PREPARATION, CHARACTERIZATION, AND REACTIVITY STUDIES OF CHELATED SUBSTITUTED CYCLOPENTADIENYLMANGANESEDICARBONYL COMPLEXES

Chelates of the parent compounds (eta(5)-C5H4C(O)CH2OCH3)Mn(CO)(3) (1) , (eta(5)-C5H4C(O)CH2SCH3)Mn(CO)(3) (2). (eta(5)-C5H4C(O)CH2CH2SCH3)Mn (CO)(3) (3), (eta(5)-C5H4CH2COOCH3)Mn(CO)(3) (4), and (eta(5)-C5H4CH2C H2COOCH3)Mn(CO)(3) (5) were prepared by photolysis. Only the chelates (eta(1):eta(5)-C5H4C(O)CH2SCH3)Mn(CO)(2) (2chelate) and (eta(1):eta(5) -C5H4C(O)CH2CH2SCH3)Mn(CO)(2) (3chelate) were stable enough to be isol ated. The X-ray structure of 2chelate was determined and demonstrated ring strain in the chelate ring. Derivatives of the chelates were obta ined by thermal substitution of the chelated group. Substitution of th e chelated groups in (eta(1):eta(5)-C5H4C(O)CH2OCH3)Mn(CO)(2) (1chelat e), (eta(1):eta(5)-C5H4CH2COOCH3)Mn(CO)(2) (4chelate), and (eta(1):eta (5)-C5H4CH2CH2COOCH3)Mn(CO)(2) (5chelate) occurred within a few minute s, whereas 2chelate and 3chelate required refluxing for several hours to convert them to the substituted products. The substituted products have the general formula (eta(5)-C(5)H(4)R)Mn(CO)(2)L (where R is the substituent of either 1-5 and L is either a phosphine, phosphite, or t etrahydrothiophene). The weaker Mn-O bond was suggested for the differ ences in the reactivities of the chelated complexes.