The properties of wood can be improved through steam-heat treatment.There are many studies about mechanical properties of steam-heat treated wood,but very few studies are on the aspects of chemical modifications.In th...The properties of wood can be improved through steam-heat treatment.There are many studies about mechanical properties of steam-heat treated wood,but very few studies are on the aspects of chemical modifications.In this study,FT-IR spectra combined with SD-IR spectra,correlation coefficients and 2DIR spectra are employed to analyze the chemical modifications of teak[Tectona grandis L.F.） wood during steam-heat treatment under treatment temperatures from 120 ℃ to 220 ℃ at intervals of 20 ℃.Acetic acid,which is produced during steam-heat treatment,acts as a catalyst of condensation and degradation reactions of wood components.The changes of wood components are more and more intense with increasing the treatment temperature.The sensitivity of wood samples to thermal perturbation rises initially with increasing treatment temperature before falling back.The steam-heat treated wood under180℃ is the most sensitive.展开更多
A novel compound, （4,4＇-Hbpy）3[NaMo8O26]（4,4＇-bpy）2（H2O）4 1 （bpy=bipydine）, was synthesized by the hydrothermal method. Single-crystal X-ray diffraction shows that compound 1 belongs to the monoclinic system...A novel compound, （4,4＇-Hbpy）3[NaMo8O26]（4,4＇-bpy）2（H2O）4 1 （bpy=bipydine）, was synthesized by the hydrothermal method. Single-crystal X-ray diffraction shows that compound 1 belongs to the monoclinic system, space group C2/m with a=19.1921（5）, b=18.6931（6）, c=9.3821（3） A° β=104.8020（11）°, V=3254.22（17）A°^3 C50H51Mo8N10NaO30, Mr=2062.52, Z=2, F（000）=2016, μ=1.591 mm^-1 and Dc=2.105 g/cm^3. The final R=0.0283 and wR=0.0912 for 3118 observed reflections （I〉20（I））. Compound 1 contains the β-[Mo8O26]^4-anion, sodium ion, 4,4＇-bpy and lattice crystalline water molecules. The β-[MosO26] units link the sodium ion to form a chain structure. The infinitechains of [Na（Mo8O26）]^3- blocks are surrounded by protonized 4,4＇-bpy cations, 4,4＇-bpy and lattice crystalline water molecules. The 2D-IR correlation spectroscopy study indicates that the stretching vibrations of Mo=O occur more preferentially due to the thermal effect. The TGA analysis shows that compound 1 has high thermal stability.展开更多
A three-dimensional （3D） Keggin-type heteropolytungstate{Zn（phen）3}3[ZnW12O40]·9H2O 1 （phen = 1,10-phenanthroline） has been synthesized through a conventional hydrothermal synthesis and was characterized by...A three-dimensional （3D） Keggin-type heteropolytungstate{Zn（phen）3}3[ZnW12O40]·9H2O 1 （phen = 1,10-phenanthroline） has been synthesized through a conventional hydrothermal synthesis and was characterized by X-ray single-crystal diffraction analysis, X-ray powder diffraction （XRD）, IR, UV-DRS, thermogravimetric analysis （TGA）, thermal-dependent 2D-IR correlation spectroscopy （2D-COS IR） and Raman spectrum. Crystal data for compound 1： trigonal system, space group R3 with a = b = 25.268（4）, c = 17.462（5） A, ）, = 120°, V= 9655（4） A3 and Z = 3. Compound 1 is allomorphic to {Co（phen）3}3[CoW12O40]·9H2O 2, which has been reported by Feng Chai et al. In compound 2, its prominent feature is that the decisive role of water molecules （O-H…O） builds a 3D supramolecular structure. However, in the structure of compound 1, the interlayer space is filled by Zn（phen）3]2＋ cations which linked the layers via C-H…O hydrogen bonding interactions to construct a three-dimensional framework. Two compounds are different in weak interactions, so we identify them by Thermal-dependent 2D-COS IR. Moreover, the fluorescence of compound 1 was also described.展开更多
利用程序控温的水热合成法得到了两种含有2，2＇-bipy及[M003]簇骼的化合物：[（2，2＇-bipy）2（Mo03）3]。（工）和[（2，2＇-bipy）（M003）]n（11）。为了阐明这两个化合物结构与谱学的关系，通过XRD、FT-IR、热微扰2D-IR相关光谱...利用程序控温的水热合成法得到了两种含有2，2＇-bipy及[M003]簇骼的化合物：[（2，2＇-bipy）2（Mo03）3]。（工）和[（2，2＇-bipy）（M003）]n（11）。为了阐明这两个化合物结构与谱学的关系，通过XRD、FT-IR、热微扰2D-IR相关光谱、TG分析、SEM、高温红外分析、uV_visDRS光谱和固体荧光光谱研究手段进行研究，进而探讨结构与性能的关系。其XRD说明了化合物I和Ⅱ是纯物相；FTIR的特征振动频率和热微扰2D-IR相关光谱的响应峰与化合物I和Ⅱ的结构解析相一致，2D-IR的同步和异步相关光谱图还确定了化合物I和Ⅱ的钼氧簇骼振动强度随升温变化的先后顺序与高温红外解析相一致；通过TG分析和高温红外分析研究化合物I和Ⅱ的热稳定性；化合物I和Ⅱ的UV Vis DRS光谱显示在225～350 nm有宽的紫外吸收谱带；化合物I和Ⅱ的固体荧光光谱分别在277和295nm的激发下得到的最强发射峰值分别为460和480nm。本文阐明了化合物I和Ⅱ的配位情况，揭示了价电子在分子中相应能级间跃迁的内在规律；还验证了弱相互作用力在配合物的结构框架中不但起稳定作用，而且在耐热性扮演重要的角色。展开更多
A new compound {[Bi（trans-DAM）（cis-DAM）（H2O）]NO3·H2O}n 1 derived from bismuth and the flexible ligand N,N＇-diacetic acid imidazolium chloride （H2DAMCl） was obtained by hydrothermal synthesis and characte...A new compound {[Bi（trans-DAM）（cis-DAM）（H2O）]NO3·H2O}n 1 derived from bismuth and the flexible ligand N,N＇-diacetic acid imidazolium chloride （H2DAMCl） was obtained by hydrothermal synthesis and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic P21/c space group with a = 9.2298（18）, b = 13.339（3）, c = 17.090（3） , β = 105.38（2）°, V = 2028.7（7）A^3, Z = 4, C14H18N5O13Bi, Mr = 673.31, Dc = 2.204 g/cm^3, F（000） = 1296, μ = 8.772 mm-1, the final R = 0.0472 and wR = 0.1441 for 4129 observed reflections （I 〉 2σ（I））. In 1, the carboxylic groups from DAM- ligands adopt a cheating mode to link bismuth ions to form a 2D sheet network. These sheets are further connected by hydrogen bonding interactions to give an interesting 3D supramolecular framework. 2D correlation analysis of IR of 1 with thermal and magnetic perturbation was introduced to ascertain the characteristic adsorption of the groups overlapped in the 1D IR spectrum. Additionally, compound 1 exhibits fluorescent emission at room temperature.展开更多
基金sponsored by the National Natural Science Foundation of China(No.31270591)Province-Academy Cooperation Project of Zhejiang Province and Chinese Academy of Forestry(No.2013SY01)
文摘The properties of wood can be improved through steam-heat treatment.There are many studies about mechanical properties of steam-heat treated wood,but very few studies are on the aspects of chemical modifications.In this study,FT-IR spectra combined with SD-IR spectra,correlation coefficients and 2DIR spectra are employed to analyze the chemical modifications of teak[Tectona grandis L.F.） wood during steam-heat treatment under treatment temperatures from 120 ℃ to 220 ℃ at intervals of 20 ℃.Acetic acid,which is produced during steam-heat treatment,acts as a catalyst of condensation and degradation reactions of wood components.The changes of wood components are more and more intense with increasing the treatment temperature.The sensitivity of wood samples to thermal perturbation rises initially with increasing treatment temperature before falling back.The steam-heat treated wood under180℃ is the most sensitive.
基金This work was supported by the Foundation of Education Committee of Fujian Province (K02028, JB04049), the State Key Laboratory of Structural Chemistry, and Science and Technology Foundation of Fuzhou University
文摘A novel compound, （4,4＇-Hbpy）3[NaMo8O26]（4,4＇-bpy）2（H2O）4 1 （bpy=bipydine）, was synthesized by the hydrothermal method. Single-crystal X-ray diffraction shows that compound 1 belongs to the monoclinic system, space group C2/m with a=19.1921（5）, b=18.6931（6）, c=9.3821（3） A° β=104.8020（11）°, V=3254.22（17）A°^3 C50H51Mo8N10NaO30, Mr=2062.52, Z=2, F（000）=2016, μ=1.591 mm^-1 and Dc=2.105 g/cm^3. The final R=0.0283 and wR=0.0912 for 3118 observed reflections （I〉20（I））. Compound 1 contains the β-[Mo8O26]^4-anion, sodium ion, 4,4＇-bpy and lattice crystalline water molecules. The β-[MosO26] units link the sodium ion to form a chain structure. The infinitechains of [Na（Mo8O26）]^3- blocks are surrounded by protonized 4,4＇-bpy cations, 4,4＇-bpy and lattice crystalline water molecules. The 2D-IR correlation spectroscopy study indicates that the stretching vibrations of Mo=O occur more preferentially due to the thermal effect. The TGA analysis shows that compound 1 has high thermal stability.
基金This work is by the National Natural Science Foundation of China(No.22203006,No.21927901,No.92261206,No.21627805,No.12174012,No.21673004,No.21821004,No.21674001,and No.21790363)Ministry of Science and Technology of China(a special talent program)and the Beijing City.
基金supported by the NNSFC(No.21473030,1371033)Fujian Provincial Natural Science Foundation(2013J01042)the Open Fund of State Key Laboratory of Structural Chemistry(20130015)
文摘A three-dimensional （3D） Keggin-type heteropolytungstate{Zn（phen）3}3[ZnW12O40]·9H2O 1 （phen = 1,10-phenanthroline） has been synthesized through a conventional hydrothermal synthesis and was characterized by X-ray single-crystal diffraction analysis, X-ray powder diffraction （XRD）, IR, UV-DRS, thermogravimetric analysis （TGA）, thermal-dependent 2D-IR correlation spectroscopy （2D-COS IR） and Raman spectrum. Crystal data for compound 1： trigonal system, space group R3 with a = b = 25.268（4）, c = 17.462（5） A, ）, = 120°, V= 9655（4） A3 and Z = 3. Compound 1 is allomorphic to {Co（phen）3}3[CoW12O40]·9H2O 2, which has been reported by Feng Chai et al. In compound 2, its prominent feature is that the decisive role of water molecules （O-H…O） builds a 3D supramolecular structure. However, in the structure of compound 1, the interlayer space is filled by Zn（phen）3]2＋ cations which linked the layers via C-H…O hydrogen bonding interactions to construct a three-dimensional framework. Two compounds are different in weak interactions, so we identify them by Thermal-dependent 2D-COS IR. Moreover, the fluorescence of compound 1 was also described.
文摘利用程序控温的水热合成法得到了两种含有2，2＇-bipy及[M003]簇骼的化合物：[（2，2＇-bipy）2（Mo03）3]。（工）和[（2，2＇-bipy）（M003）]n（11）。为了阐明这两个化合物结构与谱学的关系，通过XRD、FT-IR、热微扰2D-IR相关光谱、TG分析、SEM、高温红外分析、uV_visDRS光谱和固体荧光光谱研究手段进行研究，进而探讨结构与性能的关系。其XRD说明了化合物I和Ⅱ是纯物相；FTIR的特征振动频率和热微扰2D-IR相关光谱的响应峰与化合物I和Ⅱ的结构解析相一致，2D-IR的同步和异步相关光谱图还确定了化合物I和Ⅱ的钼氧簇骼振动强度随升温变化的先后顺序与高温红外解析相一致；通过TG分析和高温红外分析研究化合物I和Ⅱ的热稳定性；化合物I和Ⅱ的UV Vis DRS光谱显示在225～350 nm有宽的紫外吸收谱带；化合物I和Ⅱ的固体荧光光谱分别在277和295nm的激发下得到的最强发射峰值分别为460和480nm。本文阐明了化合物I和Ⅱ的配位情况，揭示了价电子在分子中相应能级间跃迁的内在规律；还验证了弱相互作用力在配合物的结构框架中不但起稳定作用，而且在耐热性扮演重要的角色。
基金supported by the National Natural Science Foundation of China (No. 20873021)the State Key Laboratory of Structure Chemistry and the Young Talent Programmed of Fujian Province (No. 2006F3072)
文摘A new compound {[Bi（trans-DAM）（cis-DAM）（H2O）]NO3·H2O}n 1 derived from bismuth and the flexible ligand N,N＇-diacetic acid imidazolium chloride （H2DAMCl） was obtained by hydrothermal synthesis and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic P21/c space group with a = 9.2298（18）, b = 13.339（3）, c = 17.090（3） , β = 105.38（2）°, V = 2028.7（7）A^3, Z = 4, C14H18N5O13Bi, Mr = 673.31, Dc = 2.204 g/cm^3, F（000） = 1296, μ = 8.772 mm-1, the final R = 0.0472 and wR = 0.1441 for 4129 observed reflections （I 〉 2σ（I））. In 1, the carboxylic groups from DAM- ligands adopt a cheating mode to link bismuth ions to form a 2D sheet network. These sheets are further connected by hydrogen bonding interactions to give an interesting 3D supramolecular framework. 2D correlation analysis of IR of 1 with thermal and magnetic perturbation was introduced to ascertain the characteristic adsorption of the groups overlapped in the 1D IR spectrum. Additionally, compound 1 exhibits fluorescent emission at room temperature.
