An Unusual sandwich-type nickel oxide-siloxanolate complex {[PhSiO]}6 (μ4-O)2 (μ3-O)4[Ni8(μ3-0)2](μ3-O)4(μ4-O)2 [PhSiO]6}·14n-BuOH·10H2O·2Me2CO. Synthesis and crystal structure