Compounds containing the [Zr6Cl18H4](4-) cluster anion

Substitution of phosphine ligands in compounds [Zr6Cl14H4(PR(3))(4)] with Cl- results in the rapid formation of compounds containing [Zr6Cl18H4](4-). Compounds [PPh(4)](4)[Zr6Cl18H4] (2b) and [NEt(4)](4)[Zr6Cl18H4] (2c) were isolated from the reaction of [Zr6Cl14H4(PMe(3))(4)] with [PPh(4)]Cl and [NEt(4)]Cl, respectively. Compounds [Zr6Cl14H4(PR(3))(4)] are intrinsically unstable in solution, and are converted gradually into [HPR(3)](4)[Zr6Cl18H4] (2e, R = Me; 2f, R = Pr; 2g, R = Bu). When [NBu(4)]Cl was present, the decomposition of [Zr6Cl14H4(PMe(3))(4)] in MeCN resulted in the isolation of [NBu(4)](4)[Zr6Cl18H4] (2d). [MePEt(3)](2)[PPh(4)](2)[Zr6Cl18H4] (2h) was obtained from the reaction of [Zr6Cl14H4(PEt(3))(4)] with [PPh(4)]Cl in CH2Cl2. The phosphonium cation [MePEt(3)](+) was derived from the reaction of PEt(3) with CH2Cl2 and residual HSnBu(3) in the solution. [Zr6Cl18H4](4-) was also isolated in the form of a minor product, [Et(3)NCH(2)Ph]6 [ZrCl6][ZrCl6][Zr6Cl18H4] (2a), from the reaction of ZrCl4 with HSnBu(3) followed by addition of [Et(3)NCH(2)Ph]Cl. H-1 NMR spectra of compounds 2a-2h showed there are four cluster hydrogen atoms in the cluster anion, [Zr6Cl18H4](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 an eight triangular faces of the Zr-6 octahedron. Compound 2a . 4MeCN crystallized in the triclinic space group P (1) over bar with cell dimensions (-60 degrees C) of a=12.868(3), b=13.605(3), c=20.534(3) Angstrom, alpha=93.46(2), beta=106.19(1), gamma=117.94(2)degrees, V=2972(1) Angstrom(3), and Z=1. Compound 2b . 4MeCN crystallized in the triclinic space group P (1) over bar with cell dimensions (-60 degrees C) of a = 14.468(2), b = 16.027(3), c=13.435(3) Angstrom, alpha= 104.51(9), beta=91.91(2), gamma=72.18(1)degrees, V=2853.5(6) Angstrom(3), and Z=1. Compound 2c . 2MeCN crystallized in the monoclinic space group P2(1)/n with cell dimensions (-60 degrees C) of a=13.032(2), b=13.283(4), c =20.550(5) Angstrom, beta = 104.22(2)degrees, V=3448(1) Angstrom(3), and Z= 2. Compound 2d crystallized in the monoclinic space group P2(1)/c with cell dimensions (-60 degrees C) of a=14.795(3), b=14.923(7), c=21.900(4) Angstrom, beta=93.28(1)degrees V=4827(3) Angstrom(3), and Z=2. Compound 2e . 4MeCN crystallized in the orthorhombic space group F2mm with cell dimensions (20 degrees C) of a=26.924(2), b=38.489(3), c=24.703(2) Angstrom, V=25599(3) Angstrom(3), and Z=16. Compound 2h . 2CH(2)Cl(2) crystallized in the triclinic space group P (1) over bar with cell dimensions (20 degrees C) of a = 13.317(2), b = 14.73 1(3), c = 13. 258(3) Angstrom, alpha=108.09(2), beta=119.22(3), gamma=86.11(3)degrees, V=2146.7(7) Angstrom(3), and Z=1.