Antonio Suárez

New cyclometallated platinum(II) compounds with thiosemicarbazones: crystal and molecular structure of [Pt{4-MeC6H3C(Me)NNC(S)NH2}(PPh3)]

Abstract Treatment of the thiosemicarbazones 3-CH3(CH2)5OC6H4C(Me)NN(H)C(S)NH2 (a), 4-MeC6H4C(Me)NN(H)C(S)NH2 (b), C6H5C(Et)NN(H)C(S)NH2 (c), C6H5C{CH3(CH2)10}NN(H)C(S)NH2 (d) and 4-MeC6H4C(Me)NN(H)C(S)NHMe (e) with K2[PtCl4] gives tetranuclear platinum(II) compounds 1a–1e with deprotonation of the NH group and with the ligand acting as a terdentate [C,N,S] moiety. Reaction of 1a–1e with PPh3 and of 1a with P(4-MeOC6H4)3 yielded mononuclear species 2a–2e and 3a, respectively. Treatment of 1a with the diphosphines Ph2PCH2PPh2 (dppm), Ph2P(CH2)2PPh2 (dppe), Ph2P(CH2)3PPh2 (dppp), Ph2P(CH2)4PPh2 (dppb), Ph2P(CH2)5PPh2 (dpppe), Ph2P(CH2)6PPh2 (dpph), and 1,1′-ferrocenebis(diphenylphosphine) (dppf) gives dinuclear compounds 4a–10a. In all cases the PdSchelating bond is strong enough to withstand reaction with the phosphorus ligands without bond cleavage. The molecular structure of 2b has been determined by X-ray crystallography. Mononuclear units are held together by hydrogen bonding, forming dimers in the solid state.

Influence of phenyl ring substituents in the cyclometallation of Schiff base ligands: crystal and molecular structures of [Pd-{3,4-(OCH2O)C6H2C(H)N(Cy)-C2,N}(μ-O2CMe)]2 and [Pd-{3,4-(OCH2CH2O)C6H2C(H)N(Cy)-C6,N}(μ-O2CMe)]2

Abstract Reaction of Pd(OAc)2 with the Schiff base ligands 3,4-{O(CH2)nO}C6H3C(H)NR (n=1, 2; R=Cy, 3,4-(OCH2O)C6H3CH2-) leads to dinuclear cyclometallated products in which each palladium atom is C,N bonded to a deprotonated organic ligand, and to two acetate groups which bridge both metal centers. Treatment of 3,4-{O(CH2)2O}C6H3C(H)NCH2CH2NMe2 with [PtMe2(COD)] gives mononuclear compounds with the ligand as terdentate through the [C, N, N] atoms. The regioselectivity of the cyclometallation processes is discussed by 1H-NMR spectroscopy and X-ray diffraction studies.

Novel structures of cyclometallated complexes of palladium(II) derived from terdentate ligands. Crystal and molecular structure of [Pd{C6H4C(H)NCH2CH2CH2NMe2}(X)] (X=Cl, Br, I)

Abstract Treatment of N-(2-chlorobenzylidene)-N,N-dimethyl-1,3-propanediamine (1) and N-(2-bromo-3,4-(MeO)2-benzylidene)-N,N-dimethyl-1,3-propanediamine (20) with tris(dibenzylideneacetone)dipalladium(0) in toluene gave the mononuclear cyclometallated complexes [Pd{C6H4C(H)NCH2CH2CH2NMe2}(Cl)] (2) and [Pd{3,4-(MeO)2C6H2C(H)NCH2CH2CH2NMe2}(Br)] (21), respectively, via oxidative addition reaction with the ligand as a C,N,N terdentate ligand. Reaction of 2 with sodium bromide or iodide in an acetone–water mixture gave the cyclometallated analogues of 2, [Pd{C6H4C(H)NCH2CH2CH2NMe2}(Br)] (3) and [Pd{C6H4C(H)NCH2CH2CH2NMe2}(I)] (4), by halogen exchange. The X-ray crystal structures of 2, 3 and 4 were determined and discussed. Treatment of 2, 3, 4 and 21 with tertiary monophosphines in acetone gave the mononuclear cyclometallated complexes [Pd{C6H4C(H)NCH2CH2CH2NMe2}(L)(X)] (6: L=PPh3, X=Cl; 7: L=PPh3, X=Br; 8: L=PPh3, X=I; 9: L=PMePh2, X=Cl; 10: L=PMe2Ph, X=Cl) and [Pd{3,4-(MeO)2C6H2C(H)NCH2CH2CH2NMe2}(L)(Br)] (22: L=PPh3; 23: L=PMePh2; 24: L=PMe2Ph). A fluxional behaviour due to an uncoordinated CH2CH2CH2NMe2 could be determined by variable temperature NMR spectroscopy. Treatment of 2, 3 and 4 with silver trifluoromethanesulfonate followed by reaction with triphenylphosphine gave the mononuclear complex [Pd{C6H4C(H)NCH2CH2CH2NMe2}(PPh3)][F3CSO3] (11) where the Pd–NMe2 bond was retained. Reaction of 2, 3 and 4 with ditertiary diphosphines in a cyclometallated complex–diphosphine 2:1 molar ratio gave the binuclear complexes [{Pd[C6H4C(H)NCH2CH2CH2NMe2](X)}2(μ-L–L)][L–L=PPh2(CH2)4PPh2(dppb) (13, X=Cl; 14, X=Br; 15, X=I; L–L=PPh2(CH2)5PPh2(dpppe): 16, X=Cl; 17, X=Br; 18, X=I) with palladium–NMe2 bond cleavage. Treatment of 2, 3 and 4 with ditertiary diphosphines, in a cyclometallated complex–diphosphine 2:1, molar ratio and AgSO3CF3 gave the binuclear cyclometallated complexes [{Pd[C6H4C(H)NCH2CH2CH2NMe2]}2(μ-L–L)][F3CSO3]2 (11: L–L=PPh2(CH2)4PPh2(dppb), X=Cl; 12: L–L=PPh2(CH2)5PPh2 (dpppe), X=Cl). Reaction of 2 with the ditertiary diphosphine cis-dppe in a cyclometallated complex–diphosphine 1:1 molar ratio followed by treatment with sodium perchlorate gave the mononuclear cyclometallated complex [Pd{C6H4C(H)NCH2CH2CH2NMe2}(cis-PPh2CHCHPPh2–P,P)][ClO4] (19).

Cyclopalladated compounds derived from a [C,N,S] terdentate ligand: synthesis, characterization and reactivity. Crystal and molecular structures of [Pd{2-ClC6H3C(H)NCH2CH2SMe}(Cl)] and [{Pd[2-ClC6H3C(H)NCH2CH2SMe]}2{μ-Ph2P(CH2)4PPh2}][CF3SO3]2

Treatment of the Schiff base 2-ClC6H4C(H)NCH2CH2SMe, 1, with palladium(II) acetate in dry toluene gave the mononuclear cyclometallated complex [Pd{2-ClC6H3C(H)NCH2CH2SMe}(O2CMe)], 2. Reaction of 2 with aqueous sodium chloride gave [Pd{2-ClC6H3C(H)NCH2CH2SMe}(Cl)], 3, after a metathesis reaction. The X-ray crystal structure of 3 was determined and shows that the palladium atom is bonded to four different donor atoms: C, N, S and Cl. Treatment of 3 with triphenylphosphine in acetone gave the mononuclear cyclometallated complex [Pd{2-ClC6H3C(H)NCH2CH2SMe}(Cl)(PPh3)] with cleavage of the Pd–S bond. However, treatment of 3 with silver triflate and triphenylphosphine gave [Pd{2-ClC6H3C(H)NCH2CH2SMe}(PPh3)][CF3SO3], 10, in which the Pd–S bond is retained. Reaction of 3 with the diphosphines dppm, dppb or dppf in a 2 : 1 molar ratio gave the dinuclear cyclometallated complexes [{Pd[2-ClC6H3C(H)NCH2CH2SMe](Cl)}2{μ-Ph2P(CH2)nPPh2}], (n=1, 5; n=4, 6), and [{Pd[2-ClC6H3C(H)NCH2CH2SMe](Cl)}2(μ-Ph2PC5H4FeC5H4PPh2)], 7. Treatment of 3 with dppb in a 2 : 1 molar ratio and AgCF3SO3 gave the dinuclear cyclometallated complex [{Pd[2-ClC6H3C(H)NCH2CH2SMe]}2{μ-Ph2P(CH2)4PPh2}][CF3SO3]2, 11, which was characterized by X-ray crystal structure analysis. Reaction of 3 with dppe in a 1 : 1 molar ratio and sodium perchlorate gave the mononuclear complex [Pd{2-ClC6H3C(H)NCH2CH2SMe}{Ph2P(CH2)2PPh2-P,P}][ClO4], 8. Treatment of 3 with bis(2-diphenylphosphinoethyl)phenylphosphine in a 1 : 1 molar ratio, followed by treatment with sodium perchlorate gave [Pd{2-ClC6H3C(H)NCH2CH2SMe}{(Ph2PCH2CH2)2PPh-P,P,P}][ClO4], 9, in which the triphosphine is bonded to the palladium atom through the three phosphorus atoms.

Synthesis and reactivity of novel cyclometallated complexes derived from [C,N,O] terdentate ligands. Crystal structure of [Pd{2,3,4-(MeO)3C6HC(H)N[2-(O)C6H4]}(PPh3)]

Treatment of the Schiff base ligands 2,3,4-(MeO)3C6H2C(H)N[2-(OH)C6H4], a, and 2,3,4-(MeO)3C6H2C(H)N[2-(OH)-4-MeC6H4], b, with palladium(II) acetate in toluene gave the cyclometallated complexes [Pd{2,3,4-(MeO)3C6HC(H)N[2-(O)C6H4]}]n, 1a, and [Pd{2,3,4-(MeO)3C6HC(H)N[2-(O)-4-MeC6H4]}]n, 1b, respectively, as air stable solids, with the [C,N,O] ligand terdentate after deprotonation of the –OH group. Reaction of the cyclometallated complexes with triphenylphosphine gave the mononuclear species [Pd{2,3,4-(MeO)3C6HC(H)N[2-(O)C6H4]}(PPh3)], 2a, and [Pd{2,3,4-(MeO)3C6HC(H)N[2-(O)-4-MeC6H4]}(PPh3)], 2b, with cleavage of the polynuclear structure. The molecular structure of 2a has been determined by X-ray crystallography. Treatment of 1a and 1b with the diphosphines dppm, dppp, dppb, dpppe and dppf in a 1∶2 molar ratio afforded the dinuclear cyclometallated complexes [(Pd{2,3,4-(MeO)3C6HC(H)N[2-(O)C6H4]})2{μ-PPh2(CH2)nPPh2}] (3a: n = 1; 4a: n = 3; 5a: n = 4; 6a: n = 5), [(Pd{2,3,4-(MeO)3C6HC(H)N[2-(O)C6H4]})2(μ-PPh2C5H4FeC5H4PPh2)], 7a, [(Pd{2,3,4-(MeO)3C6HC(H)N[2-(O)-4-MeC6H4]})2{μ-PPh2(CH2)nPPh2}] (3b: n = 3; 4b: n = 4) and [(Pd{2,3,4-(MeO)3C6HC(H)N[2-(O)-4-MeC6H4]})2(μ-PPh2C5H4FeC5H4PPh2)], 5b, as air stable solids. Treatment of 1a and 1b with an excess of mono- or diphosphine did not produce cleavage of the Pd–Ochelating bond.

The First Crystal and Molecular Structure of asyn-Acetato-Bridged Dinuclear Cyclometallated Complex [Pd{2,3,4-(MeO)3C6HC(H)=NCH2CH2OH}(μ-OAc)]2

Treatment of the Schiff base ligands 2,3,4-(MeO)3C6H2C(H)=NR (R = CH2CH2OH, 1; R = Me, 17; R = Et, 18; R = Pr, 19; R = tBu, 20) with palladium(II) acetate in toluene gave the dinuclear cyclometallated complexes [Pd{2,3,4-(MeO)3C6HC(H)=NR}(μ-O2CMe)]2 (R = CH2CH2OH, 2; R = Me, 21; R = Et, 22; R = Pr, 23; R = tBu, 24), with the ligand bonded to the palladium atom through the imine nitrogen and the C6 carbon atoms. The 1H and 13C{1H} NMR spectra of the complexes showed the presence of the anti and syn isomers in solution. The anti/syn ratio varies with the solvent and the nature of the imine nitrogen substituent R. Complex 24 with the bulky tBu group showed a 28:1 ratio in chloroform whilst the less bulky substituted complexes showed lower ratios. The X-ray crystal structure of the syn isomer of complex 2 is described. Reaction of the acetato-bridged complex 2 with PPh3 gave the mononuclear complex 4, in a bridge-splitting reaction. Reaction of 2 with the diphosphanes dppm, dppp and dppb in a 1:1 molar ratio gave the dinuclear cyclometallated complexes 5, 6 and 7, respectively. Treatment of 2 with an aqueous solution of sodium chloride gave the chloro-bridged complex 3. Treatment of the cyclometallated chloro-bridged complex 3 with PPh3 in acetone yielded the mononuclear complex 8, and reaction of 3 with silver triflate gave the cyclometallated complex 9, with the palladium atom bonded to four different atoms C, N, O and P. Treatment of 3 with the tertiary diphosphanes dppp, dppb and dppf, in a 1:1 molar ratio gave the dinuclear complexes 10, 11 and 12, respectively, with terminal chloride ligands. However, reaction of 3 with the small “bite” diphosphane dppm gave 13, with a bridging chloride ligand. Reaction of 11 with silver triflate in acetone gave the new dinuclear complex 14, with the Schiff base ligand as [C,N,O] terdentate. Reaction of 3 with the diphosphane dppe in a 1:2 molar ratio, and silver perchlorate, gave the mononuclear complex 15. Treatment of 3 with the triphosphane bis(2-diphenylphosphanylethyl)phenylphosphane in a 1:2 molar ratio, followed by treatment with sodium perchlorate, gave 16, in which the palladium atom was bonded to the triphosphane through the three phosphorus atoms. The X-ray crystal structures of complexes 8, 9, 15 and 16 are also reported. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

Polynuclear cyclometallated palladium (II) complexes derived from potentially hexadentate Schiff base ligands. Crystal structures of [(Cl)Pd{Me2NCH2CH2N(H)C}C6H2{C(H)NCH2CH2NMe2}Pd(Cl)] and [{(Ph2PCH2CH2)2PPh-P,P,P}Pd{Me2NCH2CH2N(H)C}C6H2{C(H)NCH2CH2NMe2}Pd{(Ph2PCH2CH2)2PPh-P,P,P}][Cl]2

Abstract The oxidative addition reaction of 1,4-(CN(H)CH2CH2Me2)2-2,5-Cl2C6H2 with tris(dibenzylideneacetone)dipalladium(0) in benzene gave the doubly cyclometallated compound [(Cl)Pd{Me2NCH2CH2N(H)C}C6H2{C(H)NCH2CH2NMe2}Pd(Cl)] (1) with each palladium atom C,N,N′ bonded to the ligand. Treatment of 1 with thallium acetylacetonate gave the dinuclear cyclometallated complex 2 with two chelating acetylacetonate ligands. Reaction of 1 with tertiary monophosphines in a 1–phosphine 1:2 molar ratio gave dinuclear cyclometallated complexes 3–7, in which the palladiumNMe2 bond has been broken, whereas treatment of 1 with silver perchlorate, followed by reaction with PPh3 in a 1–phosphine 1:2 molar ratio gave cyclometallated complex 4 where the ligand remains C,N,N′ bonded and the chloride ligand has been substituted by triphenylphosphine. Treatment of 1 with tertiary diphosphines leads to dinuclear compounds 8, 10 and 11, whilst previous treatment of 1 with silver perchlorate followed by the diphosphine 1,4-bis(diphenylphosphino)butane (dppb) in a 1–diphosphine 1:1 molar ratio yielded the tetranuclear complex 9. Reaction of 1 with the tertiary triphosphine bis(2-diphenylphosphinoethyl)phenylphosphine in 1:2 molar ratio gave the complex [{(Ph2PCH2CH2)2PPh-P,P,P}Pd{Me2NCH2CH2N(H)C}-C6H2{C(H)NCH2CH2NMe2}Pd{(Ph2PCH2CH2)2PPh-P,P,P}][Cl]2 (12) in which both palladium atoms are pentacoordinated. The crystal structures of 1 and 12 are described.

Reactivity of cyclometallated semicarbazone complexes of Pd(II): crystal and molecular structures of [Pd{C6H4C(Et)NN(H)C(O)NH2}(PPh3)][ClO4] and [Pd{C6H4C(Et)NN(H)C(O)NH2}{(Ph2PCH2CH2)2PPh-P,P,P}][Cl]

Treatment of the cyclometallated complexes [Pd{4-MeC 6 H 3 C(Me)NN(H)C(O)NH 2 }(Cl)] ( a ), [Pd{C 6 H 4 C(Et)NN(H)C(O)NH 2 }(Cl)] ( b ) and [Pd{3,4-Me 2 C 6 H 2 C(Me)NN(H)C(O)NH 2 }(Cl)] ( c ) with tertiary monophosphine ligands in a complex–phosphine 1:1 molar ratio yielded [C, N] bonded cyclometallated complexes [Pd{4-MeC 6 H 3 C(Me)NN(H)C(O)NH 2 }(Cl)(L)] ( 1a – 4a ), [Pd{C 6 H 4 C(Et)NN(H)C(O)NH 2 }(Cl)(L)] ( 1b – 4b ) and [Pd{3,4-Me 2 C 6 H 2 C(Me)NN(H)C(O)NH 2 }(Cl)(L)] ( 1c – 4c ), [L=PPh 3 , PMePh 2 , PEtPh 2 and PEt 2 Ph]. Reaction of a , b and c with silver perchlorate, prior to the treatment with the monophosphine gave the [C, N, O] bonded cyclometallated complexes [Pd{4-MeC 6 H 3 C(Me)NN(H)C(O)NH 2 }(L)][ClO 4 ] ( 5a – 8a ), [Pd{C 6 H 4 C(Et)NN(H)C(O)NH 2 }(L)][ClO 4 ] ( 5b – 8b ) and [Pd{3,4-Me 2 C 6 H 2 C(Me)NN(H)C(O)NH 2 }(L)][ClO 4 ] ( 5c – 8c ). Reaction of a , b and c with tertiary monophosphines in a complex–phosphine 1:2 ratio gave the C only bonded non-cyclometallated complexes [Pd{4-MeC 6 H 3 C(Me)NN(H)C(O)NH 2 }(PEt 2 Ph) 2 (Cl)] ( 9a ), [Pd{C 6 H 4 C(Et)NN(H)C(O)NH 2 }(PPh 3 ) 2 (Cl)] ( 9b ) and [Pd{3,4-Me 2 C 6 H 2 C(Me)NN(H)C(O)NH 2 }(PEt 2 Ph) 2 (Cl)] ( 9c ). Treatment of a , b and c with the triphosphine bis(2-diphenylphosphinoethyl)phenylphosphine (trifos) yielded the non-cyclometallated complexes [Pd{4-[MeC 6 H 3 C(Me)NN(H)C(O)NH 2 }{L- P , P , P }][Cl] ( 10a ), [Pd{C 6 H 4 C(Et)NN(H)C(O)NH 2 }{L- P , P , P }][Cl] ( 10b ) and [Pd{3,4-Me 2 C 6 H 2 C(Me)NN(H)C(O)NH 2 }{L- P , P , P }][Cl] ( 10c ) (L=(Ph 2 PCH 2 CH 2 ) 2 PPh). The complexes were characterised by their elemental analysis (C, H, N) and by IR and 31 P-{ 1 H} and 1 H-NMR spectroscopy. [Pd{C 6 H 4 C(Et)NN(H)C(O)NH 2 }(PPh 3 )][ClO 4 ] ( 5b ) and [Pd{C 6 H 4 C(Et)NN(H)C(O)NH 2 }{(Ph 2 PCH 2 CH 2 ) 2 PPh- P , P , P }][Cl] ( 10b ) were characterised crystallographically.

Cyclometallated complexes of palladium(II) with 1-methyl-2-phenylimidazole and tertiary diphosphines. Crystal and molecular structure of [Pd[o-C6H4C=NC(H)=C(H)NMe](Ph2PCH(Me)PPh2-P,P)][PF6]

Abstract Treatment of Pd(AcO) 2 with 1-methyl-2-phenylimidazole, and subsequent treatment with sodium chloride or sodium bromide gave the corresponding halide-bridged cyclometallated complexes [Pd o -C 6 H 4 C=NC(H)=C(H)NMe( μ -X)] 2 ( 2 , X = Cl; 3 , X = Br). Complexes 2 and 3 react with tertiary diphosphines in a 1:1 molar ratio to give dinuclear cyclometallated compounds with bridging diphosphine and halogen ligands [Pd o -C 6 H 4 C=NC(H)=C(H)NMe( μ -L-L)( μ -X)]X ( 4–9 ) or with only bridging diphosphine ligands [Pd o -C 6 H 4 C=NC(H)=C(H)NMe( μ -L-L)(X) 2 ] ( 10–17 ), [X = Cl, Br; L-L = Ph 2 PCH 2 PPh 2 (dppm), Ph 2 PC(=CH 2 )PPh 2 (vdpp), Ph 2 PCH(CH 3 )PPh 2 (1,1-dppe), trans -Ph 2 P(CH=CH)PPh 2 ( trans -dppe), Ph 2 P(CH 2 ) 2 PPh 2 (dppe), Ph 2 P(CH 2 ) 3 PPh 2 (dppp), Ph 2 P(CH 2 ) 4 PPh 2 (dppb), as appropriate]. When the reaction is carried out in a 1:2 molar ratio and in the presence of NH 4 PF 6 or NaClO 4 , mononuclear cyclometallated compounds with a chelating diphosphine ligand are obtained [Pd o -C 6 H 4 C=NC(H)=C(H)NMe(L-L-P,P)][Y] ( 18–27 ) [Y = PF 6 , ClO 4 ; L-L = Ph 2 PCH 2 PPh 2 (dppm), Ph 2 PC(=CH 2 )PPh 2 (vdpp), Ph 2 PCH(CH 3 )PPh 2 (1,1-dppe), Ph 2 PN(CH 3 )PPh 2 (dppma), cis -Ph 2 P(CH=CH)PPh 2 ( cis -dppe), Ph 2 P(CH 2 ) 2 PPh 2 (dppe), Ph 2 P(CH 2 )PPh 2 (dppp), Ph 2 P(CH 2 ) 4 PPh 2 (dppb)]. Compounds 18–22 and 25–27 could also be obtained by reaction of complexes 4–17 with the appropriate diphosphine and NH 4 PF 6 or NaClO 4 . The diphosphines dppma and cis -dppe failed to behave as bridging ligands and only gave mononuclear compounds. The complexes were characterized by their elemental analysis (C, H, N) and by IR and 31 P- 1 H and 1 H NMR data. The X-ray crystal structure of complex 22 is described.

Polynuclear cyclometallated palladium(II) complexes. Crystal and molecular structures of [(PPh3)(Cl)PdN(Cy)C(H)C6H2C(H)N(Cy) Pd(Cl)(PPh3)] and [{PdN(Cy)C(H)C6H2C(H)N(Cy)Pd}{Ph2PC(H)C(H)PPh2-P,P}2][ClO4]2

Abstract Treatment of N , N -terephthalylidenebis(cyclohexylamine) ( L ) with palladium(II) acetate in toluene at room temperature gave the dicyclometallated acetato-bridged complex [(OAc)PdN(Cy)C(H)C 6 H 2 C(H)N(Cy)Pd(OAc)] n ( 1 ). Reaction of 1 with lithium chloride or bromide in acetone produced the chloro- or bromo-bridged complexes [(Cl)PdN(Cy)C(H)C 6 H 2 C(H)N(Cy)Pd(Cl)] n ( 2 ) and [(Br)PdN(Cy)C(H)C 6 H 2 C(H)N(Cy)Pd(Br)] n ( 3 ), respectively. Reaction of 2 with triphenylphosphine gave [(PPh 3 )(Cl)PdN(Cy)C(H)C 6 H 2 C(H)N(Cy)Pd(Cl)(PPh 3 )] ( 4 ). Treatment of 2 and 3 with bis(diphenylphosphino)methane and 1,5-bis(diphenylphosphino)pentane in a 1:1 molar ratio afforded [{(Cl)PdN(Cy)C(H)C 6 H 2 C(H)N(Cy)Pd(Cl)} 2 {μ-Ph 2 PCH 2 PPh 2 } 2 ] ( 5 ) and [{(Br)PdN(Cy)C(H)C 6 H 2 C(H)N(Cy)Pd(Br)} 2 {μ-Ph 2 P(CH 2 ) 5 PPh 2 } 2 ] ( 6 ), respectively. Reaction of 2 and 3 with bis(diphenylphosphino)methane or cis -1,5-bis(diphenylphosphino)ethene, in a 1:2 molar ratio, and sodium perchlorate, gave dinuclear cyclometallated compounds with two chelated phosphine ligands [{PdN(Cy)C(H)C 6 H 2 C(H)N(Cy)Pd}{Ph 2 PCH 2 PPh 2 - P , P } 2 ][ClO 4 ] 2 ( 7 ) and [{PdN(Cy)C(H)C 6 H 2 C(H)N(Cy)Pd}{Ph 2 PC(H)C(H)PPh 2 - P , P } 2 ][ClO 4 ] 2 ( 8 ). The compounds have been fully characterized by elemental analysis, mass spectrometry, IR and NMR spectroscopy, and complexes 4 and 8 by X-ray crystallography.