INTENSELY GREEN QUINONOID [CR(CO)(4)(PH(2)P)(2)C=C6H4=C(R)O(2)CR-P,P]COMPLEXES

Ph(2)PCH(Ph)PPh(2), prepared by treating Ph(2)PCH(2)Ph successively wi th n-BuLi and Ph(2)PCl, reacts with group VI metal hexacarbonyls to gi ve [M(CO)(4){Ph(2)PCH(Ph)PPh(2)}], where M = Cr, Mo or W. The Cr compl ex [Cr(CO)(4){Ph(2)PCH(Ph)PPh(2)}] was deprotonated with MeLi and the resulting carbanion [Cr(CO)(4)(Ph(2)PCPhPPh(2))](-) acylated with RCOC l (R = Ph or p-tolyl) to give the intensely green title compounds in w hich an aromatic ring has become a quinonoid.