Diorganozinc compound structure

Structural Studies of Diorganozinc Compounds Bearing a-Bound Ligands 326... 

Despite the extensive history of organozinc chemistry, the first solid-state structure of a Lewis base-free diorganozinc compound with cr-bound ligands, namely diphenylzinc, was not reported until 1990.37 Diphenylzinc was synthesized by the transmetallation of diphenylmercury with metallic zinc (Scheme 10) and, after multiple sublimations, obtained halide free in 67% yield. 

Reaction of two equivalents of 2-[(dimethylamino)methyl]ferrocenyUithium with ZnCl2 affords the corresponding diorganozinc compound (68) in which two 2-[(dimethylamino) methyl]ferrocenyl ligands are C,Af-chelate bonded to zinc. Due to the chirality of the bidentate ligands 68 exists in two diastereoisomeric forms. Indeed, in solution a meso one and an S,S)/ R,R) enantiomeric parr in a 1 4 ratio were observed by H and C NMR spectroscopy. However, it is only the S,S)/ R,R) enantiomeric pair that preferentially crystallizes from solution. An X-ray crystallographic study of such crystals afforded the structure of (R,R)/(S,S)-6S in the solid state (Figure 35). 

A number of relevant structures have been published. Table 5 summarizes some of the important bond lengths and bond angles found in complexes between diorganozinc compounds and amines. As a result of amine coordination, the geometry around the zinc center changes from linear to distorted tetrahedral (see Coordination Numbers Geometries). 

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