X-ray crystal structure of cis-{(±)-6,6′-[[1,1′-biphenyl]-2,2′-diylbis(oxy)]bis–dibenzo[d,f][1,3,2]dioxaphosphepin} diiodoplatinum(II)·dichloromethane

Abstract

Bis(dibenzo[d,f][1,3,2]dixoaphosphepin) ligands are extensively used in catalysts for asymmetric alkene hydroformylation; however, few crystal structures of complexes of these ligands have been reported. In this paper, the synthesis and X-ray crystal structure of cis-{(±)-6,6′-[[1,1′-biphenyl]-2,2′-diylbis(oxy)]bis-dibenzo[d,f][1,3,2]dioxaphosphepin} diiodoplatinum (II)·dichloromethane are presented. This complex crystallizes in the triclinic space group P1¯ with a = 12.0842(2,3) b = 12.6993(15) c = 13.2801(18) A; α = 85.852(10), β = 76.723(13), γ = 72.400(12)°, V = 1890.7(10) A3 and Z = 4. The diastereomer that has crystallized has an R*R*R*(S*S*S*) configuration. This X-ray crystal structure supports previous observations that bis(phosphite) ligands with bridging groups derived from 2,2′-biphenol can exhibit a wide range of bite angles (>20°).