M. Teresa Moreno

Synthesis of mono- and polynuclear perhalophenyl palladium-platinum acetylide complexes. Molecular structure of (NBu4)2[Pt2Ag2(C6F5)4(CCPh4] · 4CH2Cl2

Abstract The reaction between [Ag(CCR)]n (R = tBu, Ph) and the appropriate mononuclear palladium or platinum substrate affords mononuclear derivatives of the type [M(C6F5)(CCR)L2] (M = Pd, Pt; R = tBu, Ph; L = PPh3, dppe). Polynuclear (NBu4)2[Pt2Ag2(C6F5)4(CCPh)4] (X = F, Cl; R = Ph, tBu) complexes are obtained by reaction between (NBu4)2[Pt2(μ-X′)2(C6X5)4] (X′ = Cl, X = F; X′ = I, X = Cl) and [Ag(CCR)]n (Pt:Ag ratio 1:2). Similar heterometallic derivatives Q2[Pt2M2(C6F5)4 (CCR)4] (Q = PMePh3, NBu4; M = Ag, Cu; R = Ph, tBu) can be prepared by reaction of Q2[cis-Pt(C6F5)2(CCR)2] with AgCl or CuCl (Pt:M ratio 1:1). The structure of (NBu4)2[Pt2Ag2(C6F5)4 (CCPh)4]·4CH2Cl2 has been determined by X-ray diffraction.

Polynuclear platinum–silver, –copper, and –gold acetylide complexes. Molecular structure of [Pt2Ag4(CCBut)8]

Hexanuclear complexes [Pt2Ag4(CCR)8] [R = Ph (1) or But (2)] have been obtained by treating [PtCl2(tht)2] (tht = tetrahydrothiophene) with [Ag(CCR)]n(Pt/Ag 1 : 4). The complexes [Pt2M4(CCR)8] [M = Cu, R = Ph (3) or But (4); M = Au, R = But (5)] were obtained from [Pt2Ag4(CCR)8] with CuCl or [AuCl(tht)] respectively. Alternatively, the reactions between [NBu4]2[Pt(CCR)4] and AgClO4, CuCl–NaClO4, or [AuCl(tht)]–NaClO4 yield respectively complexes (1)–(5). The molecular structure of [Pt2Ag4(CCBut)8] has been determined by an X-ray diffraction study: monoclinic, space group C2 with a = 37.062(7), b = 12.0223(16), c = 20.459(3) A, β = 107.485(15)°, Z = 6, R 0.0416, R′ 0.0465 for 5 613 reflections with F > 6σ(F). The six metal atoms are arranged in a slightly irregular octahedron with the platinum atoms mutually trans and the silver atoms in the equatorial plane, with Pt ⋯ Ag and Ag ⋯ Ag distances longer than 3.0 A. Each platinum atom is in an almost square-planar environment formed by four CCBut ligands. Each acetylenic fragment also forms an asymmetric π interaction with one silver atom of the equatorial positions so that each silver atom is bonded to two acetylenic fragments, of two different Pt(CCBut), moieties. These moieties of each [Pt2Ag4(CCBut)8] unit are staggered.

Luminescent one- and two-dimensional extended structures and a loosely associated dimer based on platinum(II)-thallium(I) backbones.

Neutralization reactions between (NBu4)2[ trans-Pt(C 6F5)2(CN)2] 1 and (NBu4)2[cis-Pt(C6F5)2(CN)2] 2 with TlPF 6 have been carried out, and the resulting structures of [trans,trans,trans-Tl2{Pt(C6F5)2(CN)2}.(CH3COCH3) ] n [4.(CH3COCH3)2] n and {Tl[Tl{cis-Pt(C6F5)2(CN)2}].(H2O)} n [5.(H2O)] n have been determined by X-ray crystallography. Remarkably, the change from trans to cis geometry on the platinum substrate causes a significant decrease in the Pt(II)...Tl(I) metallophilic interaction. Thus, the platinum center in the trans fragment easily connects with two Tl(I) ions forming a distorted pseudo-octahedron PtTl2, which generates a final two-dimensional layered structure by secondary additional intermolecular Tl(I)...N(CN) interactions. However, the [cis-Pt(C6F5)2(CN)2] (2-) fragment interacts strongly with just one Tl center leading to an extended helical [-Pt-Tl-Pt-Tl-] n(n-) chain. In this case, the second thallium center neutralizes the anionic chain mainly through Tl...N(CN) ( intra) and Tl...F(C 6F 5) (intra and inter)actions. The reaction of TlPF 6 with the monoanionic fragment (NBu4)[cis-Pt(C6F5)2(CN)(PPh2C[triple bond]CPh)] 3 yields the discrete associated dimer [Tl{cis-Pt(C6F5)2(CN)(PPh2C[triple bond]CPh)}] 2 [ 6] 2. Dimer [ 6] 2 could be described as two square pyramids with the thallium atoms in the apical positions, connected through Tl...N(cyano) interactions. The final heteropolynuclear Pt-Tl complexes, except 4 at room temperature, show bright emission in the solid state when irradiated with UV-vis radiation, in contrast to the precursors 1 and 3, which are not luminescent. This difference indicates that the emissions in 4- 6 are presumably related to the interaction between the metal centers. The Pt-Tl bonding interactions and, consequently, the emissive properties are lost in solution at room temperature, as shown by the conductivity and NMR measurements. However, variable-concentration luminescence measurements in glassy acetonitrile solutions indicate the formation of different aggregates with different degrees of Pt...Tl interactions for 4 and 5 and a dimeric structure similar to that observed in solid state for 6.

Solvent-induced lone pair activity tuning and vapoluminescence in a Pt2Pb cluster

We report a novel cluster, [{Pt(C6F5)(bzq)}2Pb(Spy)2] 1, that displays reversible vapoluminescence to specific organic vapours; this behaviour can be related to the stereochemical activity of the lone pair around the Pb(II) in the ground state and to the distinct distortion of the coordination environment (1 and 1-solvent) upon photoexcitation.

Synthesis and characterization of mono and heteropolynuclear luminescent alkynyl platinum diphenylphosphinous acid/phosphinite complexes

Abstract The novel anionic mononuclear cis -bis(alkynyl) platinum complexes with a chelated diphenylphosphinous acid/diphenylphosphinite (NBu 4 )[ cis -Pt(CCR) 2 {(PPh 2 O) 2 H}] (R=Bu t 1a , Ph 1b ) have been prepared by treatment of [ cis -Pt(CCR) 2 COD] with PPh 2 (O)H and (NBu 4 )(acac) in a 1:2:1 molar ratio. The molecular structure of 1a has been determined by single-crystal X-ray diffraction. Neutralization reactions of complexes 1 with 1 equiv. of AgClO 4 or CuTfO (TfO=triflate) produce tetranuclear dimetallic complexes [ cis -Pt{(PPh 2 O) 2 H}(μ-κ C α :η 2 -CCR) 2 M] 2 (M=Ag, 2a , 2b ; M=Cu 3a , 3b ), in which each anionic fragment {Pt}(CCR) 2 − ({Pt}=Pt{(PPh 2 O) 2 H}) acts as a μ-η 2 :η 2 bridging ligand towards two different silver(I) or copper(I) centres. Finally, the reactions of (NBu 4 ){Pt}(CCR) 2 1 with [CuCl] n produce heterodinuclear platinum(II)–copper(I) complexes (NBu 4 )[ cis -Pt{(PPh 2 O) 2 H}(μ-κ C α :η 2 -CCR) 2 CuCl] ( 4a , 4b ), in which both alkyne units are η 2 -coordinated side-on to the copper(I) chloride. All complexes are emissive in frozen CH 2 Cl 2 solutions.

Double Insertion of Coordinated Phosphanylalkyne Ligands into a Pt−C6F5 Bond

Enhanced reactivity is shown by uncoordinated C identical withC bonds in the proximity of a metal in phosphanylacetylene complexes. cis-[Pt(C(6)F(5))(2)(thf)(2)] reacts with [M(C(6)F(5))(2)(PPh(2)C identical withCPh)(2)] (M=Pt, Pd) to form binuclear complexes containing the novel 2,3-bis(diphenylphosphanyl)-1,3-butadien-1-yl bridging ligand. Substitution of the solvent ligands with, for example, PPh(2)H (see picture) provides species that could be characterized by X-ray crystallography.

Synthesis and characterization of bis(η2-alkyne)dihalogeno-mercury(II) compounds: crystal structure of [NBu4]2-[{cis-Pt(C6F5)2(CCSiMe3)2}HgBr2]·CH2Cl2

The reactions of [NBu4]2[cis-Pt(C6F5)2(CCR)2](R = But or SiMe3) with HgX2(X = Cl, Br or I) in a 1:1 molar ratio afforded the simple monomeric bis(η2-alkyne)mercury(II) compounds [NBu4]2[{cis-Pt(C6F5)2(CCR)2}HgX2](R = But or SiMe3; X = Cl, Br or I) in which both alkyne units are co-ordinated η2 side-on to the precursor mercury(II) halides. Similar treatment of [NBu4]2[Pt(CCR)4]·2H2O (R = But or SiMe3) with HgX2 in a 1:2 molar ratio gave the corresponding trinuclear 1:2 adducts. All the complexes have been characterized by analytical and spectroscopic data and, in addition, the molecular structure of [NBu4]2[{cis-Pt(C6F5)2(CCSiMe3)2}HgBr2]·CH2Cl2 has been determined by X-ray diffraction methods. The structure of the anion shows that the HgBr2 unit is attached to the dianionic fragment [Pt(C6F5)2(CCSiMe3)2]2– only through η2 side-on co-ordination of the two (trimethylsilyl)ethynyl ligands. The platinum–mercury distance is 3.627(1.5)A.

Homo- and hetero-dinuclear complexes of palladium and platinum containing phosphinoacetylene and/or chloride as bridging ligands

Reactions between the diphenylacetylenephosphine complexes cis-[M′Cl2(PPh2CCR)2](M′= Pt or Pd, R = Ph or But) and cis-[M(C6F5)2(thf)2](M = Pt or Pd; thf = tetrahydrofuran) in a 1 : 1 molar ratio have been studied. Three types of products have been obtained: (a) asymmetric homo- and hetero-dinuclear complexes gem-[(C6F5)2M(µ-Cl)2M′(PPh2CCR)2], (b) symmetric trans-palladium derivatives [{Pd(µ-Cl)(C6F5)(PPh2CCR)}2] and (c) the unusual chloride and diphenyl (phenylethynyl) phosphine bridged dinuclear compounds [(C6F5)2Pt(µ-Cl)(µ-PPh2CCPh)M′Cl(PPh2CCPh)]. The complexes have been characterised by microanalysis, IR and NMR spectroscopy and the molecular structure of [(C6F5)2Pt(µ-Cl)(µ-PPh2CCPh)PtCl(PPh2CCPh)]·OC4H8. The NMR spectral data (1H, 19F and 31P) indicate that, in solution, mixtures of isomers [(C6F5)2Pt(µ-Cl)2M′(PPh2CCR)2] and [(C6F5)2Pt(µ-Cl)-(µ-PPh2CCPh)M′Cl(PPh2CCPh)] are present.

Dalton communications. Neutral PtAg2 clusters containing unsymmetrical µ3-σ and µ-η2,σ alkynyl groups. Crystal structure of [PtAg2(C6F5)2(µ-η2,σ-CCPh)(µ3-σ-CCPh)(PPh3)2]·0.25CH2Cl2

The reaction between [{PtAg2(C6F5)2(CCR)2}n] and triphenylphosphine in a molar ratio of 1 : 2 has resulted in a good yield of the trinuclear mixed-metal complexes [PtAg2(C6F5)2(µ-η2,σ-CCR)(µ3-σ-CCR)(PPh3)2](R = Ph 3 or But4), and the crystal structure of 3 revealed that they contain two different types of unsymmetrical µ3-σ and µ-η2, σ-edge-bridging alkynyl ligands.

Novel heterobimetallic titanium–platinum complexes. Crystal structure of [(η5-C5H4SiMe3)(SPh)Ti(μ,η5-κS-C5H4P(S)Ph2)(μ-SPh)Pt(C6F5)2]

Abstract The thiophosphorylcyclopentadienyl-thiolate complexes [(η5-C5H4R)(η5-C5H4P(S)Ph2)Ti(SPh)2] react with cis-[Pt(C6F5)2(THF)2] initially give the adducts [(η5-C5H4R)(SPh)Ti(μ,η5-κS-C5H4P(S)Ph2)(μ-SPh)Pt(C6F5)2] [R=P(S)Ph2 (1); SiMe3 (4)], which finally rearrange in solution to form the double thiolate-bridged derivatives [(η5-C5H4R)(η5-C5H4P(S)Ph2)Ti(μ-SPh)2Pt(C6F5)2] [R=P(S)Ph2 (2) (syn); SiMe3 (5) (syn/anti)]. This paper presents the crystal structure of 4, a complex displaying an unusual mixed thiolate-thiophosphorylcyclopentadienyl bridging system. In contrast, similar reactions of cis-[Pt(C6F5)2(THF)2] with [(η5-C5H4R)(η5-C5H4P(O)Ph2)Ti(SPh)2] (R=P(O)Ph2; SiMe3) only gives [(η5-C5H4R)(η5-C5H4P(O)Ph2)Ti(μ-SPh)2Pt(C6F5)2] [R=P(O)Ph2 (3) (syn); SiMe3 (6) (syn/anti mixtures)] as expected due to the soft acid nature of the platinum centre.