Reactions of transition-metal .sigma.-acetylides. 11. Cycloaddition reactions with 1,1-dicyano-2,2-bis(trifluoromethyl)ethene. X-ray structures of [cyclic] W{C:CPhC(CF3)2C(CN)2}(CO)3(.eta.-C5H5), [cyclic] Mn{C:CPhC(CF3)2C(CN)2}(CO)3(dppe), and [cyclic] Fe{C:CPhC(CF3)2C(CN)2}(CO)2(.eta.-C5H5) and of a hydration product, [cyclic] W{NH:C(OH)C(CN):CCPh:C(CF3)2}(CO)2(.eta.-C5H5).cntdot.H2O