The synthesis and X-ray study of (η6-benzamide)- and (η6-phenylacetamide)tricarbonyl chromium complexes. Structural effects of the substituent

(η6-Benzamide)tricarbonylchromium and tricarbonyl(η6-phenylacetamide)chromium (1 and 2) have been synthesized from the corresponding amides and chromium hexacarbonyl. Decalin, a mixture of decalin and butyl acetate, and neat butyl acetate have been used as the reaction media. The first system gave best yields. Both amide complexes form adducts with non-complexed molecules of the type [(CO3)CrL] · L through hydrogen bonds, suggested on the basis of 1H and 13C NMR spectroscopy. Similar associations by hydrogen bonds exist in the solid state structure of 3 and 4. The π-donor-acceptor abilities of the substituents on the rings are discussed on the basis of geometrical parameters and 13C NMR dat…