The First Cyclometallated (1‐Ferrocenylethanone thiosemicarbazone)palladium( II ) Compounds − Crystal and Molecular Structure of [Pd{(η 5 ‐C 5 H 5 )Fe(η 5 ‐C 5 H 3 )C(Me)=NN=C(S)NHMe}(PPh 3 )]

Treatment of the 1‐ferrocenylethanone thiosemicarbazone ligands (η 5 ‐C 5 H 5 )Fe(η 5 ‐C 5 H 4 )C(Me)=NN(H)C(=S)NHR [R = H ( a ), Me ( b )] with K 2 [PdCl 4 ] gave the novel heterometallic octanuclear palladium( II ) compounds [Pd{(η 5 ‐C 5 H 5 )Fe(η 5 ‐C 5 H 3 )C(Me)=NN=C(S)NHR}] 4 [R = H ( 1a ), Me ( 1b )] as tetramers, after deprotonation of the NH group, with the ligands acting as terdentate donors through the [C,N,S] atoms. Treatment with nucleophiles cleaves the tetrameric clusters giving compounds in which splitting only of the Pd−S bridging bonds has occurred. The strength of the Pd−S chelating bond hinders its cleavage. Thus, treatment of 1a or 1b with Ph 2 P(CH 2 ) n PPh 2 [ n = 2 (dppe), 3 (dppp), 4 (dppb)] in a 1:2 molar ratio gave the tetranuclear species 2a − 4a and 2b − 4b , respectively, and treatment with PPh 2 R gave the dinuclear compounds 5a − 7a and 5b − 6b [R = Ph ( 5a , 5b ), Et ( 6a , 6b ), Me ( 7a )]. The complexes described are the first fully characterized cyclometallated palladium( II ) complexes with 1‐ferrocenylethanone thiosemicarbazone ligands. The crystal and molecular structure of compound 5b have been determined by X‐ray crystallography. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)