Triorganosiloxy and tetraphenyldisiloxydiolate complexes of the heavier alkaline-earth metals. Crystal structures of [Sr-3(tmhd)(3)(OSiPh3)(3)]center dot 0.5C(6)H(5)Me (tmhd = 2,2,6,6-tetramethylheptane-3,5-dionate) and [Sr-2{O(SiPh2O)(2)}(3)(tetraglyme)(2)]center dot 0.5C(6)H(5)Me [tetraglyme = CH3O(CH2CH2O)(4)CH3]

Strontium or barium metal granules reacted with an excess of HOSiMe2But in an ammoniacal toluene solution at -40 degrees C to produce the corresponding [M(OSiMe2But)(2)](n). The strontium complex was also obtained from silanolysis of the strontium ethoxide [{Sr(OEt)(2)(HOEt)(4)}(n)] with an excess of HOSiMe2But in hot toluene solution, Similarly, the reaction of [{Sr(OEt)(2)(HOEt)(4)}(n)] in hot toluene, with 1 molar equivalent of HOSiPh3 and Htmhd (2,2,6,6-tetramethylheptane-3,5-dione) yielded the trimeric complex [Sr-3(tmhd)(3)(OSiPh3)(3)].0.5C(6)H(5)Me. The reaction of strontium or barium metal granules with 2 molar equivalents of diphenylsilanediol [Ph2Si(OH)(2)] in ammoniacal toluene solution at -40 degrees C yielded the polymeric complexes [{M[O(SiPh2O)(2)](H2O)(NH3)(x)}(n)] [M = Ca (x = 0.3), Sr (x = 1) or Ba (x = 0.3)]. Similar reactions for strontium and barium in the presence of an excess of hmpa [OP(NMe2)(3)] produced [Sr-3{O(SiPh2O)(2)}(3)(hmpa)(5)].C6H5Me and [Ba-3{O(SiPh2O)(2)}(3)(hmpa)(5).(H2O)], respectively Alternatively, when these reactions were performed in the presence of tetraglyme [CH3O(CH2CH2O)(4)CH3] the water- and NH3-free complexes [M-3{O(SiPh2O)(2)}(3)(tetraglyme)(2)].0.5C(6)H(5)Me were obtained (M = Sr or Ba). All complexes have been characterised by elemental analyses and IR, NMR (H-1, C-13 and Si-29, in selected cases P-31) spectroscopy and also by TGA/DSC studies. The complexes [Sr-3(tmhd)(3)(OSiPh3)(3)].0.5C(6)H(5)Me and [Sr-3{O(SiPh2O)(2)}(3)(tetraglyme)(2)].0.5C(6)H(5)Me have been characterised by X-ray crystallography. The structure of the former reveals a trimer of strontium cations stabilised by three tmhd ligands, and one mu- and two mu(3),-bridging triphenylsiloxy ligands. Relatively short Sr...C (methyl) and Sr...C (phenyl) contacts have also been identified in this compound. In contrast, the three strontium cations in the latter are arranged in an almost linear array within a Sr3O9Si6 core.