Synthesis and crystal structure analysis of ferrocenylthiosemicarbazone complexes of palladium(II): Unusual σPd–C bond cleavage

The reaction of the thiosemicarbazones (η5-C5H5)Fe(η5-C5H4)C(H)NN(H)C(S)NHR (R = H, a; R = Me, b) with K2PdCl4 afforded octanuclear cyclometallated complexes [Pd{(η5-C5H5)Fe(η5-C5H3)C(H)NNC(S)NHR}]4 (R = H, 1a; R = Me, 1b). Reaction of complexes 1a and 1b with tertiary diphosphines in 1:2 molar ratio and subsequent recrystallization from CH2Cl2/n-C6H14 gave rise to tetranuclear complexes [{Pd[(η5-C5H5)Fe(η5-C5H4)C(H)NNC(S)NHR](Cl)}2(μ-Ph2P(CH2)nPPh2)] (R = H, n = 4, 2a; R = Me, n = 1, 2b; n = 4, 3b). Treatment of complexes 1a and 1b with tertiary monophosphines in 1:4 molar ratio and subsequent recrystallization from CH2Cl2/n-C6H14 gave rise to dinuclear complexes [Pd{(η5-C5H5)Fe(η5-C5H4)C(H)NNC(S)–NHR}(Cl)(P)] (R = H: P = PPh3, 3a; P = PPh2Et, 4a; P = P(C6D5)3, 5a; R = Me: P = PPh3, 4b; P = PPh2Et, 5b; P = P(C6D5)3, 6b). The crystal structures of 2a and 2b have been determined by X-ray crystallography.

The thiosemicarbazone ligands (η5-C5H5)Fe(η5-C5H4)C(H)NNHC(S)NHR (R = H, Me) reacted with potassium tetrachloropalladate to give cyclometallated compounds with the organic ligand as terdentate [C, N, S], from which novel di- and tetranuclear species were obtained by reaction with the tertiary mono-, PPh3, PPh2Et, P(C6D5)3, and diphosphines, Ph2PCH2PPh2 (dppm) and Ph2P(CH2)4PPh2 (dppb), respectively.Figure optionsDownload as PowerPoint slide