新型电荷转移配合物的合成与表征

近年来有关多金属氧酸盐与有机化合物间电荷转移配合物的光化学和光致变色过程的研究日趋活跃［１,２］,但迄今这类电荷转移配合物中的多金属氧酸盐基本上为Ｌｉｎｄｑｕｉｓｔ结构的同多酸或Ｋｅｇｇｉｎ结构的杂多酸,有机给体则基本上限于有机胺及其衍生物（如酰胺）...     

Free-radical copolymerization of styrene with N-phenyl maleimide initiated by thiol

2-Methyl–2-undecanethiol was found efficient to initiate the free-radical copolymerization of styrene (St) with N-phenyl maleimide (NPMI) at 40°C. The initial copolymerization rate increases with the increasing of thiol concentration at first, then keeps constant with the further increasing of the thiol concentration. The charge-transfer complex (CTC) formed between St and NPMI was investigated in different solvents by using ¹H-NMR. There is no definite correlation between CTC equilibrium constant, K, and the polarity of the solvent. With the increasing of CTC concentration, both the copolymerization rate and NPMI content in copolymer enhances, indicating the participation of CTC in both initiation and propagation. The monomer reactivity ratios were calculated to be r_NPMI = 0.052 and r_St ? 0.166, showing an alternating tendency for the copolymerization of St with NPMI. The molecular weight approach has shown again the effect of CTC. The function of thiol as a regulator is mitigated due to the involvement of CTC. © 1992 John Wiley & Sons, Inc.     

Photoredox Chemistry of Polyoxometalates as a Photocatalyst

The photocatalytic action of polyoxometalates (PMs), which is initiated by the photoexcitation of the oxygen-to-metal charge-transfer (O M LMCT) bands of PM, is based on the electron–hole pair separation followed by reductive and oxidative reactions with surrounding molecules. It is shown that the O M LMCT triplet states are involved in the photoredox reactions in which the significance of the highly negative oxidation potential for the photoreduced PMs can be considered in connection with the photocatalytic H₂ formation from a great variety of organic substrates with their dehydrated oxidation. When the reaction of the photoreduced PMs with the electron acceptor hardly occurs kinetically or thermodynamically, they undergo self-assembled organization to nanosized supramolecules (as a result of photoencapsulation of small molecules and ring cluster formation). Some typical examples for the electron–hole pair separation and the photoredox reactions developed in our laboratory are discussed.     

31P CP-MAS NMR,Vibrational, and X-Ray Characterization of the Adducts of Triphenylphosphine Sulfide with ICl and IBr

The reactions between triphenylphosphine sulfide (Ph₃PS) and ICl in CCl₄ and IBr in CH₂Cl₂ in 1 : 1 molar ratio give the solid adducts Ph₃PS · ICl ( I ) and Ph₃PS · IBr ( II ) whose structures have been solved by X-ray diffraction. Compounds I and II consist of discrete molecule units and feature the S–I–Cl or S–I–Br linear group. The S–I bond distances in I , II (2.641(1), 2.665(1) Å respectively) and in compound 2 Ph₃PS · 3 I₂ ( III ) (2.729(2) Å) are correlable to the net increase in the I–X (X = Cl, Br, I) bond distance. The structural features of I , II and III are in accordance with ³¹P CP–MAS NMR, FT-Raman and FT-IR spectral data, and elucidate the nature of the donor (Ph₃PS)-acceptor (ICl, IBr, I₂) interaction.     

六次甲基四胺与HnXW12O40．mH2O(X=P,Si,Ge)电荷转移盐的合成、表征及非线性光学性质研究

合成了由六次甲基四胺与H     

SBN晶体中Eu~(3+)激发态~5D_0的无辐射跃迁

通过测量~5D_0→~7F_2发射带的荧光寿命与晶体温度的依赖关系,研究了Eu~(3+)激发态~5D_0的无辐射跃迁.结果表明,~5D_0→~7F_2带的温度淬灭效应主要是由于电荷转移态的最低能量太低,~5D_0态易被热激活至电荷转移,然后通过电荷转移无辐射弛豫至~7F_2态.     

TAAB四氮杂环铜配合物的合成,氧化还原及其TCNE复合盐的导电性质

ＴＡＡＢ四氮杂环铜配合物的合成、氧化还原及其ＴＣＮＥ复合盐的导电性质李明星，徐正，游效曾（南京大学配位化学研究所，配位化学国家重点实验室，南京，２１００９３）关键词ＴＡＡＢ大环，铜配合物，氧化还原性质，ＴＣＮＥ电荷转移盐，导电性质大环配合物的研究对于...     

奋乃静与甲酚红的荷移反应研究

采用光度法研究了电子给予体奋乃静与电子接受体甲酚红之间的荷移反应,据此建立了荷移光度法测定奋乃静含量的方法.实验表明,奋乃静与甲酚红在丙酮介质中,室温条件下即可形成稳定的1:2型荷移络合物,该络合物的最大吸收波长为434nm,表观摩尔吸光系数为1.19×10<'4>L·mol<'-1>·cm<'-1>.奋乃静的质量浓度...     

荷移光度法测定注射用头孢唑啉钠含量

以注射用头孢唑啉钠作为电荷给体,百里酚蓝作为电荷受体,用分光光度法研究了它们之间形成电荷转移配合物的条件。结果表明:在乙醇介质中,二者于室温即可形成1∶1的配合物,其最大吸收波长为450nm,4.67~93.32mg·L-1范围内呈线性关系,相关系数是0.9986,稳定常数是106.34,表观摩尔吸光系数ε=3.45×104L·mol-1·cm-1。对形成配合物的机理进行了探讨。应用拟订的方法对注射用头孢唑啉钠进行了含量测定,结果与文献方法一致,平均回收率为99.9%。