1.3- Dimesitylimidazol-2-ylidene, stable complexes

Reaction of l,3-bis(phenylmethyl)imidazol-2-ylidene with nickel tetra carbonyl gives [(t (C)-1,3-bis(phenylmethyl)imidazol-2-ylidene)Ni(CO)3] (970M2472). Complexes of composition [Ni(CO)2L2] with imidazol-2-ylidenes are also known (93JOM(459)177). Another species to be mentioned in this respect is bis(l,3-dimesitylimidazol-2-ylidene)nickel(0) (94JA4391). 1,3-Dicyclohexylimidazol-2-yUdene substitutes triphenylphosphine or THF from [NiX LJ (X = Cl, Br L PPhj, THF) to yield the stable nickel(II) complexes 69 (X = C1, Br R = Cy) (97OM2209). Another preparation of nickel(II) derivatives is the interaction of... 

The synthesis and characterization of Et2Zn adducts with nucleophilic carbenes see Carbene Complexes have been described. They are directly available and in good yields from a smooth reaction between Et2 Zn and stable carbenes (see Carbene Complexes such as 1,3-dimesitylimidazol-2-ylidene or l,3-di(l-adamantyl)imidazol-2-ylidene (equation 13). The solid-state structure of [Et2Zn l,3-di(l-adamantyl)imidazol-2-ylidene ] shows a zinc atom in a rather unusual trigonal planar arrangement, certainly due to a steric... 

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