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.
Bibliographical noteFunding Information:
We are grateful to the Center for Chemical Analysis at the Korea Research Institute of Chemical Technology (KRICT) for allowing the use of their facilities and Bruker SMART APEX II for solving the crystal structures. This work was supported by the Materials and Components Technology Development Program (20010275, Development of ALD precursors for high k thin film in logic and DRAM Flash memory devices) funded by the Ministry of Trade, Industry & Energy (MOTIE, Republic of Korea) and the Development of smart chemical materials for IoT devices Project through the Korea Research Institute of Chemical Technology (KRICT) of Republic of Korea (SS2121-10).
© 2021 The Authors. Published by American Chemical Society.
ASJC Scopus subject areas
- Chemical Engineering(all)