Teaching Reading Strategies to Students who Study Foreign Languages

Abstract

New mono- and binuclear titanium imido complexes supported by tetradentate, dianionic N(2)O(2)-donor Schiff base ligands were prepared in good yield from the readily available [Ti(NBu(t))Cl(2)(py)(3)] (1a). Thus treatment of 1a with Na(2)[substituted-salen] gave monomeric [Ti(NBu(t))(substituted-salen)] where substituted-salen = Et(2)salen (2) or Bu(t)(4)salen (4). In contrast, the binuclear complex [Ti(NBu(t)){&mgr;-(MeO)(2)salen}](2) (5) was obtained from 1a and Na(2)[(MeO)(2)salen]. The less sterically crowded compounds 2 and 5 undergo tert-butyl imide/arylamine exchange reactions to form [Ti(N-2,6-C(6)H(3)Me(2))(Et(2)salen)] (3) and [Ti(N-2,6-C(6)H(3)Me(2)){&mgr;-(MeO)(2)salen}](2) (6), respectively, whereas 4 does not exhibit this kind of reactivity. The compound 3 can also be obtained directly from Na(2)[Et(2)salen] and [Ti(N-2,6-C(6)H(3)Me(2))Cl(2)(py)(3)] (1b). Crystal data for 3: triclinic, P&onemacr;, a = 12.216(4) Å, b = 12.312(11) Å, c = 17.246(2) Å, alpha = 90.352(12) degrees, beta = 102.59(2) degrees, gamma = 104.96(2) degrees, V = 2440.3(8) Å(3), Z = 4, R = 0.051, R(w) = 0.066 for 7011 data with I > 2sigma(I). Crystal data for 5.CH(2)()Cl(2)(): orthorhombic, Pbca, a = 14.747(4) Å, b = 17.042(4) Å, c = 20.545(3) Å, V = 5163.5(13) Å(3), Z = 4, R(1) = 0.096, wR(2) = 0.086 for 3765 data with I > 2sigma(I). Crystal data for 6: monoclinic, C2/c, a = 17.902(5) Å, b = 12.411(4) Å, c = 21.068(5) Å, beta = 90.27(2) degrees, V = 4681(2) Å(3), Z = 4, R = 0.034, R(w)() = 0.039 for 3633 data with I > 2sigma(I).