Carbonyl-bis-{6,6'-[(3,3'-di-tert-butyl-5,5'-dimeth-oxy-1,1'-biphenyl-2,2'-di-yl)bis(oxy)]bis-(dibenzo[d,f][1,3,2]-dioxaphosphepine)}hydridorhodium(I) toluene-d 8 2.25-solvate.

The crystal-structure determination of the title compound, [RhH(C46H44O8P2)2(CO)]·2.25C7D8, is reported. The bis-phosphite ligand, C46H44O8P2, is well known as Biphephos. One specific characteristic of this hydrido rhodium(I) monocarbonyl complex is that one bis-phosphite ligand is coordinated in the expected bidentate mode and the other is coordinated in a monodentate mode. Thus, one phosphite moiety remains non-coordinating. All three coordinating phospho-rus atoms occupy the equatorial positions in the trigonal-bipyramidal environment around the rhodium atom. The crystals of the hydrido rhodium(I) monocarbonyl complex contains deuterated solvent mol-ecules (toluene-d 8). Most of them are included in the model, but the contributions of about 0.84 toluene per unit cell were removed from the diffraction data, using the SQUEEZE procedure in PLATON [Spek (2015 ▸). Acta Cryst. C71, 9-18].