Further studies of the isomeric 1,2,7- and 1,3,6-Re2Cl5(PMe(3))(3) compounds

New studies of compounds containing Re2C15(PMe(3))(3) molecules have been carried out on products prepared by one-electron oxidation of Re(II)-Re(II) compounds as well as by one-electron reduction of Re(III)-Re(UI) species. The action of PhI . Cl-2 on Re2Cl4(PMe(3))(4) in 2:1 mole ratio, in the presence of free PMe(3), gives red 1,3,6-/1,2,7-Re2C15(PMe(3))(3) (1) containing two isomers in its unit cell. It was also shown that some additional 1,3,6-Re2Cl5-(PMe(3))(3), isolated as its 1/2CH(2)Cl(2) solvate (2), is always present in the reaction product. The reaction of the quadruply bonded complex [(n-Bu)(4)N]2Re2Cl8 with PMe(3) in propanol at room temperature leads to 1,2,7-Re2Cl5(PMe(3))(3) .(n-Bu)(4)NCl (3). Heating a dichloromethane solution of compound 3 results in pure 1,2,7-Re2Cl5- (PMe(3))(3). All molecules are characterized by a Re-2(5+) core with a sigma(2) pi(4) delta(2) delta* bond of order 3.5 and Re-Re distances within the range 2.210-2.227 Angstrom. Crystal data are as follows: for 1, monoclinic space group P2(1)/c, a = 14.936(5) Angstrom, b = 8.8206(8) Angstrom, c = 34.29(1) Angstrom, beta = 90.77(2)degrees, V = 4517(2) Angstrom(3), Z = 8; for 2, monoclinic space group P2(1)/n, a = 8.907(1) Angstrom, b = 16.112(1) Angstrom, c = 16.683(3) Angstrom, beta = 94.751(6)beta, V = 2385.9(5) Angstrom(3), Z = 4; for 3, triclinic space group P1, a = 8.911(2) Angstrom, b = 10.686(2) Angstrom, c = 10.979(3) Angstrom, alpha = 101.12(2)degrees, beta = 106.82(2)degrees,gamma = 91.29(2)degrees, V = 978.5(4) Angstrom(3), Z = 1.