Patent ID: 7491850

Claim:
A bisphosphite represented by formula (I): wherein Ar 1 and Ar 2 are each independently a substituted or an unsubstituted arylene group; R 1 , R 2 , R 7 and R 8 are each independently a substituted or an unsubstituted alkyl group, a substituted or an unsubstituted aryl group or a substituted or an unsubstituted heterocyclic group; and R 3 , R 4 , R 5 and R 6 are each independently a hydrogen atom or an alkyl group, with the proviso that the carbon atom bearing R 3 and R 4 and the carbon atom bearing R 5 and R 6 are bound to their respective arylene groups at the ortho position to the Ar 1 —Ar 2 bond.