Improved synthesis of the heteronuclear phosphido Mo–W complex and its use as MOCVD precursor

Basato, Marino; Brescacin, Enrico; Tondello, Eugenio; Valle, Giovanni

doi:10.1016/s0020-1693(01)00603-x

Cited by 12 publications

(10 citation statements)

References 14 publications

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“…19 Nevertheless, PP bond formation from the oxidation of two bridging phosphanido ligands, as far as we know, has never been observed. However, the reverse process—the reaction of P 2 R 4 with transition‐metal complexes—is an easy entry into phosphanido complexes of transition metals 20–23…”

Section: Methodsmentioning

confidence: 99%

Reversible Transformation of Two Diphenylphosphanido Ligands into the Neutral Tetraphenyldiphosphane Ligand

et al. 2005

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[1] , which contains a total of 46 valence electrons and hence a Pt À Pt bond. To our surprise, when the starting compound comprises at least one palladium center the analogous Pd III -containing derivatives cannot be isolated from, or identified in, the reaction mixtures. [1] To understand the different response of the heteronuclear species towards oxidation by Ag + ions, and guide our experimental efforts towards identifying and finally isolating the reaction products, we searched the potential energy surface (PES) of a model reaction system with electronic structure calculation methods at the B3LYP level of theory [2,3] using the LANL2DZ basis set, as implemented in the Gaussian 03 series of programs.[4] To obtain a computationally convenient size we used a model reaction system where the phenyl groups of the phosphanide ligands are substituted by H atoms and the C 6 F 5 ligands by CN ligands. The decision to substitute the C 6 F 5 ligands by CN is based on electronic structure calculations of the coordinating ability (s-donor and p-acceptor capacity) of the ligands and has been described previously.[5] The geometric and energetic profile of the oxidation reaction of M1 b, along with the HOMO of all stationary points, computed at the B3LYP/LANL2DZ level of theory is depicted schematically in Figure 1.One-electron oxidation of complex M1 b yields the intermediate open-shell (doublet) anionic species M1 b1, which is a symmetric (D 2h point group), trinuclear PtPdPt complex without any intermetallic interaction. This oneelectron oxidation step requires about 49.3 kcal mol À1 at the B3LYP/LANL2DZ level, which is provided by the reduction of the Ag + ions used as the oxidant (the electron affinity of the Ag + ions was predicted to be 178.7 kcal mol À1 ). Interestingly, the one-electron oxidation involves a strong coordination of the Ag + ion to Pd and one terminal Pt atom to afford complex M1 bAg, which adopts a chairlike structure (see Supporting Information) with a binding energy predicted to be 171.9 kcal mol À1 , thus illustrating that the Pd···Ag + and Pt···Ag + intermetallic bonds are relatively strong. These strong intermetallic interactions are also mirrored in the short Pd···Ag + and Pt···Ag + bond distances of 2.756 and 2.746 , respectively. Phosphanido Pt/Pd/Ag complexes of this type have recently been isolated by us.[6] It should be noted that the transfer of one electron is a favorable process because the LUMO of M1 bAg is localized purely on the coordinated Ag + ion. The salient feature of the structure of M1 b1 is the remarkable shortening of the P···P distance by about 0.29 with respect to the starting M1 b species. The localization of the spin density on the P atoms of the bridging phosphanido ligands (Figure 1) is also noteworthy as it indicates that P···P interactions should start to evolve during the course of the oxidation process. Further one-electron oxidation of M1 b1 leads to a second-order saddle point (probably an effective monkey-saddle-type transition state [7] possessing a doubly dege...

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Section: Methodsmentioning

confidence: 99%

Reversible Transformation of Two Diphenylphosphanido Ligands into the Neutral Tetraphenyldiphosphane Ligand

et al. 2005

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“…2 Furthermore, we have reported the synthesis of the binuclear complex [(CO) 4 W(μ-PHR)] 2 containing bridging PHR ligands (R = H 2 BNMe 3 ), which was obtained by the photolysis of the Lewis acid/base stabilized phosphanylborane complex [(CO) 5 W·PH 2 BH 2 ·NMe 3 ] (eq 1). 3 In addition to these neutral complexes, some anionic derivatives have been reported, for example, [{(CO) 4 9,10 Besides these homonuclear compounds, mixed bimetallic complexes of the type [(CO) 4 M(μ-EMe 2 ) 2 Fe(CO) 3 ] (M = Cr, Mo, W; E = P, As) 11 and [(CO) 4 M(μ-PMe 2 ) 2 M′(CO) 4 ] (M = Mo; M′ = W) 12 are also known. Using the latter compound as a single source precursor in a MOCVD (metal-organic chemical vapor deposition) process, Basato et al have deposited films with the stoichiometry predetermined by the precursor (Mo:W = 1:1).…”

Section: ■ Introductionmentioning

confidence: 99%

“…Using the latter compound as a single source precursor in a MOCVD (metal-organic chemical vapor deposition) process, Basato et al have deposited films with the stoichiometry predetermined by the precursor (Mo:W = 1:1). 12 However, they have not succeeded in avoiding the contamination of carbon in the films. Generally, the use of such single source precursors in the synthesis of transition-metal phosphide nanoparticles or films can yield highly selective compositions, but the appearance of carbon is also often a problem in these syntheses.…”

Section: ■ Introductionmentioning

confidence: 99%

Transition-Metal Complexes Containing Parent Phosphine or Phosphinyl Ligands and Their Use as Precursors for Phosphide Nanoparticles

et al. 2014

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P-H functional transition-metal complexes were synthesized without using hazardous PH3 gas in good yields by photolysis of the transition-metal carbonyl complexes M(CO)(6-x) (M = Cr, W, Fe; x = 0, 1) in tetrahydrofuran followed by reaction with P2(SiMe3)4 and subsequent methanolysis to give the bridging complexes [(CO)(x)M(μ-PH2)]2 (M = Fe, x = 3 (1), M = Cr, x = 4 (2a), M = W, x = 4 (2b)). The photolysis of [(CO)4M(μ-PH2)]2 (M = Cr (2a), M = W (2b)) with P(SiMe3)3 was applied followed by methanolysis to synthesize the PH2 bridging transition-metal binuclear complexes with terminal PH3 groups. The products [(CO)4M(μ-PH2)2M(CO)3(PH3)] (M = Cr (3a), M = W (3b)) and [(CO)4W(μ-PH2)2W(CO)2(PH3)2] (4b) were isolated in moderate yield. Another synthetic approach to this type of compounds is the direct photolysis of the complexes [(CO)3M(PH3)3] (M = Cr (5a), M = W (5b)). The products were comprehensively characterized by (31)P NMR and IR spectroscopy as well as by X-ray structural analysis. Additionally, the relevancy of 2a as single source precursor for the synthesis of stoichiometry-controlled CrP nanoparticles has been demonstrated.

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“…Also isolated and structurally characterised were the homonuclear dimers [M(µ-PMe 2 )(CO) 3 (PMe 3 )] 2 (M = Mo, W). 110 Reduction of [(η 6 -C 6 H 6 )Cr(CO) 3 ] led to the intermediate species K[(η 5 -C 6 H 7 )-Cr(CO) 3 ] which was then substituted by PPh 3 to give trans-[Cr(CO) 4 (PPh 3 ) 2 ] for which the crystal structure shows two conformational isomers that differ mainly in the orientation of the PPh 3 ligands. 111 An alternative synthesis has been reported for [(η 6 -C 6 H 5 Cl)Cr(CO) 2 PPh 3 ].…”

Section: Phosphorus- Arsenic- and Antimony-donor Ligandsmentioning

confidence: 99%

12 Chromium, molybdenum and tungsten

Malito¹

2002

Annu. Rep. Prog. Chem., Sect. A: Inorg. Chem.

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Improved synthesis of the heteronuclear phosphido Mo–W complex and its use as MOCVD precursor

Cited by 12 publications

References 14 publications

Reversible Transformation of Two Diphenylphosphanido Ligands into the Neutral Tetraphenyldiphosphane Ligand

Reversible Transformation of Two Diphenylphosphanido Ligands into the Neutral Tetraphenyldiphosphane Ligand

Transition-Metal Complexes Containing Parent Phosphine or Phosphinyl Ligands and Their Use as Precursors for Phosphide Nanoparticles

12 Chromium, molybdenum and tungsten

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