Synthesis and Crystal Structures of New Strontium Complexes with Aminoalkoxy and β‑Diketonato Ligands

New heteroleptic
strontium complexes were synthesized using substitution
reaction of bis­(trimethylsilyl)­amide of Sr­(btsa)2·2DME
with aminoalkoxide and β-diketonate ligands. The complexes [Sr­(bdmp)­(btsa)]2·2THF (1), [Sr­(bdeamp)­(btsa)]2 (2), [Sr­(dadamb)­(btsa)]2 (3), [Sr­(bdmp)­(hfac)]3 (4), [Sr­(bdeamp)­(hfac)]3 (5), [Sr­(dadamb)­(hfac)]3 (6), and [Sr3(dadamb)4(tmhd)2] (7) were prepared and characterized by means of various analysis
techniques such as Fourier transform infrared, NMR, thermogravimetric
analysis, and elemental analysis. Complexes 1–3 were further structurally confirmed by single-crystal X-ray crystallography,
and they displayed dimeric structures in which strontium atoms were
connected by alkoxide oxygen atoms of the μ2 type.
Compound 1 has a trigonal prismatic structure, whereas 2 and 3 have a distorted square pyramidal structure.
In complexes 5–7, trimeric structures were obtained
with strontium atoms connected by μ3–O bonds
of alkoxide oxygen atoms and μ2–O bonds of
alkoxide and β-diketonate oxygen atoms. The crystal structures
of 5, 6, and 7 showed distorted
capped octahedral geometry, while 7 (middle Sr atom)
displayed a distorted trigonal prism geometry. Complexes 5–7 displayed ∼70% mass loss in the temperature range from 25
to 315 °C.