Novel Cyclometallated Complexes Derived From a Halogenated Thiosemicarbazone. Crystal and Molecular Structures of 2‐FC 6 H 4 C(Me)=NN(H)C(=S)NHPh and[(Pd{2‐FC 6 H 3 C(Me)=NN=C(S)NHPh}) 2 (μ‐PPh 2 (CH 2 ) 2 PPh 2 )]

Treatment of the thiosemicarbazone 2‐FC 6 H 4 C(Me)=NN(H)C(=S)NHPh, a , with palladium(II) acetate in acetic acid, or with lithium tetrachloropalladate(II) in methanol, gave the tetranuclear cyclometallated complex [Pd{2‐FC 6 H 3 C(Me)=NN=C(S)NHPh}] 4 (1a) . Reaction of 1a with the diphosphines Ph 2 P(CH 2 ) 2 PPh 2 (dppe), Ph 2 PCH=CHPPh 2 ( trans ‐dpe) Ph 2 P(CH 2 ) 3 Ph 2 (dppp) or Ph 2 P(CH 2 ) 4 Ph 2 (dppb) in a 1:2 molar ratio gave the dinuclear cyclometallated complexes [(Pd{2‐FC 6 H 3 C(Me)=NN=C(S)NHPh}) 2 (μ‐Ph 2 P(CH 2 ) n PPh 2 )], (n = 2, 2a ; 3, 4a ; 4, 5a ) and [(Pd{2‐FC 6 H 3 C(Me)=NN=C(S)NHPh}) 2 (μ‐Ph 2 PCH=CHPPh 2 )], ( 3a ). The X‐ray crystal structure of ligand a and of complex 2a are described. The structure of complex 2a shows the palladium atom is bonded to four different donor atoms: C, N, S and P.