Synthesis of Mononuclear Strontium Complexes with Polyether and β-Diketonato Ligands.

Strontium β-diketonate complexes were synthesized by the substitution reaction of the bis(trimethylsilyl) amide of Sr(btsa)·2DME with an ethereal group and β-diketonate ligands. The compounds [Sr(tmge)(btsa)] (), [Sr(tod)(btsa)] (), Sr(tmgeH)(tfac) (), Sr(tmgeH)(acac) (), Sr(tmgeH)(tmhd) (), Sr(todH)(tfac) (), Sr(todH)(acac) (), Sr(todH)(tmhd) (), Sr(todH)(hfac) (), Sr(dmts)(hfac) (), [Sr(mee)(tmhd)] (), and Sr(dts)(hfac)·DME () were obtained and analyzed by various techniques, including FT-IR, NMR, TGA (thermogravimetric analyses), and elemental analysis. Complexes , , , , , , and were further structurally confirmed by single-crystal X-ray crystallography, where complexes and showed dimeric structures with μ-O bonds of ethereal groups or tmhd ligands, and complexes , , , , and displayed monomeric structures. Interestingly, compounds and , which preceded trimethylsilylation of the coordinating ethereal alcohols such as tmhgeH and meeH in the presence of HMDS as by-products due to highly increasing acidity of them, originated from electron-withdrawing two hfac ligands.