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

Article abstract of DOI:10.1016/j.poly.2005.10.003

The reaction of the thiosemicarbazones (η⁵-C ₅H₅)Fe(η⁵-C₅H ₄)C(H)NN(H)C(S)NHR (R = H, a; R = Me, b) with K₂PdCl ₄ afforded octanuclear cyclometallated complexes [Pd{(η ⁵-C₅H₅)Fe(η⁵-C₅H ₃)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-C₆H ₁₄ gave rise to tetranuclear complexes [{Pd[(η⁵-C ₅H₅)Fe(η⁵-C₅H ₄)C(H)NNC(S)NHR](Cl)}₂(μ-Ph₂P(CH ₂)_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 CH₂Cl ₂/n-C₆H₁₄ gave rise to dinuclear complexes [Pd{(η⁵-C₅H₅)Fe(η⁵-C ₅H₄)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(C ₆D₅)₃, 6b). The crystal structures of 2a and 2b have been determined by X-ray crystallography.