USE OF THE 2,4,6-TRIS(TRIFLUOROMETHYL)PHENYL LIGAND IN ORGANOGALLIUM CHEMISTRY

The compounds [R(F)Ga(mu-Cl)Cl]2 (1), [(R(F))2Ga(mu-Cl)]2 (3), and (R(F))3Ga (4) (R(F)) = 2,4,6-(CF3)3C6H2) have been prepared by treatment of the aryllithium reagent [R(F)Li.Et2O]2 with gallium trichloride. The hydroxy derivative [R(F)Ga(mu-OH)Cl]2 (2) was obtained as a hydrolysis product of 1. All compounds have been characterized by elemental analysis and multinuclear NMR and mass spectroscopy. X-ray crystallographic studies reveal that compound 1 adopts a chloride-bridged dimeric structure in which the gallium atoms are tetrahedrally coordinated and that 4 is monomeric and features a trigonal-planar geometry at gallium. X-ray analysis reveals a hydroxy-bridged dimeric structure for 2. Single-crystal data are as follows: [R(F)-Ga(mu-Cl)Cl]2 (1), orthorhombic, Pbca, with a = 9.569(2) angstrom, b = 16.787(1) angstrom, c = 16.608(3) angstrom, V = 2667.9(7) angstrom3, Z = 4, and R = 0.0543 (R(w) = 0.0602); [R(F)Ga(mu-OH)Cl]2 (2), triclinic, P2(1/n), with a = 8.063(1) angstrom, b = 18.335(3) angstrom, c = 24.234(3) angstrom, beta = 90.21(1)-degrees, V = 3582.6(8) angstrom3, Z = 4, and R = 0.0521 (R(w) = 0.114); (R(F))3Ga (4), triclinic, P1BAR, with a = 8.808(2) angstrom, b = 12.764(2) angstrom, c = 14.184(2) angstrom, alpha = 97.69(1)-degrees, beta = 95.19(1)-degrees, gamma = 106.46(1)-degrees, V = 1501.5(4) angstrom3, Z = 2, and R = 0.0434 (R(w) = 0.0507). In general, it was found that the air stability and volatility of the new compounds increased with the degree of R(F) substitution. Compounds 2 and 4 are stable to moist air.