STRUCTURAL CHARACTERIZATION OF 2 HAFNIUM(IV) COMPLEXES, HFCL4(PH2PCH2CH2PPH2).2C7H8 AND HFCL4(PH2PCH2CH2CH2PPH2)

(1) [1,2-Bis(diphenylphosphino)ethane-P,P')]tetrachlorohafnium(IV) bistoluene solvate, [HfCl4(C26H24P2)].2C7H8, M(r) = 903.01, monoclinic, C2/c, a = 11.340 (3), b = 18.243 (6), c = 19.661 (3) angstrom, beta = 103.96 (2)-degrees, V = 3947 (3) angstrom 3, Z = 4, D(x) = 1.519 g cm-3, lambda-(Mo K-alpha) = 0.71073 angstrom, mu = 30.0 cm-1, F(000) = 1800, T = 294 K, R = 0.035 for 2079 observed reflections. (2) [1,3-Bis(diphenylphosphino)propane-P,P')]tetrachlorohafnium (IV), [Hf-Cl4(C27H26P2)], M(r) = 732.76, monoclinic, P2(1)/n, a = 12.596 (5), b = 14.117 (2), c = 17.028 (4) angstrom, beta = 109.91 (2)-degrees, V = 2847 (3) angstrom 3, Z = 4, D(x) = 1.710 g cm-3, lambda-(Mo K-alpha) = 0.71073 angstrom, mu = 41.4 cm-1, F(000) = 1432, T = 294 K, R = 0.049 for 1509 observed reflections. In both compounds the coordination around Hf is distorted octahedral with P atoms cis to each other forming five- or six-membered chelate rings. The mean Hf-Cl and Hf-P distances are 2.374 (1) and 2.808 (2) angstrom, and 2.372 (15) and 2.823 (2) angstrom for (1) and (2), respectively. In both compounds the Hf-Cl distances for the Cl atoms trans to the P atoms are somewhat shorter than the other Hf-Cl distances. The P-Hf-P angles for (1) and (2) are 74.80 (5) and 78.5 (2)-degrees, respectively, consistent with the size of the chelate rings.