Cyclotetrabenzoin: Facile Synthesis of a Shape‐Persistent Molecular Square and Its Assembly into Hydrogen‐Bonded Nanotubes

Cyanide‐catalyzed benzoin condensation of terephthaldehyde produces a cyclic tetramer, which we propose to name cyclotetrabenzoin. Cyclotetrabenzoin is a square‐shaped macrocycle ornamented with four α‐hydroxyketone functionalities pointing away from the central cavity, the dimensions of which are 6.9×6.9 Å. In the solid state, these functional groups extensively hydrogen bond, resulting in a microporous three‐dimensional organic framework with one‐dimensional nanotube channels. This material exhibits permanent—albeit low‐porosity, with a Langmuir surface area of 52 m² g^?1. Cyclotetrabenzoin’s easy and inexpensive synthesis and purification may inspire the creation of other shape‐persistent macrocycles and porous molecular crystals by benzoin condensation.     

Role of oxygen in generation of active radicals in the initiating system benzoin ether-n,n′-tetramethyl-<Emphasis Type="Italic">p</Emphasis>-phenylenediamine

Using EPR, we have observed the initiating effect of oxygen on generation of active radicals in the donor-acceptor pair benzoin ether - N,N-tetramethyl-p-phenylenediamine under photostimulation.__________Translated from Teoreticheskaya i Éksperimentalnaya Khimiya, Vol. 41, No. 1, pp. 60–62, January–February, 2005.     

含硫席夫碱安息香缩肼基二硫代甲酸甲酯过渡金属配合物的合成与表征

合成和表征了新的含硫席夫碱—安息香缩肼基二硫代甲酸甲酯 (H2 L)及与Mn(Ⅱ ) ,Co(Ⅱ ) ,Ni(Ⅱ )Zn(Ⅱ )和Cd(Ⅱ )生成的配合物 [M(HL) 2 ]。结果表明这些配合物中安息香缩肼基二硫代甲酸甲酯存在为去质子化的烯硫醇式三齿配体 ,通过甲亚胺基氮原子、醇羟基氧原子和烯硫醇硫原子配位 ,金属离子处于六配位的八面体环境。     

键合型纤维素—苯基氨基甲酸酯手性固定相的制备及用于对映异构？…

采用化学键合法,利用４,４′－二苯基甲基二异氰酸酯作间隔臂,通过纤维素葡萄糖单元上２、３或６－位上的羟基将纤维素衍生物键合在氨丙基硅胶上,制备了键合型纤维素－苯基氨基甲酸酯手性固定相。同时,以微晶纤维素和苯基异氰酸酯为原料,合成了纤维素－三苯基氨基甲酸酯,并以未修饰的硅胶为载体,制备了涂敷型纤维素－三苯基氨基甲酸酯手性固定相。分别对键合型和涂敷型两类手性固定相进行了表征,并首次在纤维素－苯基氨基甲     

手性固定相Chirex 3001对安息香和联萘酚及其类似物的分子识别

利用分子力学方法, 建立了苯基甘氨酸型手性固定相Chirex 3001的简化模型, 并探讨了手性固定相Chirex 3001与安息香和联萘酚及其类似物的识别机制. 模拟结果表明, 固定相主体与手性客体分子识别作用的推动力主要来自于它们之间的π-π堆积、氢键和范德华等作用. 主体与(S)-构型的客体1～3结合能力强于(R)-构型的客体, 而对于客体4～6, 则是与(R)-构型的结合强于(S)-构型, 这与高效液相色谱拆分实验结果相符. 客体1～3对映体在Chirex 3001柱上的分离因子分别为1.02, 1.04和1.11, (R)-构型先被洗脱; 客体4～6对映体的分离因子分别为1.23, 1.26和1.09, (S)-构型先被洗脱.     

A new way to synthesize benzoin isopropyl ether on Cu-Fe-hydrotalcite

An efficient synthesis of benzoin isopropyl ether with benzaldehyde and propanol in the presence of heterogeneous recyclable Cu-Fe-hydrotalcite catalyst has been explored. Cu-Fe-hydrotalcite was firstly successfully synthesized over Jahn-Teller effect of Cu2+. The catalytic test result showed that Cu-Fe-hydrotalcite could be used as a good catalyst in the synthesis of benzoin isopropyl ether. The highest conversion of benzaldehyde was 59.7% and the selectivity of benzoin isopropyl ether was nearly 100%. By ...     

Direct Electrochemical Synthesis and Crystal Structure of a New Mononuclear Copper(Ⅱ) Complex: [(bipy)2Cu(PhCOO)]ClO4·(benzil) (benzil = 1,2-Diphenyl-ethane-1,2-dione)

A new mononuclear copper(Ⅱ) complex [(bipy)2Cu(PhCOO)]ClO4·(benzil) (bipy=2,2'-bipyridine, benzil=1,2-diphenyl-ethane-1,2-dione) was synthesized by direct electrochemical oxidation of Cu electrode in an acetonitrile solution with benzoic acid, 2,2'-bipyridine and benzoin. As soon as the current flowed in the cell, benzoin was oxidized to benzil quickly. The crystal structure was determined by X-ray diffraction. It belongs to monoclinic system, space group P21/c with a=14.860(2), b=20.784(3), c=11.9150(17) (A), β=101.401(3)°, V=3607.3(9) (A)3, Z=4, Mr=806.69, Dc=1.485 g/cm3, F(000)=1660, μ=0.742 mm-1, R=0.0788 and wR=0.1519 for 6254 observed reflections (Ⅰ ＞ 2σ(Ⅰ)). The complex contains a mononuclear [(bipy)2Cu(PhCOO)] cation, a solvate benzil molecule and a ClO4- anion which locates around the cation outside acting as the counter ion. The Cu(Ⅱ) ion is coordinated by two 2,2'-bipyridines and one benzoato ligand to form a distorted square-pyramid.