Crystal structures of 3-ethyl- and 5-ethyl-1,2-dihydro-1-methylpyridine(tricarbonyl)chromium

Abstract

Crystals of the 3-ethyl-complex (III) are orthorhombic, a= 14·999(7), b= 13·263(5), c= 12·164(9)Å. Z= 8, space group Pbca, those of the 5-ethyl-complex (IV) are monoclinic, a= 10·700(3), b= 14·280(6), c= 7·926(3)Å, β= 97·83(4)°, Z= 4, space group P2₁/n. The structures were determined from diffractometer data by Patterson and Fourier methods, and refined by full-matrix least-squares techniques to R 0·039 (III; 916 reflections) and 0·067 (IV; 907 reflections). The chromium atom is bonded to the two double bonds and nitrogen atom of the six-membered ring in both compounds, to give a distorted octahedral co-ordination.