(Nitrito-κO)(nitro-κN)(nitrosyl-κN)bis-(tri-phenylphosphane-κP)rhodium(III)

The structure of the title compound, [Rh(NO)(NO₂)₂(C₁₈H₁₅P)₂] or [Rh(NO)(NO₂)(ONO)(PPh₃)₂], has been determined by single-crystal X-ray diffraction. A previous report of the title compound showed it crystallized in a monoclinic space group [Rajaseelan et al. (1999 ▸). J. PA. Acad. Sci. 73, 63-66; refcode SASTOW in the CSD]. However, it was unable to be refined because of severe disorder. In this study, two distinct crystals of the title compound were found showing the compound to be polymorphic. One of the crystals was unable to be resolved but was found to be in a monoclinic space group, as in the previously reported study. The other crystal was able to be refined and crystallizes in the triclinic space group P1. The refined structure consists of two discrete monomeric mol-ecules per unit cell. The mol-ecular geometry around rhodium is that of a distorted square pyramid, with nitro-gen of the nitro ligand, oxygen of the nitrito ligand and phospho-rus atoms of the phosphane ligands lying in the basal plane and the nitro-gen atom of the bent nitrosyl occupying the apical position. The nitrosyl ligand exhibits positional disorder whereas the nitro and nitrito ligands show disorder across coordination sites with the disorder modelled in a 0.91:0.09 ratio. Both intra-molecular C-H ⋯O (nitro and nitrito) and inter-molecular C-H ⋯N (nitrito) inter-actions are observed. There are no hydrogen-bonding inter-actions with the N or O atoms of the nitrosyl ligand.