名称:
Synthesis and structural characterization of [HxCp*TiMo5O18](3−x)− (x=0, 1, 2); new insights into protonation patterns in polyoxometalates
摘要:
Reaction Of [(n-C4H9)(4)N](2)[Mo2O7], Cp*TiCl3, and [(n-C4H9)(4)N]OH in CH3CN yields [(n-C4H9)(4)N](3)[Cp*TiMo5O18].CH3CN [a = 12.863(4) Angstrom b = 26.608(6) Angstrom, c = 24.534(4) Angstrom, beta = 103.88(2)degrees, Z = 4, space group P2(1)/c (no. 14)]. Similar reaction without [(n-C4H9)(4)N]OH yields monoprotonated complex [(n-C4H9)(4)N](2)[HCp*TiMo5O18], where, according to a single-crystal X-ray diffraction study [a = 19.9550(4) Angstrom, b = 25.5420(8) Angstrom, c = 11.8820(3) Angstrom, beta = 100.31(2)degrees, Z = 4, space group P2(1)/n (no. 14)], the anion is protonated at one of OMo2 doubly-bridging oxygens. Reaction of [(n-C4H9)(4)N](2)[HCp*TiMo5O18] with CCl3COOH in CHCl3 followed by crystallization from CH3CN/Et2O yields diprotonated [(n-C4H9)(4)N][H2Cp*TiMO5O18].1/4(C2H5)(2)O, which, according to a single-crystal X-ray diffraction study [a = 12.319(2) Angstrom, b = 16.105(3) Angstrom, c = 12.001(2) Angstrom, alpha = 110. 74(1)degrees, beta = 100.31(2)degrees, gamma = 82.777(5) Z = 2, space group P (1) over bar (no. 2)], contains hydrogen-bonded dimers of [H,,Cp*TiMo5O19](-) ions. The [Cp*TiMo5O18](3-) is basic enough to form stable organometallic adducts like [(eta-C8H12)Ir(Cp*TiMo5O18)](2-) and [(eta-C8H14)Rh(Cp*TiMo5O18)](2-). (C) 2003 Elsevier Ltd. All rights reserved.