Two Alternatives of Heteroallene Insertion in Metal - Ligand Bonds of Five-Coordinate Ruthenium(II) and Osmium(II) Complexes [MXY(CO)(PiPr3)2]
✍ Scribed by Werner, Helmut ;Tena, Miguel Angel ;Mahr, Norbert ;Peters, Karl ;Schnering, Hans-Georg Von
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1995
- Tongue
- English
- Weight
- 784 KB
- Volume
- 128
- Category
- Article
- ISSN
- 0009-2940
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✦ Synopsis
Ruthenium complexes I Osmium complexes I Insertion reactions I Carbon disulfide I Carbon dioxide I Methyl isothiocyanate I Zwitterionic ligands The five-coordinate chloro(hydrido)-and hydrido(iod0)ruthenium(I1) and -osmium(II) compounds [MHX(CO)(PiPr&] (1, 2, 6, 7) react with CS2 to give the octahedral dithioformato complexes [MC1(CO)(PiPr3),(q2-S2CH)] (3, 4, 8, 9) in excellent yields. In the initial step, an addition of the heteroallene to the metal center occurs which is followed by insertion of CS2 into the M-H bond. On treatment of the dichlororuthenium(I1) derivative [ R U C ~~( C O ) ( P ~P ~, ) ~] (lO), which is prepared from RuC13 . aq and PiPr3 in methanol, with carbon disulfide insertion into one of the Ru-PiPq bonds takes place to give the six-coordinate ruthenium(I1) complex 12 with the zwitterion -S2CPiPr,f as a chelating ligand. While the reaction of [OsH(SPh)(CO)(PiPr,),] (13) with MeSCN leads to addition of the thionitrile to the metal center, the starting material reacts with MeNCS by insertion of the heteroallene into the 0s-SPh bond to give two stereoisomers 15a, b, in which the nitrogen atom of the chelate ring is either cis or tram to the hydrido ligand. The octahedral methoxydithiocarbonatoand formatoosmium(I1) compounds 16 and 17 are prepared from 2 and CS2 or CO, in the presence of NaOMe. The crystal and molecular structures of 4 (M = OS), 12 and 15a have been determined. We have recently shown that the coordinatively unsaturated chloro(hydrido)ruthenium(II) and -osmium(II) compounds [MHCl(CO)(PiPr3)2] (1, 2) react with small molecules L such as H2, 02, CO, CNR and CH2=CHX to form octahedral complexes [MHCl(CO)(PiPr3)2L] in which the new ligand L occupies the free coordination site[',2]. If the starting materials 1, 2 are transformed into the corresponding hydrido(pheno1ato)-and hydrido(thiopheno1ato)metal derivatives [ M H ( E C ~X , ) ( C ~) ( P Z ~~~) ~]
(E = 0, S; X = H, F), we have observed that these compounds on treatment with CS2 undergo insertion reactions to yield the chelate complexes [MH(T~*-S~COC~X~)(CO)(P~P~~)~] and [MH(q2-s2csc6x,)(cO)(PiPr~)2], respecti~ely [~]. Since terminal alkynes insert into the M-H bond of l and 2I4l, we were interested to know whether a similar process could occur with heteroallenes such as CS2, SCNR, OCNR and even with COz. In this paper we describe the synthesis of dithioformato-, dithiocarbamato-, dithiocarbonato-, and formatoruthenium and -osmium compounds which are all formed by heteroallene insertion. We furthermore report that in the absence of a hydrido or thiophenolato ligand, a five-coordinate d6 metal complex of general composition [MX2(CO)(PR&] can equally undergo a CS2 insertion, in this case however, not into the M-X but into one of the M-PR3 bonds.
Results
Insertion of CS2 into Ru-H and OS-H Bonds