Compounds containing the [Zr 6Cl 18H 4] 4− cluster anion

Abstract

Substitution of phosphine ligands in compounds [Zr 6Cl 14H 4(PR 3) 4] with Cl − results in the rapid formation of compounds containing [Zr 6Cl 18H 4] 4−. Compounds [PPh 4] 4[Zr 6Cl 18H 4] ( 2b) and [NEt 4] 4[Zr 6Cl 18H 4] ( 2c) were isolated from the reaction of [Zr 6Cl 14H 4(PMe 3) 4] with [PPh 4]Cl and [NEt 4]Cl, respectively. Compounds [Zr 6Cl 14H 4(PR 3) 4] are intrinsically unstable in solution, and are converted gradually into [HPR 3] 4[Zr 6Cl 18H 4] ( 2e, R = Me; 2f, R = Pr; 2g, R = Bu). When [NBu 4]Cl was present, the decomposition of [Zr 6Cl 14H 4(PMe 3) 4] in MeCN resulted in the isolation of [NBu 4] 4[Zr 6Cl 18H 4] ( 2d). [MePEt 3] 2[PPh 4] 2[Zr 6Cl 18H 4] ( 2h) was obtained from the reaction of [Zr 6Cl 14H 4(PEt 3) 4] with [PPh 4]Cl in CH 2Cl 2. The phosphonium cation [MePEt 3] + was derived from the reaction of PEt 3 with CH 2Cl 2 and residual HSnBu 3 in the solution. [Zr 6Cl 18H 4] 4− was also isolated in the form of a minor product, [Et 3NCH 2Ph] 6[ZrCl 6][Zr 6Cl 18H 4] ( 2a), from the reaction of ZrCl 4 with HSnBu 3 followed by addition of [Et 3NCH 2Ph]Cl. 1H NMR spectra of compounds 2a–2h showed there are four cluster hydrogen atoms in the cluster anion, [Zr 6Cl 18H 4] 4−. Compounds 2a–2e and 2h were also characterized by X-ray single crystal diffraction. In compounds 2a, 2d and 2h, four cluster hydrogen atoms were found to be distributed slightly inside the centers of all eight triangular faces of the Zr 6 octahedron. Compound 2a·4MeCN crystallized in the triclinic space group P 1 with cell dimensions (−60°C) of a = 12.868(3), b = 13.605(3), c = 20.534(3) A ̊ , α = 93.46(2), β = 106.19(1), γ = 117.94(2)°, V = 2972(1) A ̊ 3, and Z = 1 . Compound 2b·4MeCN crystallized in the triclinic space group P 1 with cell dimensions(−60°C) of a = 14.468(2), b = 16.027(3), c = 13.435(3) A ̊ , α = 104.51(9), β = 91.91(2), γ = 72.18(1)°, V = 2853.5(6) A ̊ 3, and Z = 1 . Compound 2c·2MeCN crystallized in the monoclinic space group P2 1/ n with cell dimensions (−60°C) of a = 13.032(2), b = 13.283(4), c = 20.550(5) A ̊ , β = 104.22(2)°, V = 3448(1) A ̊ 3 , and Z = 2. Compound 2d crystallized in the monoclinic space group P2 1/ c with cell dimensions (−60°C) of a = 14.795(3), b = 14.923(7), c = 21.900(4) A ̊ , β = 93.28(1)°, V = 4827(3) A ̊ 3, and Z = 2 . Compound 2e·4MeCN crystallized in the orthorhombic space group F2 mm with cell dimensions (20°C) of a = 26.924(2), b = 38.489(3), c = 24.703(2) A ̊ , V = 25599(3) A ̊ 3, and Z = 16 . Compound 2h·2CH 2Cl 2 crystallized in the triclinic space group P 1 with cell dimensios (20°C) of a = 13.317(2), b = 14.731(3), c = 13.258(3) A ̊ , α = 108.09(2), β = 119.22(3), γ = 86.11(3)°, V = 2146.7(7) A ̊ 3, and Z = 1 .