The structures of several recently reported organometallic NLO chromophores, (thio-phene) manganese tricarbonyl cations, were fully optimized at the DFT non-local (GGA) level. The calculated results show that the fra...The structures of several recently reported organometallic NLO chromophores, (thio-phene) manganese tricarbonyl cations, were fully optimized at the DFT non-local (GGA) level. The calculated results show that the fragments 2-SC4H3CH=CHC6H4-R in these organometallic chromophores are not planar with dihedral angles of 42.2~59.8 between two aromatic rings, which are different from those of uncoordinated counterparts. Based on the DFT geometry opti-mization, the second-order nonlinear optical polarizabilities were calculated by using RPA method. The calculated results indicate that incorporation of +3Mn(CO) unit with thiophene leads to a sub-stantial increase in the second-order polarizability (b).展开更多
Polychlorinated dibenzothiophenes（PCDTs） are classified as persistent organic pollutants in the environment,so the analysis of PCDTs by their gas chromatographic behaviors is of great significance.Quantitative struc...Polychlorinated dibenzothiophenes（PCDTs） are classified as persistent organic pollutants in the environment,so the analysis of PCDTs by their gas chromatographic behaviors is of great significance.Quantitative structure-retention relationship（QSRR） analysis is a useful technique capable of relating chromatographic retention time to the molecular structure.In this paper,a QSRR study of 37 PCDTs was carried out by using molecular electronegativity distance vector（MEDV） descriptors and multiple linear regression（MLR） and partial least-squares regression（PLS） methods.The correlation coefficient R of established MLR,PLS models,leave-one-out（LOO） cross-validation（CV）,Q2ext were 0.9951,0.9942,0.9839（MLR） and 0.9925,0.9915,0.9833（PLS）,respectively.Results showed that the model exhibited excellent estimate capability for internal sample set and good predictive capability for external sample set.By using MEDV descriptors,the QSRR model can provide a simple and rapid way to predict the gas-chromatographic retention indices of polychlorinated dibenzothiophenes in conditions of lacking standard samples or poor experimental conditions.展开更多
The title compound 2, 3-diethoxycarbonyl-4-phenyl-5-morpholinylthiophene (C20H23NO5S, Mr=389. 47) was obtained by the reaction of a-thiobenzoylth-ioformmorpholine with diethyl acetylene dicarboxylate - The crystal is ...The title compound 2, 3-diethoxycarbonyl-4-phenyl-5-morpholinylthiophene (C20H23NO5S, Mr=389. 47) was obtained by the reaction of a-thiobenzoylth-ioformmorpholine with diethyl acetylene dicarboxylate - The crystal is prismatic, spacegroup P1 ( 2), with unit cell constants 2337 observed reflections . X-ray analysis reveals that interatomic dis-tances for C(1 ) -C(2) and C(3) -C (4) are 1. 393 (4), 1. 370 (4) , respectively,which show that they are C=C double bond. The atoms of C(1 ), C(2), C(3), C(4)and S form a thiophene ring. The dihedral ang1es between thiophene ring and C(5) -C(6) -C(7) -C(8) plane, phenyl ring are 31. 42 and 43. 78, respectively. The mor-pholine ring adopts chair conformation.展开更多
A series of model polymerization are carried out via the one-pot externally initiated Kumada catalyst-transfer polycondensation （KCTP） of 2-bromo-5-chloromagne- slum thiophene monomers, and the excess amount of init...A series of model polymerization are carried out via the one-pot externally initiated Kumada catalyst-transfer polycondensation （KCTP） of 2-bromo-5-chloromagne- slum thiophene monomers, and the excess amount of initiators or catalysts are found no need to be isolated during the polycondensation process. Especially, the impacts of the nickel catalyst loading variation on regioregularity （rr）, yield, molecular weight （Mn）, polydispersity （PDI） and initiation efficiency of poly（3-hexylthiophene） （P3HT） are systematically investigated. The IH NMR, size-exclusion chromatography （SEC）, and MALDI-TOF mass spectroscopy results indicated that an excess amount of catalyst does not influence yield, rr, Mn, and PDI of P3HT, nor the initiation efficiency. However, the PDI of the product is broad, and the Mn and rr values decreased in the absence of 1,3-bis （diphenylphosphino）propane （dppp）. It can be concluded that the in-situ KCTP polymerization of P3HT is a practical and effective process. These results are especially valuable for the synthesis of all-conjugated block copolymers where macroinitiators are used.展开更多
以2,5-二羧酸-3,4-乙撑二氧噻吩为原料,首次采用CuY型分子筛作催化剂应用于3,4-乙撑二氧噻吩合成,反应温度有了明显降低,合成条件更温和,产品收率更高。通过实验探讨了催化剂、温度、溶剂等因素对反应的影响。结果表明:当采用CuY型分子...以2,5-二羧酸-3,4-乙撑二氧噻吩为原料,首次采用CuY型分子筛作催化剂应用于3,4-乙撑二氧噻吩合成,反应温度有了明显降低,合成条件更温和,产品收率更高。通过实验探讨了催化剂、温度、溶剂等因素对反应的影响。结果表明:当采用CuY型分子筛为催化剂、二甲基亚砜为溶剂、反应温度为135℃时,收率最高。产品结构经1 H NMR、13C NMR、IR和元素分析进行了表征。展开更多
文摘The structures of several recently reported organometallic NLO chromophores, (thio-phene) manganese tricarbonyl cations, were fully optimized at the DFT non-local (GGA) level. The calculated results show that the fragments 2-SC4H3CH=CHC6H4-R in these organometallic chromophores are not planar with dihedral angles of 42.2~59.8 between two aromatic rings, which are different from those of uncoordinated counterparts. Based on the DFT geometry opti-mization, the second-order nonlinear optical polarizabilities were calculated by using RPA method. The calculated results indicate that incorporation of +3Mn(CO) unit with thiophene leads to a sub-stantial increase in the second-order polarizability (b).
基金supported by the Foundation of Returned Scholars (Main Program) of Shanxi Province (200902)
文摘Polychlorinated dibenzothiophenes（PCDTs） are classified as persistent organic pollutants in the environment,so the analysis of PCDTs by their gas chromatographic behaviors is of great significance.Quantitative structure-retention relationship（QSRR） analysis is a useful technique capable of relating chromatographic retention time to the molecular structure.In this paper,a QSRR study of 37 PCDTs was carried out by using molecular electronegativity distance vector（MEDV） descriptors and multiple linear regression（MLR） and partial least-squares regression（PLS） methods.The correlation coefficient R of established MLR,PLS models,leave-one-out（LOO） cross-validation（CV）,Q2ext were 0.9951,0.9942,0.9839（MLR） and 0.9925,0.9915,0.9833（PLS）,respectively.Results showed that the model exhibited excellent estimate capability for internal sample set and good predictive capability for external sample set.By using MEDV descriptors,the QSRR model can provide a simple and rapid way to predict the gas-chromatographic retention indices of polychlorinated dibenzothiophenes in conditions of lacking standard samples or poor experimental conditions.
文摘The title compound 2, 3-diethoxycarbonyl-4-phenyl-5-morpholinylthiophene (C20H23NO5S, Mr=389. 47) was obtained by the reaction of a-thiobenzoylth-ioformmorpholine with diethyl acetylene dicarboxylate - The crystal is prismatic, spacegroup P1 ( 2), with unit cell constants 2337 observed reflections . X-ray analysis reveals that interatomic dis-tances for C(1 ) -C(2) and C(3) -C (4) are 1. 393 (4), 1. 370 (4) , respectively,which show that they are C=C double bond. The atoms of C(1 ), C(2), C(3), C(4)and S form a thiophene ring. The dihedral ang1es between thiophene ring and C(5) -C(6) -C(7) -C(8) plane, phenyl ring are 31. 42 and 43. 78, respectively. The mor-pholine ring adopts chair conformation.
文摘A series of model polymerization are carried out via the one-pot externally initiated Kumada catalyst-transfer polycondensation （KCTP） of 2-bromo-5-chloromagne- slum thiophene monomers, and the excess amount of initiators or catalysts are found no need to be isolated during the polycondensation process. Especially, the impacts of the nickel catalyst loading variation on regioregularity （rr）, yield, molecular weight （Mn）, polydispersity （PDI） and initiation efficiency of poly（3-hexylthiophene） （P3HT） are systematically investigated. The IH NMR, size-exclusion chromatography （SEC）, and MALDI-TOF mass spectroscopy results indicated that an excess amount of catalyst does not influence yield, rr, Mn, and PDI of P3HT, nor the initiation efficiency. However, the PDI of the product is broad, and the Mn and rr values decreased in the absence of 1,3-bis （diphenylphosphino）propane （dppp）. It can be concluded that the in-situ KCTP polymerization of P3HT is a practical and effective process. These results are especially valuable for the synthesis of all-conjugated block copolymers where macroinitiators are used.
文摘以2,5-二羧酸-3,4-乙撑二氧噻吩为原料,首次采用CuY型分子筛作催化剂应用于3,4-乙撑二氧噻吩合成,反应温度有了明显降低,合成条件更温和,产品收率更高。通过实验探讨了催化剂、温度、溶剂等因素对反应的影响。结果表明:当采用CuY型分子筛为催化剂、二甲基亚砜为溶剂、反应温度为135℃时,收率最高。产品结构经1 H NMR、13C NMR、IR和元素分析进行了表征。
