Infrared spectroscopy studies of 2-methyl-4,5-dirnethoxy-3-oxo-2H-pyridlzine (MDOP) in 12 pure organic solvents were undertaken to investigate the solvent-solute interactions. The frequencies of the carbonyl (C = O) o...Infrared spectroscopy studies of 2-methyl-4,5-dirnethoxy-3-oxo-2H-pyridlzine (MDOP) in 12 pure organic solvents were undertaken to investigate the solvent-solute interactions. The frequencies of the carbonyl (C = O) of MDOP were correlated with solvent properties such as solvent acceptor number (AN) and the linear solvation energy relationships (LSER). These frequencies showed a good correlation with the solvent acceptor number (AN) and the LSER.展开更多
This research on the solvent effects of 2-methyl-4,5-dimethoxy-3-oxo-2H-pyridizine(MDOP) in binary solvent systems on the infrared spectra for MDOP in n-hexane/CHCl3 mixture solvents showed that there were three forms...This research on the solvent effects of 2-methyl-4,5-dimethoxy-3-oxo-2H-pyridizine(MDOP) in binary solvent systems on the infrared spectra for MDOP in n-hexane/CHCl3 mixture solvents showed that there were three forms of carbonyl stretching vibration band[v(C=O)] of MPOP as mole fraction of CHCl3 in the binary solvents changes.In pure n-hexane solvent,the v(C=O) of MODP appeared at a relatively high wavenumber.With CHCl3 added,the v(C=O) shifted to lower wavenumbers.Two new bands were observed over a certain range of mixture solvent compositions.The origin of the bands was discussed in the terms of two kinds of hydrogen bond together with their individual dependence on mixture composition.COmparisons were drawn for the solvent sensitivities of v(C=O) for propanone.展开更多
In the previous paper(Ⅲ), the following equation of solvent effect in organic chemistry was suggested:Where Ei is a physical or chemical property of the substrate in the solvent i and E0 is that in n-hexane. Ai and D...In the previous paper(Ⅲ), the following equation of solvent effect in organic chemistry was suggested:Where Ei is a physical or chemical property of the substrate in the solvent i and E0 is that in n-hexane. Ai and Di are constants of electron acception and donation effect of the solvent i respectively. VAi and VDi are constants of electron acception and donation space effect of the solvent i respectively, a and d are the sensitivities of E of the substrate vs the change of Ai and Di. Va and Vd are the constants of electron acception and donation space effect of the substrate respectively. In IR spectra E couJd be substituted by the wavenumber (v). Ai and VAi have been estalished for 18 organic solvents (n-C6H14, n-C7H16, cyclohexane, CC14, Ph-Me, ClCH:CCl2, Et2O, CHCl3, C6H6, CH2Cl2,ClCH2 CH2Cl, Ph-NO2, THF, 1,4-dioxane, Et-NO2. MeCO2Et, Me-NO2, Me-CN).In this paper Di and VDi have been established for these solvents. The equation also has been tested by the vC-X (X=Cl, Br) of five alkylhalides (t-BuCl, ) n-C5H11Cl,t-BuBr, Et-Br, EtC(H)BrMe) and YC=O of three carboxyl compounds (t-BuCOMe,Me2CO, MHB) and seven organotin compounds [(Ph2MeSiCH2)3SnO2C-C6H4-X-p (X=H-, CH3-, CH3O-, NO2-, F-, Cl-, I-)].The relationship (u = ρ·σ + vo) between vC=O of organotin compounds and Hammett constants (σ) of the substituted groups in different solvents was studied and a relationship bewteen ρ and Ai, VAi ) Di, VDi of the slovents was found.展开更多
文摘Infrared spectroscopy studies of 2-methyl-4,5-dirnethoxy-3-oxo-2H-pyridlzine (MDOP) in 12 pure organic solvents were undertaken to investigate the solvent-solute interactions. The frequencies of the carbonyl (C = O) of MDOP were correlated with solvent properties such as solvent acceptor number (AN) and the linear solvation energy relationships (LSER). These frequencies showed a good correlation with the solvent acceptor number (AN) and the LSER.
文摘This research on the solvent effects of 2-methyl-4,5-dimethoxy-3-oxo-2H-pyridizine(MDOP) in binary solvent systems on the infrared spectra for MDOP in n-hexane/CHCl3 mixture solvents showed that there were three forms of carbonyl stretching vibration band[v(C=O)] of MPOP as mole fraction of CHCl3 in the binary solvents changes.In pure n-hexane solvent,the v(C=O) of MODP appeared at a relatively high wavenumber.With CHCl3 added,the v(C=O) shifted to lower wavenumbers.Two new bands were observed over a certain range of mixture solvent compositions.The origin of the bands was discussed in the terms of two kinds of hydrogen bond together with their individual dependence on mixture composition.COmparisons were drawn for the solvent sensitivities of v(C=O) for propanone.
文摘In the previous paper(Ⅲ), the following equation of solvent effect in organic chemistry was suggested:Where Ei is a physical or chemical property of the substrate in the solvent i and E0 is that in n-hexane. Ai and Di are constants of electron acception and donation effect of the solvent i respectively. VAi and VDi are constants of electron acception and donation space effect of the solvent i respectively, a and d are the sensitivities of E of the substrate vs the change of Ai and Di. Va and Vd are the constants of electron acception and donation space effect of the substrate respectively. In IR spectra E couJd be substituted by the wavenumber (v). Ai and VAi have been estalished for 18 organic solvents (n-C6H14, n-C7H16, cyclohexane, CC14, Ph-Me, ClCH:CCl2, Et2O, CHCl3, C6H6, CH2Cl2,ClCH2 CH2Cl, Ph-NO2, THF, 1,4-dioxane, Et-NO2. MeCO2Et, Me-NO2, Me-CN).In this paper Di and VDi have been established for these solvents. The equation also has been tested by the vC-X (X=Cl, Br) of five alkylhalides (t-BuCl, ) n-C5H11Cl,t-BuBr, Et-Br, EtC(H)BrMe) and YC=O of three carboxyl compounds (t-BuCOMe,Me2CO, MHB) and seven organotin compounds [(Ph2MeSiCH2)3SnO2C-C6H4-X-p (X=H-, CH3-, CH3O-, NO2-, F-, Cl-, I-)].The relationship (u = ρ·σ + vo) between vC=O of organotin compounds and Hammett constants (σ) of the substituted groups in different solvents was studied and a relationship bewteen ρ and Ai, VAi ) Di, VDi of the slovents was found.
文摘目的：研究长白山地区狼爪瓦松（Orostachys cartilaginea）、钝叶瓦松（Orostachys malacophyllus）和库页红景天（Rhodiola sachalinensis）的红外光谱鉴别。方法：分别用石油醚、乙酸乙酯、甲醇进行提取,归纳不同溶剂提取物的红外光谱特征,结合SPSS（Statistical Product and Service Solutions）软件对红外谱图对比分析。结果：狼爪瓦松、钝叶瓦松的提取物的红外光谱中存在共有峰和差异性,狼爪瓦松、钝叶瓦松甲醇提取物的红外光谱可以对狼爪瓦松、钝叶瓦松进行区分。结论：该方法快速、简便、特征性强,为景天科植物的药用植物质量评价提供依据。
