X-ray crystal structure and 13C NMR spectra of [WI2(CO)3(NCMe)2

Abstract

Abstract The X-ray crystal structure of [WI 2 (CO) 3 (NCMe) 2 ] ( 1 ) was determined and the crystals are orthorhombic with a = 12.405(8), b = 7.590(8), c = 13.844(12) A. X-ray data for 911 independent reflections above background were collected on a diffractometer and the structure determined by Fourier methods and refined to R = 0.074. The tungsten geometry is capped octahedral with a carbonyl ligand in the unique capping position. The iodide ligands are trans to each other with the two acetonitrile and octahedral carbonyl ligands cis to each other. The low temperature (−70°C, CD 2 Cl 2 ) 13 C NMR spectrum of ( 1 ) showed carbonyl resonances at δ = 202.36 and 228.48 ppm with an intensity ratio of 2 : 1. The resonance at lower field can be ascribed to the carbonyl ligand in the unique capping position. However, the room temperature 13 C NMR spectrum of ( 1 ) shows a single carbonyl resonance at δ = 219.65 ppm.