Thiocarbonyl complexes bonding

Ir(CO)(CS2)(PPh3)2](BPli4). It was formulated as an octahedral species with a rc-bonded CS2 ligand, as in (64). However, when attempts were made to alkylate [Ir(CO)(CS2)(PPh3)2]+ to form the dithioester complex, which should have reacted with acids in an alternative route to the thiocarbonyl complex, the reactions proved unsuccessful. The complex turned out to be... 

Therefore, rr-acceptor versus (T-donor properties of CS and CSe change more drastically than those of CO. In thiocarbonyl complexes additional bonding contribution comes from In orbitals. 

Thiocarbonyls CS is not stable above - 160 C in the free state, but a number of complexes are known, such as RhCl(CS)(PPh3) (Eq. 4.16) and Cp(CO)Ru( x -CS)2RuCp(CO), but so far no pure or homoleptic examples M(CS) . They are usually made from CS2 or by conversion of a CO to a CS group. Perhaps because of the lower tendency of the second row elements such as S to form double bonds, the M =C—S form analogous to 4.2 is more important for MCS than MCO the MC bond therefore tends to be short and CS is a better ir acceptor than CO. Perhaps for this reason, CO and not CS tends to be substituted in a mixed carbonyl-thiocarbonyl complex. 

The associative substitution reactions of metal carbonyls, and the preparations, bonding and reactivity of thiocarbonyl complexes were also reviewed in 1985. 

Liganded cobalt complexes react with carbon disulfide by addition across one of the C=S bonds to give relatively stable complexes 10. The same complex reacts with carbonyl sulfide to give a liganded carbonyl complex 11 andMesPS. In the reaction of carbon sulfose-lenide at -20 °C the adduct 12 as well as the thiocarbonyl complex 13 are formed, indicating that carbon sulfoselenide can be used for the synthesis of thiocarbonyl compounds. 

The complex (197) with a dithiocarboxylate ligand coordinated to platinum(II) bonded through both monodentate carbon and die chelating dithiocarboxylate ligand has been prepared from either the thiocarbonyl platinum(II) precursor or the carbon disulfide adduct of platinum(O).1796,1797 A cyclopentadienyl-substituted dithiocarboxylate ligand (198) can be used to prepared S,S-bonded platinum(II) and (IV) complexes Pt(C5H4CS2)2 and PtfCsKtCS 2-. The complexes show v(PtS) at 340 cm-1, and in each case electronic absorption bands of the Pt— L type are at 19 500 cm-1 and 29 500 cm-1.1798... 

Whereas coordination of a CA to a lone electron pair of a heteroatom containing only single bonds typically results in a hypsochromic shift of the CA absorption maxima, upon complexation of germylenes with S atoms of thiocarbonyl compounds (and also... 

Insertion of imsymmetrical heterocumulenes such as 0=C=X (X = S, NR), into an N-Si bond can produce two different constitutional isomers [8]. In the case of compound 1 and X = NR, R = alkyl or aryl, there is rapid insertion into both N-Si functions and the resulting situation is extremely complex with respect to the configurational (0,N-silylation) and conformational isomerism [5, 8, 10]. In contrast, 0=C=S inserts rapidly into only one N-Si bond of 1, there is no evidence for any second insertion even after several days. The formation of small amounts of pyrazine as oxidation product even under strictly anaerobic conditions suggests some electron transfer reactivity. Spectroscopic [10] and especially the structural evidence given below show that of the two conceivable constitutional isomers [11] of the insertion reaction only the 0-Si bonded species 2 with intact thiocarbonyl function is formed. 

---