HINDERED LIGAND MOTIONS IN TRANSITION-METAL COMPLEXES .18. SYNTHESIS AND DYNAMIC BEHAVIOR OF TRICARBONYL(ETA-DIENE)(TRIMETHYLPHOSPHANE)CHROMIUM(0) AND TRICARBONYL(ETA-DIENE)(TRIMETHYL PHOSPHITE)CHROMIUM(0)

Date

1983-01-01

Author

KOTZIAN, M
KREITER, CG
MICHAEL, G
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

114
views

0
downloads

Irradiation of Cr(CO)5[P(CH3)3] or Cr(CO)5[P(OCH3)3] in presence of 1,3‐butadiene (1), trans‐1,3‐pentadiene (2), and 2‐ethyl‐1,3‐butadiene (3), trans, trans‐2,4‐hexadiene (4), 2‐methyl‐1,3‐pentadiene (5), and 2‐ethyl‐1,3‐butadiene (6) produces in good yields Cr(CO)3L(η4‐diene) complexes (LP(CH3)3 1A–6A; LP(OCH3)3 1B–6B). The configurations of these complexes were determined by IR and NMR spectroscopy (1H, 13C, 31P). Cr(CO)3[P(OCH3)3](η4‐1,3‐pentadiene) (2B) and Cr(CO)3[P(OCH3)3](η4‐2,4‐hexadiene) (4B) form a mixture of two possible facial stereoisomers a and f. The other complexes favour only the a‐form. 2B and 4B show two different, intramolecular hindered ligand movements: Isomerization of the a‐ and f‐forms and carbonyl scrambling. Carbonyl scrambling is also observed for all the other complexes. The barriers of activation of these movements are around 40 and 50 kJ. mol−1, respectively. Transition states of trigonal prismatic geometries are suitable models to explain these movements.

Subject Keywords

Inorganic Chemistry

URI

https://hdl.handle.net/11511/69982

Journal

CHEMISCHE BERICHTE-RECUEIL

DOI

https://doi.org/10.1002/cber.19831161113

Collections

Department of Chemistry, Article

Suggestions

OpenMETU
Core

HINDERED LIGANDS IN TRANSITION-METAL COMPLEXES .39. SYNTHESIS AND DYNAMIC BEHAVIOR OF TETRACARBONYL-ETA-4-TRICYCLO[6.3.0.0(2.7)]UNDECA-3,5-DIENE METAL(0) COMPLEXES AND DICARBONYL-BIS-(ETA-4-TRICYCLO[6.3.0.0(2.7)]UNDECA-3,5-DIENE METAL(0) COMPLEXES OF THE ELEMENTS CHROMIUM, MOLYBDENUM AND TUNGSTEN Özkar, Saim; KREITER, CG (Elsevier BV, 1992-05-01) The hexacarbonyls of chromium, molybdenum, and tungsten react with tricyclo[6.3.0.0(2,7)]undeca-3,5-diene upon UV irradiation in a first step to tetracarbonyl-eta-4-tricyclo[6.3.0.0(2.7)]undeca-3,5-diene-chromium(0) (1), -molybdenum(0) (2) and -tungsten(0) (3). By longer irradiation, dicarbonyl-bis(eta-4-tricyclo[6.3.0.0(2.7)]undeca-3,5-diene)molybdenum(0) (4) and -tungsten(0) (5) are formed. The complexes were purified by chromatography and studied by IR, H-1, and C-13 NMR spectroscopy. The C-13 NMR signal...
Aminophosphine-palladium(II) complexes: Synthsesis, structure and applications in Suzuki and Heck cross-coupling reactions AYDEMİR, MURAT; BAYSAL, AKIN; ŞAHİN, Ertan; Gumgum, Bahattin; Özkar, Saim (Elsevier BV, 2011-11-30) Reaction of furfurylamine with 1 or 2 equivalents of PPh2Cl in the presence of Et3N, proceeds under anaerobic conditions in thf to give furfuryl-2-(N-diphenylphosphino)amine, Ph2PNHCH2-C4H3O, 1 and furfuryl-2-(N,N-bis(diphenylphosphino)amine), (Ph2P)(2)NCH2-C4H3O, 2, respectively. The reactions of 1 and 2 with MCl2(cod) (M = Pd, Pt; cod = 1,5-cyclooctadiene) or Pt(CH3)(2)(cod) yield complexes [M(Ph2PNHCH2-C4H3O)(2)Cl-2] (M= Pd 1a, Pt 1b), [Pt(Ph2PNHCH2-C4H3O)(2)(CH3)(2)] (1c), and [M((Ph2P)(2) NCH2-C4H3O)Cl...
Coupling of ferrocenyl chromium carbene complex with cyclobutenediones Zora, Metin; Bekir Peynircioglu, N. (Elsevier BV, 2002-08-15) The coupling of ferrocenyl chromium carbene complex with cyclobutenediones leads to ferrocenyl-substituted 5-alkylidenefuranones and 4-cyclopentene-1,3-diones, methyl ferrocenoate and acetylferrocene in varying amounts. The scope and limitations of these processes are investigated. In comparison with the phenyl analog, ferrocenyl chromium carbene complex has been found to be less reactive. This is also supported by PM3 calculations. The coupling of ferrocenyl chromium carbene complex with cyclobutenediones...
Chemoenzymatic synthesis of enantiomerically enriched 2-oxobicyclo[m.1.0]alkan-3-yl acetate derivatives ÖZDEMİRHAN, FAZİLET DEVRİM; ÇELİK, MURAT; ATLI, SELİN; Tanyeli, Cihangir (Elsevier BV, 2006-01-23) Racemic alpha'-acetoxy alpha,beta-unsaturated cyclopentanone and cyclohexanone have been resolved into the corresponding enantiomerically enriched alpha'-hydroxylated and acetoxylated compounds with 96-97% ee via PLE hydrolysis. Stereoselectivity in the palladium(II)-catalyzed reaction between the enantiomerically enriched alpha'-acetoxylated compounds and diazomethane has been investigated. In the alpha'-acetoxylated cyclopentenone, preferential cyclopropanation occurs in the anti-form, whereas alpha'-acet...
Synthesis and characterization of new (N-diphenylphosphino)-isopropylanilines and their complexes: crystal structure of (Ph2P = S)NH-C6H4-4-CH(CH3)(2) and catalytic activity of palladium(II) complexes in the Heck and Suzuki cross-coupling reactions AYDEMİR, MURAT; BAYSAL, AKIN; GÜRBÜZ, NEVİN; ÖZDEMİR, İSMAİL; Gumgum, Bahattin; Özkar, Saim; Caylak, Nagihan; Yildirim, Leyla Tatar (Wiley, 2010-01-01) Three new (N-diphenylphosphino)-isopropylanilines, having isopropyl substituent at the carbon 2- (1) 4- (2) or 2,6- (3) were prepared from the aminolysis of chlorodiphenylphosphine with 2-isopropylaniline,4-isopropylaniline or 2,6-diisopropylaniline, respectively, under anaerobic conditions. Oxidation of 1,2 and 3 with aqueous hydrogen peroxide, elemental sulfur or gray selenium gave the corresponding oxides, sulfides and selenides (Ph2P=E)NH-C6H4-2-CH(CH3)(2), (Ph2P=E)NH-C6H4-4-CH(CH3)(2) and (Ph2P=E)NH-C6...

Citation Formats

M. KOTZIAN, C. KREITER, G. MICHAEL, and S. Özkar, “HINDERED LIGAND MOTIONS IN TRANSITION-METAL COMPLEXES .18. SYNTHESIS AND DYNAMIC BEHAVIOR OF TRICARBONYL(ETA-DIENE)(TRIMETHYLPHOSPHANE)CHROMIUM(0) AND TRICARBONYL(ETA-DIENE)(TRIMETHYL PHOSPHITE)CHROMIUM(0),” CHEMISCHE BERICHTE-RECUEIL, pp. 3637–3658, 1983, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/69982.