The reaction of Sr with Ba and 15-crown-5 and HOSiPh(3) in THF in the presence of NH3, results in formation of the species M(OSiPh(3))(2)(15-crown-5)THF, M = Sr 1 and Ba 2. These species were shown to be among the first examples of monomeric Group 2 siloxide compounds in the solid state by single-crystal X-ray diffraction. Thermally induced reaction in the solid state resulted in loss of the organic supporting ligands by similar to 250 degrees C with formation of MSi(2)O(5), whereas in refluxing toluene, (1) and (2) underwent silyl ether elimination ((Ph(3)Si)(2)O). The reaction of (2) with Ti(O-i-Pr)(4) in toluene solution at 60 degrees C resulted in elimination of Ph(3)Si-O-i-Pr.