The unperturbed dimension and temperature character of poly(dibenzyl itaconate)s (PDBzI) are studied by a revised rotational isomeric state (RIS) method. The improved formulas of the mean-square radius of gyration, de...The unperturbed dimension and temperature character of poly(dibenzyl itaconate)s (PDBzI) are studied by a revised rotational isomeric state (RIS) method. The improved formulas of the mean-square radius of gyration, deduced by the pseudo-stereochemical equilibrium approach, may be used to investigate the configurational-conformational properties of atactic polymers with large side groups [poly(itaconates) for instance]. The calculated results showed that poly(itaconates) have larger dimension of the molecule than other vinyl polymers. Comparison of the dimension between considering and without considering side groups showed that the effect of large side groups on the unperturbed dimension for short-chain polymers is more obvious than that of long-chain polymers and, if the dimension of side groups increases, the effect also increases. The dimension differences of PDBzI between short-chain and long-chain polymers are investigated by the relation of characteristic ratios and temperature coefficients with temperature. Moreover, the dependence between the temperature coefficients and the tacticity of chains shows that the temperature characters of the isotactic, syndiotactic and atactic PDBzI chains have remarkable difference.展开更多
The deprotection of 1,3-dibenzyl-5-（N,N-dimethylamino）-6-phenyl-ethyluracil I was investigated. A practical, regioselective N3 deprotection of compound I was performed with excellent yield using cyclohexene as a hyd...The deprotection of 1,3-dibenzyl-5-（N,N-dimethylamino）-6-phenyl-ethyluracil I was investigated. A practical, regioselective N3 deprotection of compound I was performed with excellent yield using cyclohexene as a hydrogen donor.展开更多
A new complex, {Bi(Ⅲ)[S2CN(CH2C6H5)2]3}2·2CH3CN, was synthesized and characterized by elemental analysis, IR, TG, 1H NMR and X-ray single-crystal diffraction. The complex crystallizes in the triclinic system, sp...A new complex, {Bi(Ⅲ)[S2CN(CH2C6H5)2]3}2·2CH3CN, was synthesized and characterized by elemental analysis, IR, TG, 1H NMR and X-ray single-crystal diffraction. The complex crystallizes in the triclinic system, space group P1, with a = 12.705(6), b = 13.430(6), c = 15.489(12) , α = 102.135(12), β = 99.649(12), γ = 111.521(9)°, Z = 1, V = 2315(2) A3, Dc = 1.531 g·cm-3, F(000) = 1068, μ = 4.116 mm-1, the final R = 0.0559, w R = 0.1069 and S =1.056. The coordinated geometry of Bi(Ⅲ) with six sulfur atoms from three ligands is a distorted pentagonal pyramidal configuration, and the structural system is formed by weak interactions of Bi···S between two molecules. The complex was valued for its antibacterial activity by agar-streak method. It was found that the complex is weakly active against three of the five tested bacterial organisms.展开更多
A new monomer, 3,9-diallyl-3, 9-dibenzyl-1, 5,7,11 - tetraoxa- spiro [5,5] undecane (6) was prepared by the reaction of 2- allyl- 2' - benzyl- propanediol - 1.3 with dibutyltin oxide, and then treated with CS_2. M...A new monomer, 3,9-diallyl-3, 9-dibenzyl-1, 5,7,11 - tetraoxa- spiro [5,5] undecane (6) was prepared by the reaction of 2- allyl- 2' - benzyl- propanediol - 1.3 with dibutyltin oxide, and then treated with CS_2. Monomer 4 could be initiated by cationic initiators to give a viscous polymer (white powder in the case of polymerization at 0℃). Upon the NMR and IR spectra of the obtained polymer, the components and their relative amount were estimated. The polymerization mechanism was discussed.展开更多
Dimethyltin dichloride-dibenzyl sulfoxide,（（CH3）2SnCl2·O=S（CH2C6H5）2）,crystallizes in the orthorhombic space group P212121 with a superstructure of dimensions a = 11.9290（1）,b = 19.50490（1）,c = 55.7390...Dimethyltin dichloride-dibenzyl sulfoxide,（（CH3）2SnCl2·O=S（CH2C6H5）2）,crystallizes in the orthorhombic space group P212121 with a superstructure of dimensions a = 11.9290（1）,b = 19.50490（1）,c = 55.7390（6） ; Z = 28. The geometry of the five-coordinated tin atom in each of the seven independent adduct molecules is a square pyramid that is displaced towards a cis-trigonal bipyramid; the extent of displacement along the Berry pseudorotation pathway ranges from 20 to 45%.展开更多
基金Project supported by the National Basic Research Program (973) of China (No. 10574109)the Zhejiang Provincial Science and Technology Department (No. 2005C24008)the Natural Science Foundation of Zhejiang Province (No. Y604064), China
文摘The unperturbed dimension and temperature character of poly(dibenzyl itaconate)s (PDBzI) are studied by a revised rotational isomeric state (RIS) method. The improved formulas of the mean-square radius of gyration, deduced by the pseudo-stereochemical equilibrium approach, may be used to investigate the configurational-conformational properties of atactic polymers with large side groups [poly(itaconates) for instance]. The calculated results showed that poly(itaconates) have larger dimension of the molecule than other vinyl polymers. Comparison of the dimension between considering and without considering side groups showed that the effect of large side groups on the unperturbed dimension for short-chain polymers is more obvious than that of long-chain polymers and, if the dimension of side groups increases, the effect also increases. The dimension differences of PDBzI between short-chain and long-chain polymers are investigated by the relation of characteristic ratios and temperature coefficients with temperature. Moreover, the dependence between the temperature coefficients and the tacticity of chains shows that the temperature characters of the isotactic, syndiotactic and atactic PDBzI chains have remarkable difference.
基金Supported by the National Natural Science Foundation of China(No.20672008) "985" Program of the Ministry of Edu-cation of China
文摘The deprotection of 1,3-dibenzyl-5-（N,N-dimethylamino）-6-phenyl-ethyluracil I was investigated. A practical, regioselective N3 deprotection of compound I was performed with excellent yield using cyclohexene as a hydrogen donor.
基金supported by International Cooperation Project of the Science&Technology Agency of Henan Province(No.134300510013)
文摘A new complex, {Bi(Ⅲ)[S2CN(CH2C6H5)2]3}2·2CH3CN, was synthesized and characterized by elemental analysis, IR, TG, 1H NMR and X-ray single-crystal diffraction. The complex crystallizes in the triclinic system, space group P1, with a = 12.705(6), b = 13.430(6), c = 15.489(12) , α = 102.135(12), β = 99.649(12), γ = 111.521(9)°, Z = 1, V = 2315(2) A3, Dc = 1.531 g·cm-3, F(000) = 1068, μ = 4.116 mm-1, the final R = 0.0559, w R = 0.1069 and S =1.056. The coordinated geometry of Bi(Ⅲ) with six sulfur atoms from three ligands is a distorted pentagonal pyramidal configuration, and the structural system is formed by weak interactions of Bi···S between two molecules. The complex was valued for its antibacterial activity by agar-streak method. It was found that the complex is weakly active against three of the five tested bacterial organisms.
基金This project is supported by the National Natural Science Foundation of China
文摘A new monomer, 3,9-diallyl-3, 9-dibenzyl-1, 5,7,11 - tetraoxa- spiro [5,5] undecane (6) was prepared by the reaction of 2- allyl- 2' - benzyl- propanediol - 1.3 with dibutyltin oxide, and then treated with CS_2. Monomer 4 could be initiated by cationic initiators to give a viscous polymer (white powder in the case of polymerization at 0℃). Upon the NMR and IR spectra of the obtained polymer, the components and their relative amount were estimated. The polymerization mechanism was discussed.
文摘Dimethyltin dichloride-dibenzyl sulfoxide,（（CH3）2SnCl2·O=S（CH2C6H5）2）,crystallizes in the orthorhombic space group P212121 with a superstructure of dimensions a = 11.9290（1）,b = 19.50490（1）,c = 55.7390（6） ; Z = 28. The geometry of the five-coordinated tin atom in each of the seven independent adduct molecules is a square pyramid that is displaced towards a cis-trigonal bipyramid; the extent of displacement along the Berry pseudorotation pathway ranges from 20 to 45%.
