racemic-8,8'-Bis(diphenylphosphino)-3,3',4,4'-tetrahydro-4,4,4',4',6,6'-hexamethyl-2,2'-spirobi[2H-1-benzopyran], min. 95% SPANphos

Technical Note:
1.A binucleating diphosphine ligand used as a trans-spanning ligand which rigidly links mutually trans coordination sites via e.g. inMCl,(SPANphos) (M= Pa, Pt), Rhs(u-CI)2(CO)(SPANphos), the latter usefui in, for example, the homogeneous catalyti ; carbonylation of methanol to acetic acid.
References:
1. Angew chem Int Ed..2003 42 1284