HINDERED LIGAND MOVEMENTS IN TRANSITION-METAL COMPLEXES .40. SYNTHESIS AND DYNAMIC BEHAVIOR OF TRICARBONYL-ETA-4-TRICYCLO[6.3.0.0(2.7)]UNDECA-3,5-DIENE-TRIMETHYLPHOSPHITE-METAL(0) AND DICARBONYL-ETA-4-TRICYCLO[6.3.0.0(2.7)]UNDECA-3,5-DIENE-BIS(TRIMETHYLPHOSPHITE)-METAL(0) COMPLEXES OF CHROMIUM, MOLYBDENUM AND TUNGSTEN


KREITER C., KOTZIAN M., ÖZKAR S. , ABUMOUR I.

JOURNAL OF ORGANOMETALLIC CHEMISTRY, vol.431, no.2, pp.159-170, 1992 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 431 Issue: 2
  • Publication Date: 1992
  • Doi Number: 10.1016/0022-328x(92)80115-e
  • Title of Journal : JOURNAL OF ORGANOMETALLIC CHEMISTRY
  • Page Numbers: pp.159-170

Abstract

Tricarbonyl-eta-4-tricyclo[6.3.0.02.7]undeca-3,5-diene-trimethylphosphite-metal(0) and cis-dicarbonyl-eta-4-tricyclo[6.,3.0.02,7]undeca-3,5-diene-bis(trimethylphosphite)metal(0) complexes of chromium (1,4), molybdenum (2,5) and tungsten (3,6) have been prepared photochemically in high yields from the corresponding pentacarbonyl-trimethylphosphite-meta](0) or tetracarbonyl-bis(trimethylphosphite) metal(0) complexes, respectively, with tricyclo[6.3 .0.02,7 ]undeca-3,5-diene. The stereochemistry of 1-6 was determined by IR and NMR spectroscopy. In the case of tricarbonyl-eta-4-tricyclo[6.3.0.02,7] undeca-3,5-diene-trimethylphosphite-tungsten(0) (3), X-ray crystal and molecular structure analysis confirm the conclusions drawn from the spectroscopic data. The distorted pseudo-octahedral complexes 1-3 are obtained exclusively as f-isomers, and 4-6 as af-isomers. All of them show hindered ligand movements, according to their temperature-dependent NMR spectra. For 1-3 a. carbonyl scrambling, and for 4-6 a rotation of the diene ligand is observed.