,)3$01)-"#0(Z#3$0#B#*,.$,(*I0#)0(-(B#$'#-,.I,.H1.$/&'?.#K#0 02/"$,0$N)7-R$QCWT[U6$S+7-R$QCWXRU6$5)7-T$,)3$\]#9$QCWEFU6$-"#$'#*/2*1$,)3$Z()/ /&'?.#K#0$%#()+$(''#3(,-#.1$20#3$-&$01)-"#0(Z#$',)1$&-"#*$',()I+*&2?$&*+,)&'#-I ,..(/$/&'?.#K#0=$Y&*$()0-,)/#6$Y*(#3#.$,)3$G*,;-0$?*#?,*#3$0#B#*,.$&*+,)&/".&*&0(I .,)#0$^)5(G.T_)$;*&'$-"#$*#,/-(&)0$&;$5(G.T$A(-"$N)^R$QCWE9U=$5"&*-.1$,;-#*A,*306 5/"`-Z#)%#*+#*6$,)$a.0,-(,)$/"#'(0-6$01)-"#0(Z#3$-"#$;(*0-$'#-,.I/,*%&)1.$3#*(B,I -(B#[email protected]$,)[email protected]$QCWEWICWDFU=$!A#)-1$1#,*0$.,-#*6$-"#$;(*0-$%(),*1 '#-,.I/,*%&)1.$/&'?&2)30$,??#,*#3L$Pb(QGMUTV$Q]&)36$CW[FU$,)3$PY#QGMUXV$Q]&)3 ,)3$\#*-"#.&-6$CW[CU=$Y*&'$CW[9$&)A,*30$,)3$&B#*$,$?#*(&3$&;$-A#)-1$1#,*06$c#*)#* 3#B#.&?#3$-"#$'&3#*)$(3#,0$&;$()&*+,)(/$/"#'(0-*1$()$"(0$?*&?&0,.$,//&*3()+$-& 9d 9d A"(/"$-"#$G& $(&)$(0$02**&2)3#3$%1$0(K$.(+,)30$()$,)$&/-,"#3*,.$/&'?.#K$PG&eEV = !"#0#$(3#,0$A#*#$/&)-*,*1$-&$-"&0#$?*&?&0#3$%1$-"#$A#..IH)&A)$/"#'(0-0$&;$-",- -('#$02/"$,0$f&*+#)0#)6$,//&*3()+$-&$A"&'$-"#$.(+,)30$0"&2.3$%#$,.(+)#3$()$,$/",() A(-"$-"#$'#-,.$,-$-"#$-#*'()20= 6 ORGANOMETALLIC CHEMISTRY AND CATALYSIS 1900-1950: GRIGNARD, SABATIER, AND CATALYSIS IN GERMANY It is at the turn of the X Xth century that the major French contribution came into fruition with the work of Barbier and especially of his student Victor Grignard. Grignard’s name is forever engraved in the history of chemistry for the reaction of magnesium with organic halides RX leading, by oxidative addition, to Grignard reagent RMgX that can alkylate carbonyl derivatives. MgR’COR’’ RX RMgX RR’R’’COH Et2O This discovery had an enormous impact, not only on organic chemistry, but also proved to be of considerable importance in transition-metal organometallic chemis- try. For instance, in 1919, Hein synthesized what he believed to be a polyphenyl- chromium derivative [(Cr(!-Ph)n]: !0,+1 CrCl3 + PhMgBr [Cr(!-Ph)n] n = 2, 3 or 4 However, some 36 years later, it was revealed that the compound posseses a " sandwich-type structure. The first half of the XXth century was especially noteworthy for the emergence of catalysis. The distinction between homogeneous and heterogeneous catalysis was first delineated by the French chemist Paul Sabatier (one of Berthelot’s students). Sabatier and Senderens’ work on the heterogeneous hydrogenation of olefins to saturated hydrocarbons using nickel eventually led to a Nobel Prize shared in 1912 between Sabatier and Grignard. Many seminal discoveries, however, were made in Germany during this first half of the XXth century. In 1922, Fischer and Tropsch reported the heterogeneously catalyzed reaction between CO and H2 (syngas) to form mixtures of linear alkanes and alkenes with few oxygenates as by-products (Fischer-Tropsch process, industrially developed in 1925). In 1938, Roelen dis- covered the catalysis by [Co2(CO)8] of the hydroformylation of olefins by CO and H2 (oxo process). From 1939 to the late 1940s, Reppe worked on the catalysis of transformation of alkynes (tetramerization to cyclo-octatetraene, 1948). Curiously, there were only a few advances in the discovery of new complexes dur- ing this period. Besides iodotrimethylplatinum, [PtMe3I], synthesized by Pope at the th 4 beginning of the XX century, the list includes [Fe(# -butadiene)(CO)3] made by Reilhen in 1930 and Hieber’s work on metal carbonyls from 1928 onwards (e.g. the synthesis of [Fe(H)2(CO)4], 1931). HISTORY OF ORGANOMETALLIC CHEMISTRY 7 H H3C CH3 OC CO Pt Fe Fe H3C I OC CO OC CO CO H First ␴-alkyl-metal complex First diene-complex First metal-hydride complex Pope, 1909 Reilhen, 1930 Hieber, 1931 1950-1960: THE DISCOVERY OF FERROCENE AND THE BOOM OF ORGANOMETALLIC CHEMISTRY It is in the 1950s that inorganic and organometallic chemistry boomed, especially in the United States. Henry Taube classified the inorganic complexes as inert or labile towards substitution reactions, depending on the nature of the ligand and oxidation state of the metal (1951). This work laid the foundation of molecular engineering that allowed him to carry out a crucial series of experiments: the catalysis of sub- stitution reactions by electron or atom transfer, and the distinction between outer- sphere electron transfer and that proceeding by the inner sphere which is considerably faster (1953). Structural bio-organometallic chemistry has its origin with the English chemist Dorothy Crowfoot-Hodgkin who established the X-ray crystal structure of Vitamin B12 coenzyme between 1953 and 1961 using a primitiVe computer, resulting in her awarding the Nobel Prize in 1964. ConsecutiVely, the legendary HarVard UniVersity chemist Robert B. Woodward achieVed the total synthesis of this coenzyme in 70!steps with 99 co-workers from 1961 to 1972. In England too, seVeral chemists had noted, at the beginning of the 1950s, this Very stable orange powder that formed when cyclopentadiene is passed through iron tubings. Some chemists had eVen filled pots with it in their laboratory. Keally, Pauson and Miller first published the compound in 1951, and Pauson reported the structure [Fe(!-C5H5)2] in the journal Nature. In doing so, he made the same mis- take as Hein, 32 years earlier. In the meantime, howeVer, Sidgwick had published the 18-electron rule for transition-metal complexes in his book “!The Electronic Theory of Valency!” (Cornell UniVersity, Ithaca, 1927). Pauson’s proposed ! structure for bis-cyclopentadienyl-iron only had 10 Valence electrons and was soon challenged. At HarVard UniVersity, Willkinson and Woodward recognizing Sidgwick’s rule, immediately understood that the Pauson formulation was incorrect. A few months later, they published the first sandwich structure, just before Fischer: bis-cyclopentadienyl-iron is ferrocene, an 18-electron complex, in which the two rings are perfectly parallel, "-bound to the iron atom and haVing aromatic properties (1952). ! " , ,%)%*0/+/ R.B. Woodward and Ferrocene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ature ?K83JH:F4< H9 (9GJ>9< 29 14I4Q345 @ZE @AZ@E >9< >55HM4< H9 6F4 \O/O >3286 > Q296F J>645D 62 I>55L 286 > :45H4: 2P 4]K45HQ496: =H6F 'L529 #2:4Q3J8QE > G5><8>64 :68<496E 6F454>P645 J4< 62 6F4 JACS I2QQ89HI>6H29 2P @AZRO )F4 K522P P25 6F4 :>9<=HIF :658I6854 =>: 6F4 <HK2J4 Q2Q496 6F>6 =>: W452 >9< 6F4 H9P5>54< :K4I658Q :F2=H9G 29JL 294 6LK4 2P ,C. 329<O +6 =>: ;22<=>5<E F2=4M45E =F2 54I2G9HW4< 6F>6 P4552I494 =28J< 34F>M4 JHT4 > 6LKHI>J >52Q>6HI I2QK289<E >9< ;HJTH9:29 J>645 >IT92=J4<G4< 6F>6 F4 F>< 926 I29:H<454< 6FH: K2::H3HJH6LO *>645 H9 @AZRE >926F45 >56HIJ4 P52Q ;22<=>5<E #2:493J8Q >9< ;FH6H9G H9 JACS I29PH5Q4< "9 "I62345 R^E @ABVE 6=2 <>L: >P645 6F4 >99289I4Q496 2P 6F4 &234J N5HW4E ;22<=>5< Q>HJ4< > J46645 P52Q *29<29 62 6F4 &234J ,2QQH6644 H9 =FHIF F4 :6>64<_ `The notice in the Times (October 24, p. 5) of the award of this year’s Nobel Prize in Chemistry leaves me no choice but to let you know, most respectfully, that you have –!inadvertently, I am sure!– committed a grave injustice… Indeed, when I, as a gesture to a friend and junior colleague interested in organometallic chemistry, invited Professor Wilkinson to join me and my colleagues in the simple experiments which verified my structural proposal, his reaction to my views was close to derision… But in the event, he had second thoughts about his initial scoffing view to my structural proposal and its consequences, and altogether we published the initial seminal communication that was written by meOa%II25<H9G 62 ;HJTH9:29E F2=4M45E H6 =>: =F49 F4 Jesus-Christ it can’t be that. It’s a sandwich!a +9<44<E 6F454 =>: 522Q P25 >926F45 K45:29 H9 6FH: &234J N5HW4E 386 H6 H: K2::H3J4E >: :6>64< 3L #2>J< .2PPQ>99E 6F>6 > :65>64GHI 45525 2P ;22<=>5< =>: 926 62 4]K>9< FH: 25G>92Q46>JJHI 54:4>5IF 62 H9IJ8<4 26F45 65>9:H6H29 Q46>J: >9< H9:64>< I29I4965>64 29 6F4 >52Q>6HI IF4QH:65L 2P P4552I494O %I68>JJLE 34P254 ;22<=>5< >9< ;HJTH9:29[: =25TE ;HJJH>Q (O 1245H9G >6 ,2J8Q3H> :8GG4:64< H9 /4K64Q345 @AZ@ 6F4 :>9<=HIF :658I6854 62