Differential scanning calorimetry (DSC) measurements of 37 polycrystalline LaH x (2 0<x <3 0) were performed in this work. Samples were synthesized by a direct reaction of a metal with hydrogen at temperat...Differential scanning calorimetry (DSC) measurements of 37 polycrystalline LaH x (2 0<x <3 0) were performed in this work. Samples were synthesized by a direct reaction of a metal with hydrogen at temperatures higher than 250 ℃ (depending on the final composition). DSC measurements were performed in the temperature range of 110～400 K. For the samples in the range of 2 13< x <2 40 single DSC peaks were detected. In the composition range x >2 45 much more complicated DSC signals (double, triple etc. peaks) were observed which some of them were up to 4 phase transformations. Based on these measurements and carried out on high purity samples and supported by high accuracy hydrogen content determination, a new T-x phase diagram for 110< T <400 K and 2< x <3(LaH x ) was proposed. This new phase diagram shows an up to now unknown complexity phase relationships with the existence of at least 11 of phases at T <400 K.展开更多
从(-)-α-蒎烯氧化制得的(+)-2-羟基蒎-3-酮[(+)-1],经还原得到的顺-(-)-和反-(-)-蒎烷-2,3-二醇[(-)-2和(-)-3];(+)-1与Grignard试剂反应制得的顾-3β-烃基蒎烷-2,3-二醇,烃基为甲基[(-)-4)、苯基[(+)-5]和苄基[(-)-6];以及自(+)-α-...从(-)-α-蒎烯氧化制得的(+)-2-羟基蒎-3-酮[(+)-1],经还原得到的顺-(-)-和反-(-)-蒎烷-2,3-二醇[(-)-2和(-)-3];(+)-1与Grignard试剂反应制得的顾-3β-烃基蒎烷-2,3-二醇,烃基为甲基[(-)-4)、苯基[(+)-5]和苄基[(-)-6];以及自(+)-α-蒎烯制得的(-)-1的(-)N-(β-羟乙基)酮亚胺[(-)-7]。用2～7修饰LiAlH_4制成手性试剂LiAlH_2(?)P~*,并使之还原苯乙酮。从得到的产物α-苯乙醇的e. e. ％值差别归纳出了有关这一类手性试剂的3个在结构上的要点。展开更多
文摘Differential scanning calorimetry (DSC) measurements of 37 polycrystalline LaH x (2 0<x <3 0) were performed in this work. Samples were synthesized by a direct reaction of a metal with hydrogen at temperatures higher than 250 ℃ (depending on the final composition). DSC measurements were performed in the temperature range of 110～400 K. For the samples in the range of 2 13< x <2 40 single DSC peaks were detected. In the composition range x >2 45 much more complicated DSC signals (double, triple etc. peaks) were observed which some of them were up to 4 phase transformations. Based on these measurements and carried out on high purity samples and supported by high accuracy hydrogen content determination, a new T-x phase diagram for 110< T <400 K and 2< x <3(LaH x ) was proposed. This new phase diagram shows an up to now unknown complexity phase relationships with the existence of at least 11 of phases at T <400 K.
文摘从(-)-α-蒎烯氧化制得的(+)-2-羟基蒎-3-酮[(+)-1],经还原得到的顺-(-)-和反-(-)-蒎烷-2,3-二醇[(-)-2和(-)-3];(+)-1与Grignard试剂反应制得的顾-3β-烃基蒎烷-2,3-二醇,烃基为甲基[(-)-4)、苯基[(+)-5]和苄基[(-)-6];以及自(+)-α-蒎烯制得的(-)-1的(-)N-(β-羟乙基)酮亚胺[(-)-7]。用2～7修饰LiAlH_4制成手性试剂LiAlH_2(?)P~*,并使之还原苯乙酮。从得到的产物α-苯乙醇的e. e. ％值差别归纳出了有关这一类手性试剂的3个在结构上的要点。
