RETARDATION EFFECT OF TRIMETHYL PHOSPHITE ON CHELATE RING-CLOSURE OF 2,2'-BIPYRIDINE (BIPY) IN CIS-[W(CO)4(P(OME)3)-(BIPY)]

Date

1994-08-07

Author

KAYRAN, C
Özkar, Saim
SULTAN, WIM

Metadata

Show full item record

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

Item Usage Stats

86
views

0
downloads

In order to study the effect of a donor ligand on the chelate ring-closure reaction of a diimine ligand co-ordinated in monodentate fashion, cis-[W(CO)4{P(OMe)3}(bipy)] was synthesised from [W(CO)5{P(OMe)5}] and 2,2'-bipyridine (bipy) by using a newly developed method and characterized by means of IR and NMR spectroscopies. The complex was found to undergo neither cis-->trans isomerization nor chelation thermally up to 150-degrees-C. However the ring-closure reaction occurs photochemically. Thus irradiation of the complex yielded fac-[W(CO)3{P(OMe)3}(bipy)] which was also isolated and characterized. The extraordinary retardation effect of trimethyl phosphite on the ring-closure reaction of the 2,2'-bipyridine ligand is attributed to the reduction in substitution lability of the CO groups in the complex upon introduction of the phosphite donor ligand.

Subject Keywords

Metal hexacarbonyl solutions, C-13 nmr-spectra, m = cr, Reaction-kinetics, Electronic absorption, Diimine ligands, W complexes, Photolysis, Photochemistry, Spectroscopy

URI

https://hdl.handle.net/11511/36128

Journal

JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS

DOI

https://doi.org/10.1039/dt9940002239

Collections

Department of Chemistry, Article

Suggestions

OpenMETU
Core

PENTACARBONYL(1,4-DIISOPROPYL-1,4-DIAZABUTADIENE)CHROMIUM - ISOLATION AND REACTIVITY OF THE MONODENTATE INTERMEDIATE EN-ROUTE TO CR(CO)4(IPROP-DAB) CHELATE RING-CLOSURE GREVELS, FW; KAYRAN, C; Özkar, Saim (1994-08-01) Exchange of the olefin ligand in Cr(CO)5(eta2-(Z)-cyclooctene) by 1,4-diisopropyl-1,4-diazabutadiene (iprop-DAB) yields Cr(CO)5(iprop-DAB) (1), where the potentially bidentate DAB ligand coordinates in a monodentate fashion. Complex 1 is isolated as red crystals and fully characterized (elemental analysis, IR, UV-vis, H-1 NMR and C-13 NMR spectra). In hydrocarbon solution at ambient temperature it decays via two competitive routes involving (a) chelate ring closure with CO extrusion to form Cr(CO)4(iprop-DA...
Synthesis and characterization of tetracarbonylpyrazinetrimethylphosphitetungsten (0) complexes Alper, Fatma; Özkar, Saim; Department of Chemistry (2004) In this study, the effect of a donor ligand on the stabilization of a carbonyl pyrazine tungsten complex was studied. The pentacarbonylpyrazinetungsten(0) complex could be formed from the photolysis of hexacarbonyltungsten(0) in the presence of pyrazine and could be isolated as crystalline solid. However, the complex was found to be unstable in solution, being converted to a bimetallic complex, (CO)5W(pyz)W(CO)5 and free pyrazine molecule. Two complexes exist in solution at equilibrium. The equilibrium cons...
The impact of [1,2,5]chalcogenazolo[3,4-f]-benzo[1,2,3]triazole structure on the optoelectronic properties of conjugated polymers Alkan, Ecem Aydan; GÖKER, SEZA; Sarigul, Hatice; Yıldırım, Erol; Udum, Yasemin Arslan; Toppare, Levent Kamil (2020-04-01) Two novel conjugated near-infrared (NIR) absorbing donor-acceptor type copolymers comprising benzodithiophene as the donor and [1,2,5]chalcogenazolo[3,4-f]-benzo[1,2,3]triazole derivatives as the acceptors, spaced with thiophene as the pi-bridge, were designed and synthesized via Stille polycondensation reaction. The effect of acceptor strength on optoelectronic properties was targeted and investigated. Branched alkyl chains (the extended 2-octyl-1-dodecyl alkyl chain; -C8C12) were introduced to 5H-[1,2,3]t...
Alkyl end group Modification of Benzotriazole and Thiophene Containing Conjugated Polymers Cevher, Şevki Can; Keleş, Duygu; Özdemir Hacıoğlu, Şerife; Toppare, Levent Kamil; Çırpan, Ali (null; 2016-07-21) This study focused on modifying the alkyl‐end‐group of benzotriazole and thiophene containing conjugated polymers. Introducing a moiety with struc‐turally rigid and tendency to enhance the π‐π stacking and also absorption in the high energetic region, influence the both electronic and optic properties of the conjugated polymers. Stille cross coupling chemical polymerization method was performed to synthesize the polymer contains: benzotriazole and bisthiophene. Characterizations of polymers were done in ter...
The expression of GST isoenzymes and p53 in non-small cell lung cancer. OguztĂźzun, Serpil; Aydin, Mehtap; Demirag, Funda; Yazici, UlkĂź; Ozhavzali, MĂźzeyyen; KiliĂ§, Murat; Can, Mesude IĹ (VM Media SP. zo.o VM Group SK, 2010-6-10) This study investigated the immunohistochemical staining characteristics of glutathione-S-transferase alpha, pi, mu, theta and p53 in non-small cell lung carcinoma and normal lung tissue from 50 patients. The relationships between expressions of the Glutathione-S-transferase isoenzymes and some clinicopathological features were also examined. Expression of glutathione-S-transferase pi, mu, alpha, theta and p53 was assessed by immunohistochemistry for primary lung carcinomas of 50 patients from the Sanitariu...

Citation Formats

C. KAYRAN, S. Özkar, and W. SULTAN, “RETARDATION EFFECT OF TRIMETHYL PHOSPHITE ON CHELATE RING-CLOSURE OF 2,2′-BIPYRIDINE (BIPY) IN CIS-[W(CO)4(P(OME)3)-(BIPY)],” JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS, pp. 2239–2239, 1994, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/36128.