Solution Dynamics of Thallium-Metal Carbonyl Compounds Using (205)Tl NMR Spectroscopy.

Abstract

A (205)Tl NMR study to probe the solution structure and dynamics of a series of thallium-containing metal complexes has been conducted. The following compounds were examined: Tl{Co(CO)(4)}(3) (Ia), [BnMe(3)N](3)[Tl{Fe(CO)(4)}(3)] ([BnMe(3)N](3)[Ib]), Tl{M(CO)(3)Cp}(3) (Ic, M = Cr; Id, M = Mo; Ie, M = W), TlFp(3) (If; Fp = CpFe(CO)(2)), [PPN](2)[Tl(2)Fe(6)(CO)(24)] ([PPN](2)[II]), [Et(4)N](2)[Tl(2)Fe(4)(CO)(16)] ([Et(4)N](2)[III]), [Et(4)N][L(2)Tl{Fe(CO)(4)}(2)] ([Et(4)N][IV]: [IVa](-), L(2) = bipy; [IVb](-), L(2) = en; [IVc](-), L(2) = phen; [IVd](-), L(2) = tmeda; [IVe](-), L(2) = dien), [Et(4)N](4)[Tl(4)Fe(8)(CO)(30)] ([Et(4)N](4)[V]), and TlCo(CO)(4) (VI). The (205)Tl NMR technique was used to probe the dynamic behavior of the Tl-metal cluster complexes [II](2-), [III](2-), and [V](4-) in solution and the formation of Lewis base adducts of [III](-), as well as the possibility of formation of carbonylate anion adducts of Ia, Ic, Id, and If. [IVb](-) reacted with acetone and formed, after fortuitous oxidation, [{(CO)(4)FeL(2)'Tl}(2)Fe(CO)(4)] (L(2)' = Me(2)C=NCH(2)CH(2)N=CMe(2)) (VII). The initially formed complex [L(2)'Tl{Fe(CO)(4)}(2)](-) ([Et(4)N][IVf]) was spectroscopically characterized. Additionally, the two known but structurally uncharacterized complexes Ia and If as well as the new complexes [BnMe(3)N](3)[Ib] and VII were characterized by single-crystal X-ray diffraction. Compound Ia crystallizes in the monoclinic space group P2(1)/n with a = 16.855(3) Å, b = 6.7790(10) Å, c = 19.049(4) Å, beta = 113.84(3) degrees, V = 1990.8(6) Å(3), Z = 4, R(1)(F) = 0.0221, and wR(2)(F(2)) = 0.0542 [I > 2sigma(I)]. Compound If was synthesized from K[Fp] and TlCl(3).4H(2)O and crystallizes in the triclinic space group P&onemacr; with a = 10.789(2) Å, b = 14.239(3) Å, c = 16.703(3) Å, alpha = 69.39(3) degrees, beta = 89.50(3) degrees, gamma = 69.07(3) degrees, V = 2223.1(7) Å(3), Z = 4, R(1)(F) = 0.0350, and wR(2)(F(2)) = 0.0877 [I > 2sigma(I)]. Compound [BnMe(3)N](3)[Ib] was synthesized from Na(2)Fe(CO)(4).(3)/(2)diox and Tl(OAc)(3) in MeCN and crystallizes in the hexagonal space group P6(3)/m with a = 18.290(3) Å, c = 8.479(2) Å, V = 2456.4(8) Å(3), Z = 2, R(1)(F) = 0.0235, and wR(2)(F(2)) = 0.0494 [I > 2sigma(I)]. Compound VII crystallizes in the triclinic space group P&onemacr; with a = 13.597(3) Å, b = 15.040(3) Å, c = 10.536(2) Å, alpha = 92.75(3) degrees, beta = 95.07(3) degrees, gamma = 114.40(3) degrees, V = 1946.0(7) Å(3), Z = 2, R(1)(F) = 0.0461, and wR(2)(F(2)) = 0.1295 [I > 2sigma(I)].