Diphosphine Platinum Research Articles

Heteropolymetallic [FeFe]-Hydrogenase Mimics: Synthesis and Electrochemical Properties.

The synthesis and electrochemical properties of tetranuclear [Fe2S2]-hydrogenase mimic species containing Pt(II), Ni(II), and Ru(II) complexes have been studied. To this end, a new tetranuclear [Fe2S2] complex containing a 5,5'-diisocyanide-2,2'-bipyridine bridging ligand has been designed and coordinated to the metal complexes through the bipyridine moiety. Thus, the tetranuclear [Fe2S2] complex (6) coordinates to Pt(II), Ni(II) and Ru(II) yielding the corresponding metal complexes. The new metal center in the bipyridine linker modulates the electronic communication between the redox-active [Fe2S2] units. Thus, electrochemical studies and DFT calculations have shown that the presence of metal complexes in the structure strongly affect the electronic communication between the [Fe2S2] centers. In the case of diphosphine platinum compounds 10, the structure of the phosphine ligand plays a crucial role to facilitate or to hinder the electronic communication between [Fe2S2] moieties. Compound 10a, bearing a dppe ligand, shows weak electronic communication (ΔE = 170 mV), whereas the interaction is much weaker in the Pt-dppp derivative 10b (ΔE = 80 mV) and virtually negligible in the Pt-dppf complex 10c. The electronic communication is facilitated by incorporation of a Ru-bis(bipyridine) complex, as observed in the BF4 salt 12 (ΔE = 210 mV) although the reduction of the [FeFe] centers occurs at more negative potentials. Overall, the experimental-computational procedure used in this work allows us to study the electronic interaction between the redox-active centers, which, in turn, can be modulated by a transition metal.

Reactivity of a gold(i)/platinum(0) frustrated Lewis pair with germanium and tin dihalides.

The reactivity of germanium and tin dichlorides with a transition metal-only frustrated Lewis pair based on Au(i) and Pt(0) compounds bearing bulky phosphine ligands is described in this work. We have examined both the reactivity of tetrylene dihalides towards the individual components of the metallic pair, as well as under metal/metal cooperative conditions. These studies allowed us to isolate several uncommon homo- and heterometallic structures. Computational methods have been employed to investigate the bonding scheme of one of these highly-reduced metallic aggregates. In addition, we have developed a tin-promoted strategy to access heteroleptic diphosphine platinum(0) compounds.

Room temperature reversible C–H activation mediated by a Pt(0) center, and stoichiometric biphenyl formation via solvent activation

Room temperature reversible C-H activation mediated by a designed diphosphine platinum complex is presented. These findings are demonstrated through mechanistic studies involving kinetics, isotopic effects, and corroborated by DFT calculations. The coupling between two unactivated aromatic derivatives is also demonstrated.

Preparation of Functional Hybrid Glass Material from Platinum (II) Complexes for Broadband Nonlinear Absorption of Light

AbstractThe synthesis of trans‐di(arylalkynyl)diphosphine platinum(II) complexes bearing trialkoxysilane groups is described, as well as the preparation of siloxane‐based hybrid materials from organometallic chromophores through a modified sol–gel process. Glass materials prepared from trans‐[P(n–Bu)3]2Pt[(C≡C–p–C6H4–C≡C–p–C6H4–CH2O(CO)NH(CH2)3Si(OC2H5)3]2 generally show spectral transmittance, absorption and luminescence similar to that of solutions reported in the literature. Measurements of optical power limiting for the hybrid glass are carried out, and show broadband nonlinear absorption throughout the whole visible wavelength range with clamping values in the range 0.2–7 µJ at 120 mM chromophore concentration. The sol–gel process using urethane‐propyltriethoxysilane‐functionalized chromophores as precursors appears to be a valid method for formation of robust silicate materials with grafted diarylethynyl Pt(II) complexes for OPL devices.

Synthesis and Characterization of Chiral Diphosphine Platinum(II) VANOL and VAPOL Complexes

Synthesis and Characterization of Chiral Diphosphine Platinum(II) VANOL and VAPOL Complexes

Synthesis and Characterization of Chiral Diphosphine Platinum(II) VANOL and VAPOL Complexes

Reaction of (dppe)PtCO3 with S-VANOL or S-VAPOL yielded (dppe)Pt(S-VANOL) and (dppe)Pt(S-VAPOL), respectively. NMR data indicate that the VANOL ligand in the former complex adopts a C2-symmetric O,O‘-bound form, while the VAPOL ligand binds to the metal in a C,O-binding mode that partially disrupts the ligand aromaticity. When matched complexes of S-VANOL and S-VAPOL were synthesized with (S,S-chiraphos)PtCO3, both complexes adopt the symmetric O,O‘-mode. Mismatched complexes with (R,R-chiraphos)PtCO3 have both ligands adopting the C,O-binding mode; however, the S-VANOL complex could not be isolated. Competition experiments between S-VANOL and S-VAPOL for the (S,S-chiraphos)Pt2+ fragment indicate that VANOL is the thermodynamically preferred ligand.

Chiral effects on a fluxional ligand: chiral diphosphine platinum(ii) complexes with thiacrowns

We report the syntheses, crystal structures, and spectroscopic properties for two new Pt(II) heteroleptic complexes containing the chiral diphosphine ligands R-BINAP and R,R-Chiraphos along with crown trithioether [9]aneS3 (1,4,7-trithiacyclononane). The complexes have the general formula [Pt([9]aneS3)(P2)](PF6)2 (P2 = R-BINAP or R,R-Chiraphos) and form similar structures in which the Pt(II) center is surrounded by a cis arrangement of the two P donors from the diphosphine chelate and two sulfur atoms from the trithioether macrocycle. The third sulfur in each complex shows a long distance interaction with the metal, resulting in an elongated square pyramidal structure with platinum–axial sulfur distances ranging from 2.695(3) to 2.802(2) A with the Chiraphos complex showing the shorter distance. The X-ray crystal structure of the Chiraphos complex exhibits an unusual example of co-crystallization of solid state conformational diastereoisomers within the same unit cell. The unit cell consists of two crystallographically independent complex cations which are related by a conformational change around one carbon–carbon bond in the [9]aneS3 ligand. The 195Pt NMR chemical shifts for both complexes fall in the range of −4167 to −4452 ppm, consistent with a cis-PtS2P2 coordination sphere. The effects of chirality of the diphosphine are most notably seen in the 13C NMR spectrum of the fluxional [9]aneS3 ligand, resulting in two separate resonances as opposed to the single one which has always been observed in Pt complexes containing achiral diphosphines.

Comparative time-resolved IR and UV spectroscopic study of monophosphine and diphosphine platinum(II) azido complexes

Solution of cis-diazido-bis(triphenylphosphine)platinum(II) cis-[Pt 11(PPh 3) 2(N 3) 2] and diazido-1,3-(diphenylphosphino)-propaneplatinum(II) ([Pt 11(dppp)(N 3) 2] were studies by time-resolved IR and UV-Vis absorption spectroscopy after excitation by 308 nm laser pulses. Photoinduced electron transfer reduces [Pt 11(dppp)(N 3) 2] to [Pt 1(dppp)N 3] (IR maximum 2045 cm −1) which decays in several solvents at room temperature (half-life ∼ 0.3 ms) via intramolecular electron transfer to coordinatively unsaturated [Pt 0(dppp)]. With cis-[Pt II(PPh 3) 2(N 3) 2]. photoisomerization to rans-[Pt II(PPh 3) 2(N 3) 2] (IR maximum 2050 cm −) and photoreduction compete as primary photoreactions, whereas the decay of [Pt I(PPh 3) 2N 3] is analogous to that of [Pt I(PPh 3) 2(N 3) 2]. Oxygen scavenges [Pt I(PPh 3) 2N 3] and [Pt I(dppp)N 3] with rate constant k 0=(1.3–2.8) × 10 7M −1. The photochemistry of cis-[Pt II(PPh 3) 2] and [Pt II(dppp)(N 3) 2] in the absence adn presence of O 2 is dicussed.

Novel diphosphine platinum cations: NMR and Mössbauer spectra and catalytic studies

The reaction of PtCl 2(diphosphine) with mono and bidentate phosphines has been investigated by NMR spectroscopy. [Pt(diphosphine) (PMe 3) 2] 2+, [Pt(diphosphine) 2] 2+ and [Pt(( S, S)-bdpp)(( S, S)-chiraphos)] 2+ cations have been characterized by 31P NMR and conductivity measurements. The presence of tin(II) chloride promotes the formation of the complex cations. Evidence for coordination of the diphosphine in monodentate mode has benn obtained by NMR spectroscopy. The platinum species possessing a platinum-tin bond and ionic complexes with an SnCl 3 − counterion can easily be distinguished by 119Sn Mössbauer spectroscopy. Asymmetric hydroformylation of styrene with [Pt(( S, S)-bdpp) 2] 2+(SnCl 3 −) 2 as catalyst precursor gave chemo-, regio- and enantio-selectivities different from those obtained with the covalent PtCl(SnCl 3)(( S, S)-bdpp) as catalyst precursor.

Diphosphine platinum(II) photo-oxidants. Synthesis and photochemistry of luminescent diphosphine platinum(II) complexes of 5,6-dimethyl-1,10-phenanthroline

The [Pt(P–P)(5,6-Me2phen)]2+ complexes (P–P = chelating diphosphine, 5,6-Me2phen = 5,6-dimethyl-1,10-phenanthroline) exhibit photoluminescence at 490–495 nm: the excited state lifetimes and excited oxidation potentials are 22–25 µs and ∼2.1 V vs. normal hydrogen electrode (NHE), respectively.

ChemInform Abstract: Structure, Synthesis, and Characterization of Chiral Secondary Diphosphine Platinum(II) Mono‐ and Dimeric Complexes: Molecular Structure of (Pt2Cl4(SMe2)2((R*,R*)‐μ‐HtBuPCH2PtBuH)).

AbstractReaction of the Pt(II) complex (I) in greater than a 2‐fold excess with a 1:1 mixture of the diphosphines (IVa) and (IVb) leads to the isolation of the two new complexes (II) and (III) (no yields given).

Structure, synthesis, and characterization of chiral secondary diphosphine platinum(II) mono- and dimeric complexes: molecular structure of [Pt2Cl4(SMe2)2{(R*,R*)-.mu.-HtBuPCH2PtBuH}

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure, synthesis, and characterization of chiral secondary diphosphine platinum(II) mono- and dimeric complexes: molecular structure of [Pt2Cl4(SMe2)2{(R*,R*)-.mu.-HtBuPCH2PtBuH}]John C. Huffman and Brian R. LloydCite this: Inorg. Chem. 1989, 28, 16, 3087–3089Publication Date (Print):August 1, 1989Publication History Published online1 May 2002Published inissue 1 August 1989https://doi.org/10.1021/ic00315a001RIGHTS & PERMISSIONSArticle Views32Altmetric-Citations6LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (837 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Structure, synthesis and characterization of chiral, phosphido-phosphine, diphosphine platinum(II) mono- and dimeric complexes: The molecular structure of both [PT 2Cl 3{(R *)-μ- iPrPCH 2P iPr 2}{(R *)-H iPrPCH 2P iPr 2}] and [PT 2Cl 3{(R *)-μ- iPrPCH 2P iPR 2}{(S *,S *)-μ-H iPrPCH 2P iPrH}

The preparation and spectroscopic characterization of the chiral phosphidophosphine, diphosphine dimeric complex [Pt 2Cl 3{(R *)-μ- i PrPCH 2P i Pr 2}{(R *)-μ-H i PrPCH 2P i Pr 2}] ( 3a) is reported. The further isolation of [PtCl 2(H i PrPCH 2P i Pr 2)] ( 1) and [Pt 2Cl 3{(R *)-μ- i PrPCH 2P i Pr 2}{(R *)-H i PrPCH 2P i Pr 2}] ( 2b) has led to a rationalization of the racemate's, 3a, predomination, over other potential isomers, e.g. [Pt 2Cl 3{(R *)-μ- i PrPCH 2P i Pr 2}{(S *)-μ-H i PrPCH 2P i Pr 2}] ( 3b), in terms of its mechanism of formation. The mixed ligand dimer, [Pt 2Cl 3{(R *)-μ- i PrPCH 2P i Pr 2}{(S *,S *)-μ-H i PrPCH 2P i PrH}] ( 4), has also been prepared and characterized spectroscopically. The structures of 2b and 4 have been elucidated via X-ray diffraction studies.

ChemInform Abstract: The Preparation and Structure of the Bis‐vinyl Ether Complex Pt(Ph2PCH2CH2PPh2)((MeO2C)C=C(OMe)(CO2Me))2.

AbstractStarting with the complex (I) the diphosphine platinum dication is formed by chloride abstraction.

Co-ordinatively unsaturated diphosphine platinum(II) alkyl cations: a new class of β-agostic complexes

Treatment of tris(norbornene)platinum with diphosphines and subsequent protonation affords a series of cationic complexes [Pt(C7H11)(L2)]+(L2= peralkyldiphosphine) in which the norbornyl ligand binds to platinum viaσ-alkyl and β-C–H agostic interactions; the strength of the latter bond varies and has been characterised by n.m.r. and X-ray structure analysis.

THE EFFECT OF SUBSTITUENTS ON THE STABILITIES OF COMPLEXES OF PLATINUM WITH ARYL ACETYLENES AND PHOSPHINES

Compounds of platinum (0) with aryl phosphines are stabilized by electron-withdrawing substituants. A maximum coordination number of three is observed in such cases, suggesting that platinum tetracarbonyl cannot be prepared. Compounds in which one phosphine is replaced by an aryl acetylene are also stabilized by electron withdrawal by the acetylene and quantitative data are given on the relative stabilities of these compounds. These data indicate that a two-coordinated diphosphine platinum (0) compound might be stable if an appropriate substituted phosphine is used. The effect of substituents on the stabilities of these compounds is discussed.