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Hydrocarbon-soluble model systems for the calcium-amidoborane-ammine complex Ca(NH(2)BH(3))(2)?(NH(3))(2) were prepared and structurally characterized. The following complexes were obtained by the reaction of RNH(2)BH(3) (R = H, Me, iPr, DIPP; DIPP = 2,6-diisopropylphenyl) with Ca(DIPP-nacnac)(NH(2))?(NH(3))(2) (DIPP-nacnac = DIPP-NC(Me)CHC(Me)N-DIPP): Ca(DIPP-nacnac)(NH(2)BH(3))?(NH(3))(2), Ca(DIPP-nacnac)(NH(2)BH(3))?(NH(3))(3), Ca(DIPP-nacnac)[NH(Me)BH(3)]?(NH(3))(2), Ca(DIPP-nacnac)[NH(iPr)BH(3)]?(NH(3))(2), and Ca(DIPP-nacnac)[NH(DIPP)BH(3)]?NH(3). The crystal structure of Ca(DIPP-nacnac)(NH(2)BH(3))?(NH(3)(3) showed a NH(2)BH(3)(-) unit that was fully embedded in a network of BH???HN interactions (range: 1.97(4)-2.39(4)??) that were mainly found between NH(3) ligands and BH(3) groups. In addition, there were N-H???C interactions between NH(3) ligands and the central carbon atom in the ligand. Solutions of these calcium-amidoborane-ammine complexes in benzene were heated stepwise to 60?°C and thermally decomposed. The following main conclusions can be drawn: 1)?Competing protonation of the DIPP-nacnac anion by NH(3) was observed; 2)?The NH(3) ligands were bound loosely to the Ca(2+) ions and were partially eliminated upon heating. Crystal structures of [Ca(DIPP-nacnac)(NH(2)BH(3))?(NH(3))](∞), Ca(DIPP-nacnac)(NH(2)BH(3))?(NH(3))?(THF), and [Ca(DIPP-nacnac){NH(iPr)BH(3)}](2) were obtained. 3)?Independent of the nature of the substituent R in NH(R)BH(3), the formation of H(2) was observed at around 50?°C. 4)?In all cases, the complex [Ca(DIPP-nacnac)(NH(2))](2) was formed as a major product of thermal decomposition, and its dimeric nature was confirmed by single-crystal analysis. We proposed that thermal decomposition of calcium-amidoborane-ammine complexes goes through an intermediate calcium-hydride-ammine complex which eliminates hydrogen and [Ca(DIPP-nacnac)(NH(2))](2). It is likely that the formation of metal amides is also an important reaction pathway for the decomposition of metal-amidoborane-ammine complexes in the solid state. 相似文献
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Prof. Dr. Sjoerd Harder Dr. Jan Spielmann Briac Tobey 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(7):1984-1991
Hydrocarbon‐soluble model systems for the calcium–amidoborane–ammine complex Ca(NH2BH3)2 ? (NH3)2 were prepared and structurally characterized. The following complexes were obtained by the reaction of RNH2BH3 (R=H, Me, iPr, DIPP; DIPP=2,6‐diisopropylphenyl) with Ca(DIPP‐nacnac)(NH2) ? (NH3)2 (DIPP‐nacnac=DIPP? NC(Me)CHC(Me)N? DIPP): Ca(DIPP‐nacnac)(NH2BH3) ? (NH3)2, Ca(DIPP‐nacnac)(NH2BH3) ? (NH3)3, Ca(DIPP‐nacnac)[NH(Me)BH3] ? (NH3)2, Ca(DIPP‐nacnac)[NH(iPr)BH3] ? (NH3)2, and Ca(DIPP‐nacnac)[NH(DIPP)BH3] ? NH3. The crystal structure of Ca(DIPP‐nacnac)(NH2BH3) ? (NH3)3 showed a NH2BH3? unit that was fully embedded in a network of BH???HN interactions (range: 1.97(4)–2.39(4) Å) that were mainly found between NH3 ligands and BH3 groups. In addition, there were N? H???C interactions between NH3 ligands and the central carbon atom in the ligand. Solutions of these calcium–amidoborane–ammine complexes in benzene were heated stepwise to 60 °C and thermally decomposed. The following main conclusions can be drawn: 1) Competing protonation of the DIPP‐nacnac anion by NH3 was observed; 2) The NH3 ligands were bound loosely to the Ca2+ ions and were partially eliminated upon heating. Crystal structures of [Ca(DIPP‐nacnac)(NH2BH3) ? (NH3)]∞, Ca(DIPP‐nacnac)(NH2BH3) ? (NH3) ? (THF), and [Ca(DIPP‐nacnac){NH(iPr)BH3}]2 were obtained. 3) Independent of the nature of the substituent R in NH(R)BH3, the formation of H2 was observed at around 50 °C. 4) In all cases, the complex [Ca(DIPP‐nacnac)(NH2)]2 was formed as a major product of thermal decomposition, and its dimeric nature was confirmed by single‐crystal analysis. We proposed that thermal decomposition of calcium–amidoborane–ammine complexes goes through an intermediate calcium–hydride–ammine complex which eliminates hydrogen and [Ca(DIPP‐nacnac)(NH2)]2. It is likely that the formation of metal amides is also an important reaction pathway for the decomposition of metal–amidoborane–ammine complexes in the solid state. 相似文献
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Mohanta Antaryami Lanfant Briac Leparoux Marc 《Plasma Chemistry and Plasma Processing》2019,39(5):1161-1179
Plasma Chemistry and Plasma Processing - Synthesis process of graphene nano-flakes produced in radio-frequency inductively coupled plasma system by axially injecting CH4 into Ar–H2 plasma is... 相似文献
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