Interaction of organolead(IV) derivatives with formyl- and acetylferrocene thiosemicarbazones: Coordination versus dephenylation or reductive elimination processes

• Published in: Journal of organometallic chemistry Vol. 692; no. 11; pp. 2234 - 2244
• Main Authors: Casas, J.S., Castaño, M.V., Cifuentes, M.C., García-Monteagudo, J.C., Sánchez, A., Sordo, J., Touceda, A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-05-2007
• Subjects: 13C and 207Pb NMR spectra; Acetylferrocene thiosemicarbazones; Cyclic voltammetry; Dephenylation; Dimethyllead(IV); Diphenyllead(IV) complexes; Formylferrocene thiosemicarbazones; IR spectra; Mass spectra; Reductive elimination; Triphenyllead(IV); X-ray structures; Cyclic voltammetry; Diphenyllead(IV) complexes; Acetylferrocene thiosemicarbazones; Dephenylation; 1H; IR spectra; Reductive elimination; Formylferrocene thiosemicarbazones; Triphenyllead(IV); Dimethyllead(IV); Mass spectra; X-ray structures
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/j.jorganchem.2007.01.049

The reaction of diphenyllead(IV) derivatives with the title ligands (HTSC) in methanol afforded either 1:2 adducts or 1:1 complexes (see scheme). With triphenyllead(IV), dephenylation occurred leading to diphenyllead(IV) compounds. The reaction of Me
2Pb(OAc)
2 and HTSC afforded only Pb(II) derivatives.
The reaction of Ph
2PbCl
2 with formylferrocene and acetylferrocene thiosemicarbazones (HTSCs) in methanol afforded the corresponding adduct [Ph
2PbCl
2(HTSC)
2] or, in one case, the complex [Ph
2PbCl(TSC)]. X-ray crystallography of four of the adducts showed them to be all-
trans octahedral complexes with the HTSC ligand S-bound to the metal. The IR spectrum of [Ph
2PbCl(TSC)] suggests that the TSC
− ligand is N,S-coordinated. The reaction of Ph
2Pb(OAc)
2 with HTSCs in methanol gave either [Ph
2Pb(OAc)
2(HTSC)
2] or [Ph
2Pb(OAc)(TSC)], which was also obtained from Ph
3Pb(OAc) via a spontaneous dephenylation process. In the former complexes the HTSC ligand is S-coordinated in the solid state. X-ray crystallography of two of the four [Ph
2Pb(OAc)(TSC)] complexes showed that the thiosemicarbazonate anion is N,S-coordinated and the acetate is anisobidentate. Cyclic voltammetry of one [Ph
2PbCl
2(HTSC)
2] adduct and the corresponding [Ph
2Pb(OAc)(TSC)] complex showed that the inductive effect of coordination to lead is transmitted to the ferrocenyl group. Surprisingly, the reaction of Me
2Pb(OAc)
2 with HTSCs afforded only [Pb(TSC)
2] complexes, possibly via redistribution and reductive elimination processes.