Synthesis and characterization of calcium β-diketonate complexes. X-Ray crystal and molecular structures of: [{Ca(tmhd)2}2(18-crown-6)], [Ca(dpp)2(thf)2] and [Ca(dpp)2(triglyme)]

Abstract

Reactions of 2,2,6,6-tetramethyl-3,5-heptanedione (Htmhd), 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (Hhfa) or 1,3-diphenyl-1,3-propanedione (Hdpp) with calcium methoxide in hexane or toluene afford the corresponding known oligomeric beta-diketonates: [Ca(3)(tmhd)(6)], [{Ca(hfa)(2)}(n)] and [{Ca(dpp)(2)}(n)]. The complexes react with tetrahydrofuran, 2,5,8,11-tetraoxadodecane (triglyme) or 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6) leading to the formation of the new mononuclear [Ca(dpp)(2)(thf)(2)], [Ca(dpp)(2)(triglyme)] and dinuclear [{Ca(dpp)(2)}(2)(18-crown-6)] and [{Ca(tmhd)(2)}(2)(18-crown-6)] adducts. The obtained complexes were characterized by elemental analyses, IR, (1)H and (13)C NMR spectroscopies; moreover, single crystal X-ray diffraction measurements were also carried out for: [{Ca(tmhd)(2)}(2)(18-crown-6)], [Ca(dpp)(2)(thf)(2)] and [Ca(dpp)(2)(triglyme)].

Synthesis and Characterization of Calcium N,N-Dimethylaminodiboranates as Possible Chemical Vapor Deposition Precursors

“…Volatile compounds of the alkaline earth metals are of interest as precursors for the chemical vapor deposition (CVD) of thin films of perovskites, superconductors, and other interesting materials . For the element calcium, a number of coordination complexes are known that can be sublimed without decomposition; among these are the following (sublimation conditions given in parentheses): the cyclopentadienyl complex Ca(C 5 Me 5 ) 2 (75 °C, 10 –4 Torr); the beta-diketiminate complex Ca{[Me 2 N-NC(Me)] 2 CH} 2 (90 °C, 0.05 Torr); the beta-diketonate complexes Ca{[OC(CF 3 )] 2 CH} 2 (140 °C, 10 –3 Torr), , Ca{[OC(C 3 F 7 )] 2 CH} 2 (H 2 O) (160 °C, 40 Torr), Ca[OC(CF 3 )CHC(Me)O] 2 (195 °C, 10 –3 Torr), and Ca{[OC( t -Bu)] 2 CH} 2 L x ; − and pyrazolylborate complexes such as Ca[HB(pz) 3 ] 2 (160 °C, 10 –2 Torr). − …”

Advances in Deposition of Main‐Group Metal Oxides and Rare‐Earth Oxides from Metal Enolates

“…The monomeric calcium enolates [Ca(dpp) 2 (triglyme)] (4) and [Ca(dpp) 2 (thf) 2 ] (4 ′ , dpp = 1,3-diphenyl-1, 3-propanedionate), and the dimeric [Ca(dpp) 2 ] 2 (18-crown-6) and [Ca(thd) 2 ] 2 (18-crown-6) were synthesized to demonstrate that monomeric alkaline-earth species are more volatile than aggregated ones 23 . However, it appeared that the mentioned complexes are unstable during sublimation, decomposing to oligomeric species via elimination, inter alia, of the thf dative-bonded ligands 23 .…”

“…However, it appeared that the mentioned complexes are unstable during sublimation, decomposing to oligomeric species via elimination, inter alia, of the thf dative-bonded ligands 23 .…”

Alkaline and alkaline earth metals

“…158 Reactions of 2,2,6,6-tetramethyl-3,5-heptanedione, 1,1,1,5,5,5-hexafluoro-2,4-pentanedione or 1,3-diphenyl-1,3-propanedione with calcium methoxide have afforded the corresponding known oligomeric b-diketonates. 159 The preparation of several barium b-diketonate complexes with crown-ethers has been described. 160 Alkaline earth metal (Mg Ca Sr and Ba) complexes of hippuric acid (hipH) have been synthesised.…”