Bowl-shaped molybdenum complexes containing tris(3-p-methoxyphenylpyrazol-l-yl)borate (Tp~(An)) Crystal structures of [Mo(Tp~(An))(NO)(Cl)(NHC_6H_4-p-CH_3)] and [Mo(Tp~(An))(NO)(Cl){NHC_6H_4-p-N(CH_3)_2}]

摘要

New arylamide complexes of the type [Mo(Tp~(An))(NO)(Cl)(NHC_6H_4-p-R)] (Tp~(An) = hydrotris(3-p-metoxyrazol-l-yl)borate; R = CH_3O (1), N(CH_3)_2 (2), Cl (3), CH_3 (4)) have been prepared inorder to deduce the influence different arylamide para-substitutents have on their molecular structure and properties. The sngle-crystal X-ray structure of [Mo(Tp~(An))(NO)(Cl){NHC_6H_4-p-N(CH_3)_2}] (2 and [Mo(Tp~(An))(NO)(Cl)(NHC_6H_4-p-CH_3)] (4) have been solved, both of them having a characteristic bowl-like molecular shape. The influece of electronic and steric factors on the shape of the bowl cavity is discussed. Both compounds have a columnar packing arrangement with molecular interpenetrating between neighbouring columns. Gien that columnar stacking could be appropriate for liquid crystal materials, new related complexes bearing long-chain substituted arylamide ligands [Mo(Tp~(An))(NO)(Cl)(NHC_6H_4-p-C_nH_(2n+1))] (n = 6, 10, 12, 14, 16; 5-9) have been prepared.