Two atropisomers of tricarbonyl[eta6-6-chloro-3-(3-chloro-2-methylphenyl)-2,4,8-trimethyl-1,2,3,4-tetrahydro-2,4-dibora-1,3-diazanaphthlene]-chromium(0)

Acta Crystallogr C. 2001 Jul;57(Pt 7):796-8. doi: 10.1107/s0108270101006187. Epub 2001 Jul 9.

Abstract

The structures of two atropisomers of the title compound, [Cr(C16H18B2Cl2N2)(CO)3], are reported. For both compounds, the Cr(CO)3 moiety is bound to the C6 aromatic ring of the molecule; the existence of atropisomers resulting from the non-equivalence of both faces of the C6 aromatic ring is a consequence of the 3-chloro-2-methylphenyl ring being nearly perpendicular to the mean plane of the 2,4-dibora-1,3-diazanaphthalene ring. The orientation of the Cr(CO)3 tripod relative to the C6 aromatic ring is such that it is nearly eclipsed in one isomer (2.4 degrees rotation from being eclipsed with C--N, C--Cl and C--H) and slightly twisted (16.2 degrees ) from an eclipsed conformation in the other.