Sanjay Narayan

Synthesis and characterization of cyclometallated palladium(II) dithiolate complexes of the type [Pd(E ∩ C)(C ∩ S)]

Abstract Cyclometallated palladium(II) dithiolate complexes of the type [Pd(E ∩C)(S ∩ S)] (where E ∩ CH N,N′ -dimethylbenzylamine, azobenzene, 4-MeOC 6 H 4 CH  NC 6 H 4 Me-4, 2-phenylpyridine or tris- o -tolylphosphine; S ∩ S  S 2 CNEt 2 or S 2 P(OR) 2 , R  Et, Pr n , Pr i , Bu n or Bu s ) have been synthesized by the reaction of [Pd(E ∩ C)(μ−X)] 2 (XCl, OAc) with sodium or ammonium salts of dithio acids. These complexes were characterized by elemental analysis. IR, NMR ( 1 H and 31 P) and mass spectral data. Treatment of [Pd(N ∩ C){S 2 P(OPr n ) 2 }] [N ∩ C  NC 5 H 4 C 6 H 4 or N(Ph)NC 6 H 4 ] with anhydrous HCl in diethyl ether afforded [Pd(E ∩ C)(μ−Cl)] 2 and the free dithio acid. When reaction was carried out with triphenylphosphine, a dynamic equilibrium was established between [Pd(N ∩ C){S 2 P(OPr n ) 2 }] and [Pd(PPh 3 )( η 1 −CN){S 2 P(OPr n ) 2 }]. The crystal structure of [P d{N(Me) 2 CH 2 C 6 H 4 }{S 2 P(OPr n ) 2 }] ( 3 ) has been determined by X-ray diffraction. The compound exhibits distorted square-planar geometry around palladium atom.

Synthesis and characterization of monomeric palladium(II) pyridine-2-chalcogenolate complexes

Abstract Mononuclear palladium(II) complexes of the type [Pd(Epy)(S∩S)(PPh3)] [E=S or Se; S∩S=S2CNEt2, S2P(OR)2 (R=Et, Prn, Pri)] have been prepared. All the complexes have been characterized by elemental analysis and NMR (1H, 31P{1H}, 77Se{1H}) spectral data. The NMR data indicate that there are two species in solution, i.e. one with chelating S∩S ligand predominates (∼95%) while the other with chelating Epy and monodentate S∩S existing in ∼5% concentration. The X-ray crystal structure of [Pd(Spy){S2P(OPri)2}(PPh3)] has been determined. The square planar palladium atom is coordinated to asymmetrically chelated (PriO)2PS2− ligand, PPh3 and pyS− groups.

Synthesis and structural characterization of chalcogenido-bridged trinuclear palladium(II) dialk ldithiophosphates, [Pd3(μ3-E)2 {S2(OR)2}2(PR3′)2] (E = S or Se, R = Et, Prn, Pri, Bus and R′ = Ph, Et)

Abstract Reaction of [PdCl{S2P(OR)2}(PR′3)] with sodium sulfide or selenide in acetone afforded neutral trinuclear palladium(II) complexes of the type [Pd3(μ3-E)2{S2P(OR)2}2(PR′3)2] (E = S or Se; R = Et, Prn Pri, Bus, R′ = Et or Ph) in 24–42% yield. These complexes were characterized by elemental analysis, NMR (1H, 31P, 77Se) and FAB mass spectral data. The molecular structure of [Pd3(μ3-S)2{S2P(OEt)2}2(PPh3)2] (1) was determined by X-ray diffraction. The molecule consists of three distorted square-planar palladium atoms sharing two μ3-S ligands. One of the palladium atoms is linked with two triphenylphosphine ligands while each of the remaining two palladium atoms is coordinated with chelating dithiophosphate group.

Multinuclear complexes containing [Pt2(μ-S)2(Ptolyl3)4] as a metallo-ligand

Treatment of [PtCl2(Ptolyl3)2] (tolyl = 4-MeC6H4) with Na2S in benzene gave [Pt2(μ2-S)2(Ptolyl3)4] (1), which is soluble in common organic solvents. Reactions of (1) with various metal complexes have been studied and several polynuclear metal aggregates isolated. These new complexes were characterized by elemental analysis and n.m.r. spectroscopy.

Platinum(II) pyridine-2-thiolate and -selenolate complexes

The reaction of [Pt2X2(μ-Cl)2(PR3)2] with NaSpy or NaSepy gave complexes of the type [PtX(Epy)(PR3)]n (X=Cl or Ar; E=S or Se; PR3=PEt3, PMe2Ph, PMePh2 or PPh3; n=1 or 2) which were characterized by elemental analysis and by 1H, 31P{1H}, 195Pt{1H} n.m.r. spectroscopy. When X=Cl a dynamic equilibrium between [Pt2Cl2(μ-Spy)2(PR3)2] and [PtCl(k-S,N-Spy)(PR3)] species exists in CHCl3 solution. The aryl derivatives, X=Ar, exist exclusively as dimers (n=2) with predominantly S∩N bridging. The [Pt(Spy)2 (PPh3)2] complex, prepared by reacting [PtCl2 (PPh3)2] with NaSpy, dissociates in CHCl3 to [Pt(k-S,N-Spy) (Spy)(PPh3)] and PPh3 at room temperature.

Synthesis and characterization of methylpalladium(II) dithiolate complexes of the type [PdMe(S⌢S)(ER3)] (S⌢S = S2CNR 2, S2COEt, S2P(OR)2, S2 PPh2; ER3 = PMePh2, PPh3, AsPh3)

Methylpalladium(II) dithiolate complexes of the type [PdMe(S⌢S)(ER3] (S⌢S = S2 CNR2 (R = Me or Et), S2COEt, S2P(OR)2 (R = Et, nPr, iPr), S2PPh2; ER3 = PMePh2, PPh3, AsPh3) have been synthesized by the reaction of [Pd2Me2(μ-Cl)2(PMePh2)2] with sodium/potassium/ammonium salts of the dithio acid or by treatment of [PdMeCl(cod)] with ER3 followed by sodium/potassium/ammonium salts of the dithio ligand. All the complexes were characterized by elemental analysis, IR and nuclear magnetic resonance (1H, 31P) data.

Chloro(diethyl dithiophosphato-S, S')(triphenylphosphine-P)palladium(II)

The structure of the title compound, [PdCl(C 4 H 10 O 2 PS 2 )(C 18 H 15 P)], is reported. There are two independent molecules in the asymmetric unit. The coordination around the Pd atom in each molecule is distorted square planar. Both molecules have nearly the same conformation, except for the orientation of the ethyl groups on the dithiophosphate ligand. Bond lengths and angles are typical of related Pd and Pt complexes.

Binuclear platinum(II) complexes of the type [Pt2Cl2(μ-L)(μ-pz) (PR3)2] [L=SC5H4N or S2P(OR′)2]

Binuclear platinum complexes of general formula [Pt2Cl2(μ-L)(μ-pz)(PR3)2] [L = 2-Spy, py = pyridyl, S2P(OR′)2 (R′ = Et or i-Pr); pz = pyrazolate; PR3 = PEt3, PMe2Ph or PMePh2] have been synthesized. They adopt a cis configuration in which the phosphine ligands are trans to the single atom bridging ligand, L.