碳材料用碳源化合物热解机理的理论研究

运用Ｇａｕｓｓｉａｎ９８程序包中的ＡＭ１方法,对间二甲苯系列化合物的热反应活性及热裂解机理进行了研究。通过不同温度下标准热力学量的计算和自在间的轨道能级差的量子化学理论计算,结果表明：（１）当温度低于８００℃时,对各反应物来说热力学支持的主反应路径均是苯环上甲基Ｃ－Ｈ键首先断裂。当温度达到８００℃时,热裂解路径由首先选择Ｃ－Ｈ键的断裂变成首先选择苯环与甲基间Ｃ－Ｃ键的断裂。该结论与实验结果一致;（２）各反应物之间的热反应活性由大到小的顺序为：２,４－二甲基苯酚〉２,４－二甲基－１－巯基苯〉间二甲苯〉２,４－二甲基－１－氰基苯。同时亦说明,自由基之间的前线轨道能级差和热力学量的变化等理论参数一样亦可用于判断间二甲苯系列反应物的热解机理和热反应活性。     

一种新型卟啉侧链聚合物的飞秒荧光动力学

研究了一种新型的卟啉侧链聚合物丙烯腈丙烯酸卟啉酯共聚物{poly[porphyrin acrylate-acrylonitrile](p[(por)A-AN]}的链间和链内的卟啉分子的相互作用对聚合物薄膜发光性质的影响。通过采用飞秒荧光光谱技术测量了p[(por)A-AN]薄膜的荧光动力学过程。测量结果表明:纯p[(por)A-AN]薄膜(~450ps)显示出了比混合物薄膜p[(por)A-AN]/polystyrene(PSE)(~1.3 ns)快得多的荧光弛豫过程。而p[(por)A-AN]/PSE混合物薄膜显示出较纯p[(por)A-AN]薄膜增强的荧光效率。增加p[(por)A-AN]分子内卟啉侧链基团的浓度导致纯p[(por)A-AN]薄膜和p[(por)A-AN]/PSE混合物薄膜的荧光效率的增强和寿命(由近26~36 ps)的增加。分子间和分子内卟啉侧链基团之间的无辐射能量转移和分子内卟啉侧链基团的旋转运动在p[(por)A-AN]的荧光动力学过程中起着重要的作用。     

三元体系YCl3-CdCl2-H2O和四元体系YCl3-CdCl2-HCl(～8.8%)-H2O (25 ℃)的相平衡及其固相新化合物的研究

The equilibrium solubilities of the ternary system YCl₃-CdCl₂-H₂O, the quaternary system YCl₃-CdCl₂-HCl(～8.8%)-H₂O were determined at 25 ℃ and the phase diagrams were constructed. The results show that the ternary system was complicated with six equilibrim solid phases CdCl₂·2.5H₂O, CdCl₂·H₂O, 8CdCl₂·YCl₃·15H₂O (8∶1 type), 4CdCl₂·YCl₃·13H₂O(4∶1 type), 5CdCl₂·2YCl₃·26H₂O (5∶2 type) and YCl₃·6H₂O. The quaternary system was also complicated with four equilibrim solid phase CdCl₂·H₂O, 4CdCl₂·YCl₃·13H₂O (4∶1 type), 5CdCl₂·2YCl₃·26H₂O(5∶2 type) and YCl₃·6H₂O. Among the three new compounds 8CdCl₂·YCl₃·15H₂O, 4CdCl₂·YCl₃·13H₂O and 5CdCl₂·2YCl₃·26H₂O, 8CdCl₂·YCl₃·15H₂O was a kind of metastable compound only in ternary system, and it was changed into 4CdCl₂·YCl₃·13H₂O with time. Both 4∶1 type and 5∶2 type existed in ternary and quaternary system, but they were also congruently soluble compounds in quaternary system. They have been prepared from the system and have been characterized by XRD, TC-DTG and DSC.     

CsCl-TmCl3-HCl-H2O(25 ℃)的相平衡及其固相化合物

The equilibrium solubilities of the quaternary system CsCl-TmCl₃-HCl-H₂O was determined at 25 ℃ and the corresponding equilibrium diagram was constructed. The diagram is a complicated system with limited solid solutions and formation of a new compound 3CsCl·2TmCl₃·14H₂O. The new compound has been characterized by XRD, TC-DTG and fluorescence spectrometry. Results show that upconversion spectrum exhibits at 335 nm when exciting at 860 nm, and fluorescence spectrum exhibits at 295 nm and 385 nm when exciting at 240 nm. The compound loses its crystal water by four steps at 50 to 250 ℃. Using a heat conduction calorimeter, the standard molar enthalpy of dissolution of 3CsCl·2TmCl₃·14H₂O was determined to be (-11.601 ± 0.050) kJ·mol^-1 at 298.15 K.