Activation of tri(2-furyl)phosphine at a dirhenium centre: Formation of phosphido-bridged dirhenium complexes

Reaction of tri(2-furyl) phosphine (PFu(3)) with [Re-2(CO)(10) (n)(NCMe)(n)] (n = 1, 2) at 40 degrees C gave the substituted complexes [Re-2(CO)(10) (n)(PFu(3))(n)] (1 and 2), the phosphines occupying axial position in all cases. Heating [Re-2(CO)(10)] and PFu(3) in refluxing xylene also gives 1 and 2 together with four phosphido-bridged complexes; [Re-2(CO)(8) (n)(PFu(3))(n)(mu-PFu(2))(mu-H)] (n = 0, 1, 2) (3-5) and [Re-2(CO)(6)(PFu(3))(2)(mu-PFu(2))(mu-Cl)] (6) resulting from phosphorus-carbon bond cleavage. A series of separate thermolysis experiments has allowed a detailed reaction pathway to be unambiguously established. A similar reaction between [Re-2(CO)(10)] and PFu(3) in refluxing chlorobenzene furnishes four complexes which include 1, 2, 6 and the new binuclear complex [Re-2(CO)(6)(eta(1)-C4H3O)(2)(mu-PFu(2))(2)] (7). All new complexes have been characterized by a combination of spectroscopic data and single crystal X-ray diffraction studies. (C) 2009 Published by Elsevier B.V.