Spectroscopic and thermal study of dialkyl (alpha-anilino-N-benzyl)phosphonates and their palladium(II) dichloride adducts

摘要

Spectroscopic (C-13 NMR, UV/VIS, IR, FAB-mass) and thermal (TG, DTA) studies of dialkyl (alpha- anilino-N-benzyl)phosphonates and their palladium(II) dichloride adducts, trans-Pd(L)(2)Cl-2, have been carried out to determine structural and decomposition properties of these biologically active compounds. Thermal decomposition of the complexes proceeds in two steps : dehalogenation coupled with deesterification is followed by complex pyrolysis which finally results in a mixture of Pd and P2O5. The main gas-phase fragmentation pathway consists of sequential losses of HCl giving rise to the mono- and bis-orthometallated species. These processes are in competition with the loss of the phosphonate ester groups. NMR and UV/VIS spectra have shown that complexes retain their integrity in chloroform; but dissociate readily in DMSO and DMF solutions, leaving free an organophosphorus ligand. The spectral and thermal properties of the complexes have been discussed with respect to their antitumor activity. (C) 1998 Elsevier Science Ltd. All rights reserved. [References: 35]