79244-47-6Relevant academic research and scientific papers
Measurement of Diphosphine σ-Donor and π-Acceptor Properties in d0 Titanium Complexes Using Ligand K-Edge XAS and TDDFT
Lee, Kyounghoon,Wei, Haochuan,Blake, Anastasia V.,Donahue, Courtney M.,Keith, Jason M.,Daly, Scott R.
, p. 10277 - 10286 (2018)
Diphosphines are highly versatile ancillary ligands in coordination chemistry and catalysis because their structures and donor-acceptor properties can vary widely depending on the substituents attached to phosphorus. Experimental and theoretical methods have been developed to quantify differences in phosphine and diphosphine ligand field strength, but experimentally measuring individual σ-donor and π-acceptor contributions to metal-phosphorus bonding remains a formidable challenge. Here we report P and Cl K-edge X-ray absorption spectroscopy (XAS), density functional theory (DFT), and time-dependent density functional theory (TDDFT) studies of a series of [Ph2P(CH2)nPPh2]TiCl4 complexes, where n = 1, 2, or 3. The d0 metal complexes (Ti4+) revealed both P 1s → Ti-P π and P 1s → Ti-P σ? transitions in the P K-edge XAS spectra, which allowed spectral changes associated with Ti-P σ-bonding and π-backbonding to be evaluated as a function of diphosphine alkane length. DFT and TDDFT calculations were used to assign and quantify changes in Ti-P σ-bonding and π-backbonding. The calculated results for [Ph2P(CH2)2PPh2]TiCl4 were subsequently compared to electronic structure calculations and simulated spectra for [R2P(CH2)2PR2]TiCl4, where R = cyclohexyl or CF3, to evaluate spectral changes as a function of diphosphine ligand field strength. Collectively, our results demonstrate how P K-edge XAS can be used to experimentally measure M-P π-backbonding with a d0 metal and corroborate earlier studies showing that relative changes in covalent M-P σ bonding do not depend solely on changes in diphosphine bite angle.
Single-source CVD routes to titanium phosphide
Blackman, Christopher S.,Carmalt, Claire J.,Parkin, Ivan P.,Apostolico, Leonardo,Molloy, Kieran C.,White, Andrew J. P.,Williams, David J.
, p. 2702 - 2709 (2007/10/03)
Treatment of TiCl4 with two equivalents of L (L = PhPH2, Ph2PH, PPh3, CyPH2, Cy2PH, PCy3) resulted in the formation of [TiCl4(L)2]. Reaction of TiCl4/
Synthesis, spectroscopic and structural studies on six- and eight-coordinate phosphane and arsane complexes of titanium(IV) halides
Hart, Richard,Levason, William,Patel, Bhavesh,Reid, Gillian
, p. 2927 - 2933 (2007/10/03)
The six-coordinate complexes [TiX4(L-L)] [X = Cl or Br; L-L = Ph2PCH2PPh2, Ph2P(CH2)2PPh2, Ph2P(CH2)3PPh2, o-C6H
Complexation and Exchange Reactions of some Dimethylamino-substituted Group 4 Compounds
Wade, Steven R.,Willey, Gerald R.
, p. 1264 - 1267 (2007/10/02)
Reactions of CH2(NMe2)2, (1), SiMe2(NMe2)2, (2), (cp=η-cyclopentadienyl), (3), and , (4), with covalent metal halides MCl4 (M=Ti,Zr,Si,Ge,or Sn) and MCl3 (M=Ti,V,or Cr) fall into two categories: (a) N-donor chelation leading to complex formation and (b) halide-NMe2 exchange.Compound (1) gives 1:1 complexes with MCl4 (M=Ti or Sn) and 2:1 complex with VCl3.Compound (2) provides 1:1 complexes with MCl4 (M=Ti,Zr,Hf, or Sn).The decomposition of TiCl4*SiMe2(NMe2)2 --> invariably occurs in both the solid state and solution.There is no reaction of (2) with metal(III) chlorides.With MCl4 (M=Si or Ge 'scrambling' reactions involving halide-NMe2 exchange occur and these have been monitored by 1H n.m.r. spectroscopy.Reactions of (3) and (4) with MCl4 (M=Si,Ge,Sn,Ti,Zr,or Hf) consistently feature halide-NMe2 exchange rather than adduct formation.All complexes have been characterised by analytical and spectroscopic (1H n.m.r. and i.r.) investigations.
