Cyclometallation reactions in complexes of the type Rh(oq)(CO)(P(o-BrC6F4)Ph2): II. The molecular structure of [Rh(oq)Br(P(o-C6F4)Ph2)(H2O)]2 (oq = 8-oxyquinolinate)

The complex [uRh(oq)Br(P(o-Cu₆F₄)Ph₂)(H₂O)]₂ is obtained by refluxing a solution of Rh(oq)(CO)(P(o-BrC₆F₄)Ph₂) (oq = 8-oxyquinolinate) in toluene. The structure of this compound has been determined by X-ray diffraction and refined to R = 0.061 and R_w = 0.065 factors. The cell has monoclinic symmetry, space group P2₁/n; a 19.513(2), b 17.049(1), c 16.898(1) Å and β 99.69(1)°. The structure consists of two independent Rh(oq)Br(P(o-C₆F₄)Ph₂)H₂O) units linked by hydrogen bonds between the coordinated water molecules and oq ligands to form a distorted boat (six atom ring of junction between the two units). In each unit the metal atom has a distorted octahedral coordination, with a four-atom metallocyclic ring (uRhPCCu) with CRhP and RhPC angles 69.3(2) and 85.3(3)°, respectively, in one unit, and 70.0(2) and 81.1(2)° in the other. The water molecule is readily displaced by a variety of phosphorus donor ligands to form the complexes uRh(oq)Br(P(o-Cu₆F₄)Ph₂)P′, P′ = PPh₃, P(p-CH₃C₆H₄)₃ and P(OCH₃)₃, in which the P atoms are in trans-dispositions.