Monosubstituted derivatives of tetracobalt dodecacarbonyl

Coordinated Isonitriles

“…The IR spectra of Cr°(CN-R) 6 and Ni°(CN-R) 4 could provide further criteria to test the validity of the VB and MO models. Since both complexes are highly symmetric (octahedral and tetrahedral configurations) they should exhibit only one NC stretching frequency unless back donation lowers the symmetry by bending the CNC axis.…”

“…A small contribution from an ylide form XVa is indicated by a shortening of the NC bond to 1.32 Á. Strong bases like phenyllithium react with Cr(CO) 6 according to reaction (6). Methylation of the complex XVII leads to stable compound XVIII, the first carbene complex to be reported.…”

“…The conversion of isocyanates to carbodiimides and C0 2 is catalyzed by metal carbonyls [Fe 2 (CO) 9 , Fe(CO) 5 , W(CO) 6 , Mo(CO) 6 ]. This process represents a further illustration of the reactivity of isonitrile complexes which are intermediates in this reaction.…”

“…It is questionable whether the cyclic intermediate XLVIII is involved as Ulrich has suggested, because in the cases of Mo(CO) 6 or W(CO) 6 the formation of an unusual, heptacoordinated monosubstituted metal carbonyl is required. Also the simultaneous bond making and bond breaking of XLVII to form the isonitrile complex XLIX and release of C0 2 seems to be quite plausible.…”

“…21 Another alkylating agent is dimethylsulfate. 15 H 4 Fe(CN) 6 reacts with diazomethane 29 and even with alcohol 16 to give isonitrile complexes. The transalkylation reaction mentioned above extends the limited application of the simple alkylation reaction.…”