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

Date

2006-06-01

Author

Alper, Fatma
Kayran, Ceyhan
Özkar, Saim

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

165
views

0
downloads

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.

Subject Keywords

Pyrazine, Carbonyl, Tungsten, Trimethylphosphite, Synthesis, Bimetallic complex, Equilibrium constant

URI

https://hdl.handle.net/11511/33162

Journal

JOURNAL OF ORGANOMETALLIC CHEMISTRY

DOI

https://doi.org/10.1016/j.jorganchem.2006.02.005

Collections

Department of Chemistry, Article

Suggestions

OpenMETU
Core

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...
13C- and 31P-NMR study of tetracarbonylbis(diphenylphosphino)alkanemetal(0) complexes of the group 6 elements Özer, Zahide; Özkar, Saim (1999-12-01) Tetracarbonylbis(diphenylphosphino)alkanemetal(0) complexes of the general formula M(CO)4[(C6 H5)2P (CH2)n P(C6H5)2] (M: Cr, Mo, W; n: 1, 2, 3) were synthesized from the reaction of M(CO)4(η2:2 -1,5-cyclooctadiene) with the appropriate ligand and characterized by means of IR and NMR (13 C and 31P) spectroscopy. Spectroscopic data shows that two phosphorus atoms in the complexes are identical and occupy two cis-coordiantion sites in a pseudo-octahedral coordination sphere of the metal. The comparative study ...
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...
HINDERED LIGAND MOVEMENTS IN TRANSITION-METAL COMPLEXES DECARBONYL (ETA-4-DIENE) TUNGSTEN(0) 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) Thereactionbetween1,2-diphenylcyclopro-penoneandFischercarbenecomplexeshasbeeninves-tigated.Thereactionproducedamixtureofdipheny-lacetyleneandcyclobutenones.Whena,ß-unsaturatedcarbenecomplexeswereemployed,benzannulationprod-uctsanddiphenylacetylenewereproduced.Amecha-nisminvolvingmetallacyclobutenoneformation,followedbyeithercarbeneinsertionandreductiveeliminationorfragmentationhasbeenproposed.Recently,wereportedthatcarbon—carbonbondin-sertionisthemajorreactionpathwaywhenFischercarbenecomplexesreactwith1,2-...

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.