Chemistry of o-Mercaptophenolate: Syntheses, Structures, and Characterization of Titanium(IV) Complexes

Abstract

Abstract The reaction of Cp2TiCl2 with o-mercaptophenolate in the presence of a base (Et3N or NaOMe) afforded the complex (BnMe3N)2[Ti(o-SC6H4O)3] or (Et4N)2[Ti2(o-SC6H4O)4(OMe)2]·2H2O under slightly varied conditions. Single-crystal X-ray diffraction studies showed that the Ti(IV) geometry in both complexes is a severely distorted octahedron with average trans-angles of 162.2° and 159.1(2)°, respectively. Crystallographic data for (BnMe3N)2[Ti(o-SC6H4O)3]: a = 9.884(3), b = 16.501(7), c = 23.028(7) Å; β = 99.89(3)°, V = 3700.2(22) Å3, Z = 4, final R = 0.050 for 3134 observed reflections; for (Et4N)2[Ti2(o-SC6H4O)4(OMe)2]·2H2O: a = 8.953(4), b = 10.148(3), c = 14.527(3) Å; α = 73.16(2)°, β = 73.00(3)°, γ = 83.56(4)°, V = 1207.4(9) Å3, Z = 1, final R = 0.082 for 2233 observed reflections. The isolation of (BnMe3N)2[Ti(o-SC6H4O)3] provides strong evidence for the synthon character of [Ti(mp)3]2−, which was previously predicted to be present in the complex (Et4N)2[Ti(mp)3Na(MeOH)2]2. Both electronic and 1H NMR spectra showed a similar rigidity of the mp chelate rings to Ti(IV) in the complexes.