Miguel A. Usón

Stereospecific reactions of the M(C6F5)2 (M=Pd or Pt) synthons towards cis-dithiolato complexes

Abstract Complexes of the general formula cis -[M(SC 6 F 5 ) 2 L 2 ] (M  Ni, Pd, or Pt; L 2  dppm [bis(diphenylphosphino)methane], dppe [ 1,2-bis(diphenylphosphino)ethane], or 2PPh 3 were synthesized by the reaction (1 : 2 between the corresponding cis -[MCl 2 L 2 ] and Tl(SC 6 F 5 ). When treated with cis -[M(C 6 F 5 ) 2 (THF) 2 ] (M  Pd or Pt; THF  OC 4 H 8 they yield geminal homo- or hetero-binuclear compounds, which were characterized by IR, NMR and mass spectroscopy.

Synthesis of group 10 polyfluorothiolate mono- and bi-nuclear complexes. Crystal structures of [Ni(SC6HF4)2(dppe)], [(dppe)Ni(μ-SC6HF4)2Pd(C6F5)2] and [(dppe)Ni(μ-SC6F5)2Pd(C6F5)2]

Complexes of the general formula cιs-[M(2,3,5,6-SC 6 HF 4 ) 2 (L-L)] (M = Ni, Pd, Pt; L-L = dppm [bis(diphenylphosphino)methane], dppe [1,2-bis(diphenylphosphino)ethane]) have been synthesized (yield >75%) by the reactioh (1:2) between the corresponding cis-[MCl 2 (L-L)] and Tl(SC 6 HF 4 ). These compounds, when treated with cis-[M(C 6 F 5 ) 2 (THF) 2 ] (M = Pd, Pt; THF = OC 4 H 8 ), quantitatively give rise to homo- or heterobinuclear compounds, (including two pairs of coordination position isomers). All of them have been characterized through IR, NMR and Mass spectrometries. The crystal structures of [Ni(SC 6 HF 4 ) 2 (dppe)]. [(dppe)Ni(μ-SC 6 HF 4 ) 2 Pd(C 6 F 5 ) 2 ] and [(dppe)Ni(μ-SC 6 F 5 ) 2 Pd(C 6 F 5 ) 2 ] have been determined, and the different interfacial π-π interactions between aromatic rings, which depend on the nature of the polyfluorothiolate ring, are analyzed.

Bis(perhalogenophenyl) derivatives of palladium(II) and platinum(II) containing S2CP(C6H11)3 as a mono- or bi-dentate ligand. Crystal structures of cis-[Pd(C6F5)2{S2CP(C6H11)3}] and cis-[Pt(C6F5)2{SC(S)P(C6H11)3}(CO)]

Addition of S2CP(C6H11)3 to solutions of [M(C6X5)2(OC4H8)2](M = Pd or Pt; X = F or Cl) affords the derivatives [M(C6X5)2{S2CP(C6H11)3}], which are the first containing S2CP(C6H11)3 chelate bonded to palladium or platinum. Reaction of the above complexes with 1 mol equivalent of a neutral monodentate ligand L leads to [M(C6X5)2{SC(S)P(C6H11)3}L](L = PPh3, X = F, M = Pd or Pt; L = CO, X = F or CI, M = Pt; L = pyridine, X = F, M = Pt) where S2CP(C6H11)3 is monodentate. The structure of one example of each of these types has been determined by single-crystal X-ray crystallography: cis-[Pd(C6F5)2{S2CP(C6H11)3}], space group C2/c, a= 26.654(8), b= 11.519(3), c= 24.223(7)A, β= 116.93(3)°, Z= 8, and R= 0.045; cis-[Pt(C6F5)2{SC(S)P(C6H11)3}(CO)], space group P, a= 9.864(2), b= 14.202(3), c= 14.638(5)A, α= 93.44(3), β= 103.11(2), γ= 105.45(2)°, Z= 2, and R= 0.042. The co-ordination at the metal atoms is planar. In the palladium derivative the chelating S2CP group makes a dihedral angle of 12.3° to the ligand plane; in the platinum derivative the corresponding angle formed by the monodentate ligand is 55.3°.

Polynuclear dithio- or trithiocarbonate-bridged complexes of palladium(II) and/or platinum(II). X-ray structure determination of [{(Ph2PCH2CH2PPh2)Pd(μ-S2CS)}2Pt(C6F5)2] · CH2Cl2

Abstract Trinuclear complexes [{(LL)M(μ-S 2 CS)} 2 M′(C 6 X 5 ) 2 ] with bridging CS 3 2− are obtained by the reaction of (LL)M(S 2 CS) (M  Pd, Pt; L 1,2-bis-(diphenylphosphino)ethane (dpe), 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane) with M′(C 6 X 5 ) 2 (OC 4 H 8 ) 2 (M′  Pd, Pt; X  F, Cl). The reaction between (LL)M(S 2 CO) and M′(C 6 F 5 ) 2 (OC 4 H 8 ) 2 yields (LL)M(μ-S 2 CO)-M′(C 6 F 5 ) 2 , the first compounds containing a dithiocarbonate bridging ligand. New compounds have been characterized by IR and 31 P NMR spectroscopy, and the molecular structure of [{(dpe)Pd(μ-S 2 CS)} 2 Pt(C 6 F 5 ) 2 ] established by a single crystal X-ray structure determination.

Anionic pentafluorothiophenolato complexes of palladium(II) or platinum(II)

Abstract By reacting TI(SC6F5) with halide containing complexes of palladium(II) or platinum(II), mono- or binuclear compounds with terminal and/or bridging pentafluorothiophenolato groups can be obtained. Treatment of the latter ones with triphenylphosphine causes bridge-cleavage affording cis-mononuclear compounds.

Single-bridged polynuclear pseudohalide complexes of palladium(II) and/or platinum(II)

Abstract By reacting MR 2 (THF) 2 or PtR 2 (CO) 2 (M = Pd, Pt; R = C 6 F 5 ; THF = OC 4 H 8 ) containing two (THF) or, respectively, one (CO) readily displaceable ligands, with monomeric palladium(II) complexes containing one potentially bridging ligand (CN, SCN), homo- or hetero-, bi- or trinuclear single bridged complexes can be synthesized. The reactions take place with stereoretention around the metal centres. Some isomers of the above described complexes have also been obtained by alternative routes.

Tri- and tetra-nuclear palladium(II) and/or platinum(II) compounds with double thiolato bridges. Crystal structure of [P(CH2Ph)Ph3]2[(C6F5)2Pd(µ-SC6F5)2Pt-(µ-SC6F5)2 Pt(µ-SC6F5)2Pd(C6F5)2]

The complexes cis-[M(C6F5)2(thf)2](M = Pd or Pt, thf = tetrahydrofuran) react (2:1) with [NMe4]2[M′(SC6F5)4][M′= Pd or Pt] or Q2[M′2(SC6F5)6][M′= Pd, Q = NBu4; M′= Pt, Q = NMe4 or P(CH2Ph)Ph3] to give homo- or hetero-metallic tri- or, respectively, tetra-nuclear dianions. The structure of the tetranuclear complex [P(CH2Ph)Ph3]2[(C6F5)2Pd(µ-SC6F5)2Pt(µ-SC6F5)2Pt(µ-SC6F5)2Pd(C6F5)2] has been established by single-crystal X-ray crystallography: the dianion possesses a crystallographic inversion centre; space group P, a= 12.247(2), b= 12.901 (2), c= 17.942(3)A, α= 84.47(2), β= 78.20(2), γ= 77.21 (2)°, Z= 1. and R= 0.0454. The co-ordination at the metal atoms is planar. The outer (palladium) planes form an angle of 28.20(11)° with the inner ones.

A general approach to the synthesis of neutral and cationic binuclear trithiocarbonato-bridged complexes of palladium(II) or of palladium(II)—platinum(II)

Addition (1:2) of Tl2CS3 to solutions of perchloratocomplexes of palladium(II) Pd(OClO3)(C6F5)(PR3) leads to neutral binuclear derivatives of the type (PR3)(C6F5)Pd(μ-S2CS)Pd(C6F5)(PR3)2, whilst the reaction of perchloratocomplexes of palladium(II) or platinum(II) with the neutral Pd(η2-CS3)(PR3)2 affords cationic complexes of the type [L2Pd(μ-S2CS)M(C6F5)L2]ClO4 (M = Pd or Pt). Spectral data (IR and 31P, NMR) permit the inequivocal structural characterization of both the neutral and the cationic complexes.

Neutral and cationic complexes containing η1 or η2 Ph3P+CMe2CS2− coordinated to a palladium, platinum or silver centre

The zwitterionic ligand Ph3P+CMe2CS2− forms neutral complexes with Pd(II) or Pt(II) as the metal centre, as well as cationic compounds of stoichiometries MX2L, MX2L(PPh3) (MPd, Pt; XCl, Br, I, C6F5) [Pd(C6F5)L(PEt3)2]ClO4, [AgL(PPh3)]ClO4, [AgL]x(ClO4)x and [AgL2]ClO4. Their structures have been assigned from analytical and spectroscopic (IR and 1H, 19F and 31P NMR) data.

Synthesis of cationic palladium(II) and platinum(II) complexes with a monodentate trialkylphosphoniumdithiocarboxylate ligand: molecular structure of trans-[Pd(C6F5)(PEt3)2(S2C–PEt3)]ClO4·CHCl3

Reaction of trans-[M(OClO3)(C6F5)(PR3)2] with the zwitterion S2C–PR′3 affords the complexes trans-[M(C6F5)(PR3)2(S2C–PR′3)]ClO4(M = Pd; R3= R′3= Et3, Bu3, or Et2Ph; R = Bu, R′= cyclo-C6H11; R = Ph, R′= Et or cyclo-C6H11 M = Pt, R = R′= Et or Bu). trans-[Pd(C6F5)(PEt3)2(S2C–PEt3)]ClO4 is also given by reaction of [Pd(C6F5)(PEt3)3]ClO4 with CS2. Reaction of [M(OClO3)(C6F5)(bipy)](bipy = 2,2′-bipyridyl) with S2C–PR′3 affords [M(C6F5)(bipy)(S2C–PR′3)]ClO4(M = Pd or Pt; R′= Et, Bu, or cyclo-C6A11). A crystallographic study of trans-[Pd(C6F5)(PEt3)2(S2C–PEt3)]ClO4(as its 1:1 chloroform solvate) shows that the cation contains a unidentate triethylphosphoniumdithiocarboxylate ligand, and 31P n.m.r. spectra of all products with two terminal phosphine ligands are consistent with trans stereochemistries. Crystals of trans-[Pd(C6F5)(PEt3)2(S2C–PEt3)]ClO4˙CHCl3 are monoclinic, space group P21/a, with a= 14.596 5(18), b= 15.356(3), c= 19.324 2(16)A, β= 109.257(8)°, and Z= 4. Using 4 093 amplitudes the structure has been refined to R= 0.1049. The non-bonding Pd ⋯ S distance is 3.644(4)A.