A stable carbonyl-pyrazine-metal(0) complex: Synthesis and characterization of cis-tetracarbonylpyrazinetrimethylphosphitetungsten(0)

Pentacarbonylpyrazinetungsten(0), (CO)₅W(pyz), is not stable in solution in polar solvents such as acetone or dichloromethane and undergoes conversion to a bimetallic complex, (CO)₅W(pyz)W(CO)₅ plus free pyrazine. These three species exist at equilibrium. Using the quantitative ¹H NMR spectroscopy, the equilibrium constant could be determined to be K_eq = (5.9 ± 0.8) × 10⁻² at 25 °C. Introducing a second pyrazine ligand into the molecule does not stabilize the complex, as cis-W(CO)₄(pyz)₂ was found to be less stable than W(CO)₅(pyz) and, therefore, could not be isolated. However, introducing trimethylphosphite as a donor ligand into the complex leads to the stabilization of the carbonyl-pyrazine-metal(0) complexes, as shown by the synthesis of cis-W(CO)₄[P(OCH₃)₃](pyz). This complex could be isolated from the reaction of the photogenerated W(CO)₄[P(OCH₃)₃](tetrahydrofuran) with trimethylphosphite upon mixing for 2 h at 10 °C in tetrahydrofuran and characterized by elemental analysis, IR, MS, ¹H, ¹³C, and ³¹P NMR spectroscopy.     

Synthesis,Crystal Structure and Electrochemical Behavior of a Fe(II) Complex of 8-Mercaptoquinoline (Hmtq) with Trimethylphosphite Participation

The mononuclear complex Fe(II)(mtq)₂{P(OCH₃)₃}₂ (Hmtq = 8-Mercaptoquinoline) with mixed N-heterocyclic thiolato and phosphite ligands was synthesized and characterized by X-ray crystallography and cyclic voltammetric measurement. The title complex crystallizes in the triclinic space group P-1 with a = 8.929(4), b = 9.965(3), c = 16.913(11) Å, α = 76.21(10), β = 80.89(10), γ= 68.010(10)°, V = 1351.2(11) ų. The Fe(II) atom exhibits an elongated octahedral geometry composed of N₂S₂P₂ donors. The equatorial plane is made up of two cis-oriented N donors from the thiolato ligands and two cis-oriented monodentate P(OCH₃)₃ ligands. The apical sites are occupied by two trans-oriented S atoms from the mtq^? ligands. The thione form is predominant coordination mode of 8-mercaptoquinoline with the N and S donors bound to the Fe(II) to form five-membered chelate rings. The structural feature of the mononuclear Fe(II) complex with mixed phosphite and thiolate ligands is summarized.     

Syntheses, X-ray structures and CVD studies of trimethylphosphite stabilized silver(I) methanesulfonates

The preparation of {[(MeO)₃P]_n·AgO₃SCH₃} (n = 1, 2a; n = 2, 2b) is described. The molecular structure of 2a was determined by using X-ray single crystal analysis. Complex 2a contains an Ag₄ rectangular make-up, the centroid of which constitutes an inversion center. Complex 2b was used as precursor in the deposition of silver films using metal organic chemical vapor deposition (MOCVD) technique for the first time. The silver films obtained were characterized using scanning electron microscopy (SEM) and energy-dispersion X-ray (EDX) analysis.     

亚磷酸三甲酯作为锂离子电池电解液溶剂的研究

为了提高锂离子电池电解液的热稳定性,使用亚磷酸三甲酯TMP作为溶剂来配置锂离子电池电解液,研究该电解液燃烧性能、电化学性能和热稳定性,并与商业用电解液作了比较.循环性能测试结果表明,亚磷酸三甲酯基电解液与正极材料LiNg0.8Co0.2O2有很好的相容性,有良好的电化学稳定性,而且与PC组成电解液时可一定程度地抑制PC对负极石墨材料的剥离.燃烧试验和微量量热实验表明,TMP的加入能显著地提高电解液的热稳定性与安全性能.     

Trimethylphosphite stabilized disilver(I) methanedisulfonates as MOCVD precursors

New disilver(I) methanedisulfonates complexes {CH₂(SO₃)₂Ag₂·[P(OMe)₃]_n} (n = 2, 2a; n = 4, 2b; n = 6, 2c) were prepared by reacting [CH₂(SO₃)₂Ag₂], which could be synthesized from methanedisulfonic acid and Ag₂CO₃ in water, with trimethylphosphite in dichloromethane. The molecular structure of 2a was determined using X-ray single crystal analysis. Complex 2a exhibits an infinite chain structure with eight-membered rings (AgOSOAgOSO) fully interconnected by the third sulfonic O atoms. Complex 2b was used to deposit silver films by metal organic chemical vapor deposition (MOCVD) for the first time. The silver film obtained was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersion X-ray analysis (EDX).     

Carbonyltungsten(0) complexes of acryloylferrocene: Synthesis and characterization

Photolysis of hexacarbonyltungsten(0) in the presence of acryloylferrocene in n-hexane solution at 10 °C yields pentacarbonyl(η²-acryloylferrocene)tungsten(0) (1) as the only photo-substitution product, different from the general reaction pattern observed for the Group 6 metal carbonyls with other olefins. W(CO)₅(η²-acryloylferrocene) (1) decomposes in solution to the parent hexacarbonyltungsten(0) and free acryloylferrocene. Trimethylphosphite was introduced as ligand into the molecule to increase the stability. The photolysis of pentacarbonyl(trimethylphosphite)tungsten(0) in the presence of acryloylferrocene in n-hexane solution at 10 °C yields only cis-W(CO)₄[P(OCH₃)₃](η²-acryloylferrocene) (2) as the monosubstitution product. Both η²-acryloylferrocene complexes (1 and 2) could be isolated and characterized by MS, IR and NMR spectroscopy. The trimethylphosphite complex (2) is found to be even less stable than W(CO)₅(η²-acryloylferrocene) (1).     

1,1,3,3,3-Pentafluoro-2-pentafluorophenyl-1,2-epoxypropane and trimethylphosphite: unusual 1,4-dioxan-2,5-dione ring formation

1,1,3,3,3-Pentafluoro-2-pentafluorophenyl-1,2-epoxypropane 1 reacted with trimethylphosphite giving two diastereomers, (Z)- and (E)-3,6-bis(trifluoromethyl)-3,6-bis(pentafluorophenyl)-1,4-dioxan-2,5-dione 2a, b in a 1:1 ratio, cyclodimerisation product of the intermediately generated α-lactone 4. Compounds 2a, b were hydrolysed to furnish 3,3,3-trifluoro-2-hydroxy-2-(2,3,4,5,6-pentafluorophenyl)propionic acid 5.