Synthesis of transition metal isocyanide complexes containing hydrogen bonding sites in peripheral locations

The isocyanides CNC6H2R2-2,6-CHO-4 (1a-b) (a: R = Me; b: R = CHMe2), react with hydroxylamine, 2-pyridylhydrazine, and formylhydrazide to form CNC6H2R2-2,6-CHNOH-4 (2a-b), CNC6H2R2-2,6-CHNNH(2-C5H4N)-4 (3a-b), and CNC6H2R2-2,6-CHNNHCHO-4 (4b), respectively. The oxime and hydrazone derivatives 2-4 were chosen because of their potential for self-association via hydrogen bonding. Reaction of the isocyanides 1-4 (L) with FeI2, PdI2, and PtI2 affords complexes of the types trans-[FeI2(L-4)], trans-[PdI2(L)(2)], and trans-[PtI2(L-2)]. The molecular structures of the complexes trans-[FeI2(L-4)] (L = 1b, 2a and 2b) and trans-[PdI2 (L)(2)] (L = 2b) were determined by X-ray crystallography. The oxime derivatives form extended hydrogen bonded networks. (C) 1999 Elsevier Science S.A. All rights reserved.