The octahedral cluster complex Rh 2Co 2(CO) 10(μ 4, η2 -HC≡CFc) 1 reacts with PPh 3 to give the title cluster Rh 2Co 2(CO) 10-n(μ 4, η2-HC≡CFc)(PPh 3) n(2, n=1; 3, n=2, ). The structure of 3 has been determined by X-ray diffraction. At 60 ℃ and 1.8 MPa of initial total CO/H 2 (1∶1) pressure, the catalytic activity of 3 for hydroformylation of s tyrene has also been investigated. The conversion of the styrene is 98.1%, the selectivity of the aldehydes is 99%, the 3-phenylpropyl aldehyde(n)/2-phenylpropyl aldehyde( i) mole ratio of aldehyde to 1/17.4.