为研究格氏栲天然林凋落物的单宁含量,对凋落物单宁提取的最佳工艺进行探讨。采用香草醛法测定单宁含量,将乙醇作为提取溶剂,选择乙醇浓度、浸提温度与溶剂体积等因素进行单因素和L_9(3~3)正交试验。结果表明:在乙醇浓度70%,提取温度80...为研究格氏栲天然林凋落物的单宁含量,对凋落物单宁提取的最佳工艺进行探讨。采用香草醛法测定单宁含量,将乙醇作为提取溶剂,选择乙醇浓度、浸提温度与溶剂体积等因素进行单因素和L_9(3~3)正交试验。结果表明:在乙醇浓度70%,提取温度80℃,乙醇体积15 m L的条件下,单宁提取效果最佳,提取单宁含量为30.58 mg/g。展开更多
Solvothermal reaction of [WS4]2-with CuCN and trithiocyanuric acid（L1） in orga-nic solvents gave rise to a new W/Cu/S polymer with a 2D anionic network,namely [Et4N]2[WS4Cu3（C3N3S3H1.5）2]（1）.The anionic layer of...Solvothermal reaction of [WS4]2-with CuCN and trithiocyanuric acid（L1） in orga-nic solvents gave rise to a new W/Cu/S polymer with a 2D anionic network,namely [Et4N]2[WS4Cu3（C3N3S3H1.5）2]（1）.The anionic layer of 1 is constructed by the T-shaped {WS4Cu3} subunits as nodes and L1 as linkers and features a（4,4） topology.Both 1 and its isomorphous compound [Et4N]2[MoS4Cu3（C3N3S3H1.5）2]（2） have been fully characterized by X-ray crystal analysis,IR and microanalyses.Compounds 1 and 2 show optical transitions with band gaps of 2.17 and 1.84 eV,respectively.展开更多
A new compound [mpba][Cu_2Br_3]（1, mpba = 4-（N-methylpyridin-4-yl）benzoic acid） has been ionothermally synthesized and characterized by single-crystal X-ray diffraction analysis, infrared spectrum, elemental analy...A new compound [mpba][Cu_2Br_3]（1, mpba = 4-（N-methylpyridin-4-yl）benzoic acid） has been ionothermally synthesized and characterized by single-crystal X-ray diffraction analysis, infrared spectrum, elemental analyses, fluorescence spectrum, and thermogravimetric analysis. In compound 1, the [mpba]＋ cation is a new organic template, which is obtained firstly in this work by in situ alkylation reaction of N-heterocycles 4-（pyridin-4-yl）benzoic acid with [Emim]Br（Emim = 1-ethyl-3-methyl imidazolium）. Hirshfeld surface analysis shows that weak interactions between the [mpba]＋ cations and 1D inorganic [Cu_2Br_3]~– are mainly C–H···Br hydrogen bonds. In addition, a pairwise O–H···O interaction is observed between the adjacent [mpba]＋cations. These different types of weak interactions make compound 1 stable up to 300 ℃. Fluorescence spectrum investigation shows 1 has a strong yellow emission at 555 nm. Theoretical calculation not only demonstrates compound 1 is a wild band semiconductor with a 3.3 e V band gap but also elucidates the fluorescence emission derives from the p-π＊ transition of electrons from [Cu_2Br_3]~– to [mpba]~＋.展开更多
文摘为研究格氏栲天然林凋落物的单宁含量,对凋落物单宁提取的最佳工艺进行探讨。采用香草醛法测定单宁含量,将乙醇作为提取溶剂,选择乙醇浓度、浸提温度与溶剂体积等因素进行单因素和L_9(3~3)正交试验。结果表明:在乙醇浓度70%,提取温度80℃,乙醇体积15 m L的条件下,单宁提取效果最佳,提取单宁含量为30.58 mg/g。
基金supported by the State Key Laboratory of Structural Chemistry (CAS,SZD08002-2)National Basic Research Program of China (973 Program,2007CB815306)+2 种基金the National Natural Science Foundation of China (20903096,20733003)Young Scientist’s Foundation of Fujian Province (2006F3163)Knowledge Innovation Program of the Chinese Academy of Sciences
文摘Solvothermal reaction of [WS4]2-with CuCN and trithiocyanuric acid（L1） in orga-nic solvents gave rise to a new W/Cu/S polymer with a 2D anionic network,namely [Et4N]2[WS4Cu3（C3N3S3H1.5）2]（1）.The anionic layer of 1 is constructed by the T-shaped {WS4Cu3} subunits as nodes and L1 as linkers and features a（4,4） topology.Both 1 and its isomorphous compound [Et4N]2[MoS4Cu3（C3N3S3H1.5）2]（2） have been fully characterized by X-ray crystal analysis,IR and microanalyses.Compounds 1 and 2 show optical transitions with band gaps of 2.17 and 1.84 eV,respectively.
基金supported by the Natural Science Foundation of Fujian Province(No.2014J01029)
文摘A new compound [mpba][Cu_2Br_3]（1, mpba = 4-（N-methylpyridin-4-yl）benzoic acid） has been ionothermally synthesized and characterized by single-crystal X-ray diffraction analysis, infrared spectrum, elemental analyses, fluorescence spectrum, and thermogravimetric analysis. In compound 1, the [mpba]＋ cation is a new organic template, which is obtained firstly in this work by in situ alkylation reaction of N-heterocycles 4-（pyridin-4-yl）benzoic acid with [Emim]Br（Emim = 1-ethyl-3-methyl imidazolium）. Hirshfeld surface analysis shows that weak interactions between the [mpba]＋ cations and 1D inorganic [Cu_2Br_3]~– are mainly C–H···Br hydrogen bonds. In addition, a pairwise O–H···O interaction is observed between the adjacent [mpba]＋cations. These different types of weak interactions make compound 1 stable up to 300 ℃. Fluorescence spectrum investigation shows 1 has a strong yellow emission at 555 nm. Theoretical calculation not only demonstrates compound 1 is a wild band semiconductor with a 3.3 e V band gap but also elucidates the fluorescence emission derives from the p-π＊ transition of electrons from [Cu_2Br_3]~– to [mpba]~＋.
