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

Alper, Fatma
Kayran, Ceyhan
Özkar, Saim
Pentacarbonylpyrazinetungsten(0), (CO)(5)W(pyz), is not stable in solution in polar solvents such as acetone or dichloromethane and undergoes conversion to a bimetallic complex, (CO)(5)W(pyz)W(CO)(5) plus free pyrazine. These three species exist at equilibrium. Using the quantitative H-1 NMR spectroscopy, the equilibrium constant could be determined to be K-eq = (5.9 +/- 0.8) x 10(-2) at 25 degrees 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 degrees C in tetrahydrofuran and characterized by elemental analysis, IR, MS, H-1, C-13 and P-31 NMR spectroscopy.


Coupling of pentacarbonyl[(cyclopropyl)methoxymethylene]molybdenum complex with ferrocenylalkynes: Synthesis of ferrocenyl-substituted cycloheptadienones and cycloheptenediones
Zora, Metin; Odabasoglu, Mustafa; Bueyuekguengoer, Orhan (2007-03-01)
Pentacarbonyl[(cyclopropyl)methoxymethylene ]molybdenum complex reacts with ferrocenyl alkynes to afford ferrocenyl-substituted 2,4-cycloheptadienones as major products, accompanied by varying amounts of 2-cycloheptene-1,4-diones and/or 2-cyclobutenones. 2-Cycloheptene-1,4-diones are secondary reaction products and result from initially formed 2,4-cycloheptadienones via hydrolysis. In one reaction, a hydroxy-substituted 2,4-cycloheptadienone derivative was isolated, which was not observed previously from si...
Effect of substituents in sulfoxides on the enhancement of thermoelectric properties of PEDOT:PSS: experimental and modelling evidence
Zhu, Qiang; Yıldırım, Erol; Wang, Xizu; Kyaw, Aung Ko Ko; Tang, Tao; Soo, Xiang Yun Debbie; Wong, Zicong Marvin; Wu, Gang; Yang, Shuo-Wang; Xu, Jianwei (2020-06-01)
Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), being the most popular conductive polymer, has been doped with various additives with the aim of improving its thermoelectric performance. Among all additives, dimethyl sulfoxide (DMSO) has been widely used for various treatments. In this work, we designed and synthesized a series of aliphatic- and aromatic-substituted sulfoxides as dopants to improve the thermoelectric properties of PEDOT:PSS. It was found that the substituents in the sul...
Özkar, Saim; KREITER, CG (1992-08-04)
1,2-Bis(dimethylphosphino)ethane-dicarbonyl-eta-4-diene-tungsten(0) complexes (diene = 1,3-butadiene (1), E-1,3-pentadiene (2), E,E-2,4-hexadiene (3) and E-2-methyl-1,3-pentadiene (4)) were synthesized by UV irradiation of 1,2-bis(dimethylphosphino)ethane-tetracarbonyltungsten(0) and the corresponding dienes in toluene. The constitutions of these complexes were determined by IR and NMR spectroscopy (H-1, C-13, P-31). The spectral data indicate pseudo-octahedral structures for the complexes. When the dienes ...
Insertion of Fischer Carbene Complexes into the Carbon-Carbon Bond of 1,2-Diphenylcyclopropenone: Formation of Cyclobutenones and o- and p-Methoxyphenol Derivatives
Zora, Metin (American Chemical Society (ACS), 1994-08-01)
Synthesis and characterizations of N,N-bis(diphenylphosphino)ethylaniline derivatives and X-ray crystal structure of palladium (II), platinum (II) complexes
DURAP, FEYYAZ; BİRİCİK, NERMİN; Guemguem, Bahattin; Özkar, Saim; Ang, Wee Han; Fei, Zhaofu; Scopelliti, Rosario (2008-01-20)
N,N-Bis(diphenylphosphino)ethylaniline compounds, [Ph2P](2)N-C6H4-C2H5, with ethyl groups at the ortho- and para-positions have been synthesized. Oxidation of the aminophosphines with hydrogen peroxide, elemental sulfur and selenium gave the corresponding oxides, sulfides and selenides [Ph2P(E)](2)N-C6H4-C2H5 (E = O, S, Se). Complexes [MCl2{(Ph2P)(2)N-C6H4-(C2H5)}] (M = Pd, Pt) and [Cu{(Ph2P)(2)N-C6H4-C2H5)(2)]PF6 were obtained by the reaction of NN-bis(diphenylphosphino)ethylaniline with [MCl2(COD)] (M = P...
Citation Formats
F. Alper, C. Kayran, and S. Özkar, “A stable carbonyl-pyrazine-metal(0) complex: Synthesis and characterization of cis-tetracarbonylpyrazinetrimethylphosphitetungsten(0),” JOURNAL OF ORGANOMETALLIC CHEMISTRY, pp. 2734–2738, 2006, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/33162.