Synthesis of a new series of chiral Schiff's bases and their copper complexes

A new series of chiral Schiff's bases containing 2-hydroxybenzilideneaniline moieties and their copper complexes were synthesized and studied by differential scanning calorimetry, polarized optical microscopy, X-ray diffraction and EPR measurement. The results show that most of the Schiff's bases and only two of the copper complexes exhibited chiral smectic liquid crystal phases.

乙基苯基二氯化锡与2－羟基萘醛缩对甲氧基苯胺Schiff碱1∶1配合物的合成和晶体结构

乙基苯基二氯化锡与２－羟基萘醛缩对甲氧基苯胺Ｓｃｈｉｆｆ碱１∶１配合物的合成和晶体结构刘宝殿，包明，孙振刚，贺庆林，邢彦，贾恒庆，林永华（东北师范大学化学系，长春，１３００２４）（中国科学院长春应用化学研究所，长春）关键词乙基苯基二氯化锡，Ｓｃｈｉｆ...

β－烷氧羰乙基三氯化锡与2－羟基苯乙酮缩苯胺类Schiff碱配合物的合成与结构

合成并表征了１６种新的β－烷氧羰乙基三氯化锡与２－羟基苯乙酮缩苯胺类Ｓｃｈｉｆｆ碱配合物。测定了β－甲氧羰乙基三氯化锡与２－羟基苯乙酮缩对甲苯胺Ｓｃｈｉｆｆ碱配合物的晶体结构。晶体属于Ｐ空间群，晶胞参数：ａ＝１．０２０１（６）ｎｍ，ｂ＝１．０８２２（４）ｎｍ，ｃ＝１．３９４９（６）ｎｍ，ａ＝９９．８８（３）°，β＝９８．６３（４）°，γ＝９７．８６（４）°，Ｚ＝２。配合物是配体通过酚羟基氧原子与锡原子配键生成的，分子内存在羰基氧原子与锡原子的配键，锡原子的配位数是６。

SYNTHESIS AND PHASE-BEHAVIOR STUDIES OF 2 NEW CHIRAL LIQUID-CRYSTALS OF SCHIFF-BASE - THE INFLUENCE OF INTRAMOLECULAR HYDROGEN-BOND ON THE PHASE-BEHAVIOR

Two new chiral liquid crystals of schiff-base type have been synthesized. This series of compounds contain a-chloro acidic ester chain prepared from commercially available L-valine. Both of the compounds exhibit tilted smectic phases; their phase transitions were studied using DSC and polarized optical microscopy; the influence of intramolecular hydrogen bonds on the phase behavior was studied as well.

SYNTHESIS OF A NEW CHIRAL LIQUID-CRYSTAL WITH SCHIFF-BASE GROUP AND INVESTIGATION OF TEMPERATURE-DEPENDING FTIR SPECTRA

A new chiral liquid crystal with Schiff base group has been prepared, The structure of liquid crystal was confirmed by elementary analyses and H-1 NMR. Its phase transition was investigated by polarized optical microscope, DSC and temperature-depending FTIR spectra. The results showed that the chiral Schiff base showed monotropic phases behavior in certain temperature range, the phase sequence is I-N-*-S-B-S-G-K on the cooling sequence.

新的手性Schiff碱液晶的合成及变温红外光谱研究（Ⅰ）

合成了１个新的手性Ｓｃｈｉｆｆ碱类液晶并以ＤＳＣ、偏光显微镜及变温红外光谱等手段对其热致相变过程进行了研究。

稀土冠醚配合物的研究XX．Schiff碱型双冠醚N，N’－对苯二甲亚基双（4’－氨基苯并－15－冠－5）稀土配合物的合成和性质

合成了一种Ｓｃｈｉｆｆ碱型双冠醚Ｎ，Ｎ’－对苯二甲亚基双（４’－氨基苯并－１５－冠－５）及其稀土硝酸盐的固体配合物，通过元素分析、摩尔电导、ＩＲ、ＵＶ、１ＨＮＭＲ和热分析等对其性质作了表征与比较。

The synthesis and antioxidant activity of the Schiff bases of chitosan and carboxymethyl chitosan

Five kinds of Schiff bases of chitosan and carboxymethyl chitosan (CMCTS) have been prepared according to a previous method and the antioxidant activity was studied using an established system, such as superoxide and hydroxyl radical scavenging. Obvious differences between the Schiff bases of chitosan and CMCTS were observed, which might be related to contents of the active hydroxyl and amino groups in the molecular chains. (c) 2005 Elsevier Ltd. All rights reserved.

Antifungal properties of Schiff bases of chitosan, N-substituted chitosan and quaternized chitosan

Schiff bases of chitosan, N-substituted chitosan, and quaternized chitosan were synthesized and their antifungal properties were analyzed against Botrytis cinerea Pers. (B. cinerea pers.) and Colletotrichum lagenarium (Pass) Ell.et halst (C. lagenarium (Pass) Ell.et halst) based on the method of D. Jasso de Rodriguez and co-workers. The results showed that quaternized chitosan had better inhibitory properties than chitosan, Schiff bases of chitosan, and N-substituted chitosan. (c) 2007 Elsevier Ltd. All rights reserved.

Aminic nitrogen-bearing polydentate Schiff base compounds as corrosion inhibitors for iron in acidic media: A quantum chemical calculation

Quantum chemical calculations based on DFT method were performed on three polydentate Schiff base compounds (PSCs) used as corrosion inhibitors for iron in acid media to determine the relationship between the molecular structure of PSC and inhibition efficiency. The structural parameters, such as the frontier molecular orbital energy HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), the charge distribution of the studied inhibitors, the absolute electronegativity (chi) values, and the fraction of electrons (Delta N) transfer from inhibitors to iron, were also calculated and correlated with inhibition efficiencies. The results showed that the inhibition efficiency of PSCs increased with the increase in E-HOMO and decrease in E-LUMO-E-HOMO; and the areas containing N atoms are most possible sites for bonding the metal iron surface by donating electrons to the metal. (C) 2007 Elsevier Ltd. All rights reserved.

Synthetic studies on optically active Schiff-base ligands derived from condensation of 2-hydroxyacetophenone and chiral diamines

Three optically active Schiff-base ligands have been prepared by condensation of 2-hydroxyacetophenone with (IR,2R)-(-)-1,2-diaminocyclohexane, (1S,2S)-(-)1,2-diphenylethylenediamine or R-(+)-2,2'-diamino-1,1'-binaphthalene, respectively. The products have been characterized by their IR, H-1- and C-13-NMR spectra.