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Ke-yan Lian Yuan-fei Jiang De-hou Fei Wei Feng Ming-xing Jin Da-jun Ding Yi Luo 《化学物理学报(中文版)》2012,25(2):147-152
With the concept of super-atom, first principles calculations propose a new type of super stable cage clusters AlnH3n that are much more energetic stable than the well established clusters, AlnHn+2. In the new clusters, the aluminum core-frame acts as a super-atom with n vertexes and 2n Al-Al edges, which allow to adsorb n hydrogen atoms at the top-site and 2n at the bridge-site. Using Al12H36 as the basic unit, stable chain structures, (Al12H36)m, have been constructed following the same connection mechanism as for (AlH3)n linear polymeric structures. Apart from high hydrogen percentage per molecule, calculations have shown that these new clusters possess large heat of formation values and their combustion heat is about 4.8 times of the methane, making them a promising high energy density material. 相似文献
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Meng-hui Wang De-hou Fei Chen Chen Yu-qian Liu Prof. Dr. Sudip Pan Prof. Dr. Zhong-hua Cui 《Chemphyschem》2023,24(15):e202300257
The achievement of the rule-breaking planar hypercoordinate motifs (carbon and other elements) is mainly attributed to a practical electronic stabilization mechanism, where the bonding of the central atom pz π electrons is a crucial issue. We have demonstrated that strong multiple bonds between the central atom and partial ligands can be an effective approach to explore stable planar hypercoordinate species. A set of planar tetra-, penta- and hexa-coordinate silicon clusters were herein found to be the lowest-energy structure, which can be viewed as decorating SiO3 by alkali metals in the MSiO3−, M2SiO3 and M3SiO3+ (M=Li, Na) clusters. The strong charge transfer from M atoms to SiO3 effectively results in [M]+SiO32−, [M2]2+SiO32− and [M3]3+SiO32− salt complexes, where the Si−O multiple bonding and structural integrity of the Benz-like SiO3 framework is maintained better than the corresponding SiO32− motifs. The bonding between M atoms and SiO3 motif is best described as M+ forming a few dative interactions by employing its vacant s, p, and high-lying d orbitals. These considerable M←SiO3 interactions and Si−O multiple bonding give rise to the highly stable planar hypercoordinate silicon clusters. 相似文献
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多组份含金属盐透明树脂的合成 总被引:2,自引:0,他引:2
本文将双烯聚醚砜大分子单体(BPS-MA)引入含金属(Pb、Ba等)盐单体的苯乙烯体系中进行聚合,发现单体配比与树脂透明性密切相关。对于Pb(MA)_2/St/MA/BPS-MA四元体系,欲获得透明树脂,BPS-MA用量大于20%时,摩尔比MA/[Pb(MA)_2]可由原来的5.5降至2.2左右,并且可获得n_D>1.60的透明材料。光学性能测试结果表明,Pb(MA)_2、BPS-MA量增加,n_D增大,阿贝数v_D略降低;MA量增加,n_D下降v_D略增加。适当的配比可望制备出性能优异的多组份含金属盐透明聚合物材料。 相似文献
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用光子相关光谱研究了四臂星形聚苯乙烯在良溶剂(四氢呋喃THF)和θ溶剂(环己烷CH)中扩散系数与溶剂的浓度和温度的依赖关系。用累积量方法分析光子相关数据给出了多分散样品的Z均扩散系数。在θ溶剂中,高于或低于θ温度时,聚合物在溶液中的分子扩散分别表现出具有在良溶剂与不良溶剂中的行为。外推浓度至零,得到无限稀时不同温度的分子扩散系数,借助Stokes-Einstein方程,给出了聚合物的流体力学半径。通过InD对I/T作图,得到了星形聚苯乙烯在THF与CH中的扩散活化能。 相似文献
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多组分含金属透明树脂的结构与性能 总被引:1,自引:0,他引:1
研究了苯乙烯(St)、聚醚砜双烯大分子单体(PES-3-MA)、甲基丙烯酸铅[Pb(MA)_2]、桂皮酸钡[Ba(CA)_2]等多元共聚透明树脂的结构与性能的关系。实验结果表明:随PES-3-MA及Pb(MA)_2含量的增加,树脂的线膨胀系数α下降,树脂的密度却增大;间接求得D_(4P(PES-3-MA)~(20)=1.330、D_(4P(PSU-3-MA)~(20)=1.200、D_(4P[Pb(MA)_2]~(20)=2.100;PES-3-MA含量增加,树脂的硬度增大;Pb(MA)_2量增加,硬度下降;耐热性与不含Pb(MA)_2相比提高30~40℃。光声光谱研究表明悬吊双键需经较高温度的热处理才能进一步反应完全。 相似文献
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Zhou Zhi-xu Wu Qing-mei Huang Zhu-yan Yu De-hou Lu Hong-guang 《Research on Chemical Intermediates》2021,47(9):3609-3627
Research on Chemical Intermediates - In this study, the compound 4-(2-chlorobenzyl)-1-(5-fluoro-2-hydroxy-3-((4-methylpiperidin -1-yl)methyl)phenyl)-[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one (1)... 相似文献
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