Zirconium clusters from the reaction of ZrCl4 with HSnBu(3) followed by addition of phosphines: Zr6Cl14H4(PR(3))(4) compounds

The reduction of ZrCl4 with HSnBu(3) followed by addition of phosphines yields pentanuclear cluster compounds ZT(5)Cl(12)(PR(3))(5)H-4 (2) and three types of hexanuclear cluster compounds, ZT(6)Cl(14)(PR(3))(4)H-4 (3), as well as [Zr6Cl18H5](3-) (4) and a small amount of [Zr6Cl18H4](4-) (5) Separation of these compounds has been achieved by using different solvents in which they have different solubilities and stabilities. The presence of hydrogen atoms and their numbers have been established by 1(H) NMR spectroscopy. The compounds ZT(6)Cl(14)(PR(3))(4)H-4 (3a, R = Me; 3b, R = Et; 3c, R = n-Pr) and [HP(t-Bu)(2)Ph](3)[Zr6Cl18H5] (4d) have been characterized by X-ray crystallography. In compounds 3a and 3b, four hydrogen atoms distributed on the eight triangular faces of the Zr-6 octahedron were located. Compound 3a . 2CH(2)Cl(2) crystallized in the monoclinic space group P2(1)/n with cell dimensions (-75 degrees C) of a 11.149(2) Angstrom, b = 11.049(4) Angstrom, c = 20.666(7) Angstrom, beta = 103.42(2)degrees, V = 2476(1) Angstrom(3), and Z = 2. Compound 3b . 2CH(2)Cl(2) crystallized in orthorhombic space group Pbca with cell dimensions (-60 degrees C) of a = 12.127(3) Angstrom, b = 21.793(5) Angstrom, c = 23.022(4) Angstrom, V = 6084(2) Angstrom(3), and Z = 4. Compound 3c . 2.31C(6)H(6) crystallized in triclinic space group <P(1)over bar> with cell dimensions (-60 degrees C) of a = 12.585(1) Angstrom, b = 13.679(2) Angstrom, c = 23.319(4) Angstrom, alpha = 97.08(2)degrees, beta = 94.77(2)degrees, gamma = 93.30(2)degrees, V = 3960.6(9) Angstrom(3), and Z = 2. Compound 4d . 2CH(2)Cl(2) . 2C(6)H(6) crystallized in monoclinic space group C2/c with cell dimensions (-60 degrees C) of a = 29.432(4) Angstrom, b = 13.503(1) Angstrom, c = 23.892(3) Angstrom, beta = 110.96(1)degrees, V = 8867(2) Angstrom(3), and Z = 4. In compounds 3a-c, six zirconium atoms are arranged in a slightly elongated octahedron with four phosphine ligands at the equatorial positions. The distance of Zr,Zr, Zr-ax(3.359(8) Angstrom) is slightly longer that of Zr-eq-Zr-eq (3.308(6) Angstrom), but both of them are shorter than that found in compound 4d (3.416(2) Angstrom).