Trans-influences in mononuclear cyclopalladated compounds containing a sigma(Pd-C-sp2, ferrocene) bond. X-ray crystal structures of [Pd{[(eta(5)-C5H3)-CH=N-CH2-C6H5]Fe(eta(5)-C5H5)}(X)(PPh3)] with X- = Br- and I-

The syntheses, characterization and study of the properties of cyclopallada ted compounds of general formula: CPd{[(eta (5)-C5H3)CH=N-CH2-C6H5]Fe(eta ( 5)-C5H5)}(X)(PPh3)] with X- = Cl-, Br-, I-, CN-, SCN- or AcO- are reported. Compounds with X- = Br- and I- were characterized by X-ray diffraction, an d their crystal structures revealed the existence of a weak C-H X interacti on involving one of the -CH2- type hydrogen atoms bound to the imine nitrog en. Comparison of the spectroscopic properties of these compounds has allow ed us to elucidate the influence of the monoanionic ligand, X-, on a tuans- arrangement to the metallated carbon atom upon the environment of the iron( II). Theoretical studies based on the semiempirical PM3(tm) were also been carried out to clarify the effects produced by the X- ligand on the ring cu rrent of the metallated C,H, ring of the ferrocenyl fragment. (C) 2001 Else vier Science B.V. All rights reserved.