IR study of the N,N′,N"-triphenylguanidine and its imine nitrogen coordinated Pd(II) complexes

Infrared spectra of N,N ' ,N " -triphenylguanidine (PhNH)(2)C=NPh (Ph(3)G) and its imine nitrogen coordinated Pd(II) complexes (trans-Pd(Ph(3)G)(2)Cl-2 and [Pd(Ph(3)G)(4)](ClO4)(2)) have been studied in the 4000-150cm(-1) frequency range. Complete equilibrium geometry of the Ph3G has been determined by ab initio calculations employing two different levels of the theory: HF/6-31G* and DFT (B3LYP/6-31G*). The theoretical predictions are discussed and compared with experimental results were appropriate. A complete vibrational assignment of the solid-state IR spectrum of Ph3G was performed on the basis of normal coordinate analysis of a single molecule. The coordination of Ph3G to Pd(II) through imine nitrogen has been confirmed by study of the IR spectrum of trans-Pd(Ph3G)2Cl2 complex. On the basis of the IR study of the ligand and its Pd (II) complexes a mono-dentate coordination of the ligands in the [Pd(Ph(3)G)(4)](ClO4)(2) Complex was suggested. (C) 2001 Elsevier Science BN. All rights reserved.