Synthesis and Characterization of Pyrrolthiosemicarbazone Complexes of Palladium(II). Crystal Structures of [{Pd[C 4 H 4 NC(H)=NNC(S)NHMe](Cl)} 2 {μ‐Ph 2 P(CH 2 ) 3 PPh 2 }] and[Pd{C 4 H 4 NC(H)=NNC(S)NHMe}{Ph 2 P(CH 2 ) 2 PPh 2 ‐ P , P }](Cl)

Reaction of the thiosemicarbazone ligands C 4 H 4 NC(H)=NN(H)C(S)NHR (R = Me, a ; Et, b ) with Li 2 [PdCl 4 ] gave the dinuclear complexes [Pd{C 4 H 4 NC(H)=NNC(S)NHR}(μ‐Cl)] 2 (R = Me, 1a ; Et, 1b ) with a central Pd 2 Cl 2 core and with deprotonation of the thiosemicarbazones at the hydrazinic nitrogen atom. Treatment of 1a and 1b with triphenylphosphine gave the mononuclear compounds [Pd{C 4 H 4 C(H)=NNC(S)NHR}(Cl)(PPh 3 )] (R = Me, 2a ; Et, 2b ), whereas reaction of 1a and 1b with tertiary diphosphines gave mono‐ and dinuclear compounds, as appropriate, with the corresponding diphosphine acting as a monodentate ( 6b ), chelating ( 3a ) and bridging ligand ( 4a, 5a , 4b, 5b ). Treatment of 1a and 1b with (Ph 2 PCH 2 CH 2 PPh 2 )W(CO) 5 gave the new heterobimetallic complexes 7a and 7b . The crystal structures of complexes 3a and 4a are described.