Pub Date : 2009-05-07DOI: 10.2174/1874846500902010011
Lung-Chien Chen, Ching-Ho Tien
This study presents a zinc oxide (ZnO) film deposited on a glass substrate by ultrasonic spraying pyrolysis. The ZnO nanostructure was formed by treating the as-deposited ZnO films with hydrogen. The root-mean-square (RMS) roughness increases from 5.83 nm to 12.53 nm during the treatment for 20 min, but slightly decreases to 11.87 nm at a treatment time of 30 min. In the range 400-500 nm, the transparency of all the films with hydrogen treatment is slightly lower than that of the untreated films. The slight drop in the transparency of the films with hydrogen treatment is caused by scattering from pin-holes or nanostructures on the surface.
{"title":"The Influence of Hydrogen Gas Treatment on the Characteristics of ZnO Films","authors":"Lung-Chien Chen, Ching-Ho Tien","doi":"10.2174/1874846500902010011","DOIUrl":"https://doi.org/10.2174/1874846500902010011","url":null,"abstract":"This study presents a zinc oxide (ZnO) film deposited on a glass substrate by ultrasonic spraying pyrolysis. The ZnO nanostructure was formed by treating the as-deposited ZnO films with hydrogen. The root-mean-square (RMS) roughness increases from 5.83 nm to 12.53 nm during the treatment for 20 min, but slightly decreases to 11.87 nm at a treatment time of 30 min. In the range 400-500 nm, the transparency of all the films with hydrogen treatment is slightly lower than that of the untreated films. The slight drop in the transparency of the films with hydrogen treatment is caused by scattering from pin-holes or nanostructures on the surface.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"2 1","pages":"11-14"},"PeriodicalIF":0.0,"publicationDate":"2009-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81513516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-01-21DOI: 10.2174/1874846500902010001
M. E. Glaoui, R. Kefi, E. Jeanneaub, F. Lefebvrec, C. Nasr
The new inorganic-organic hybrid complex of Zn(II) with 5-Chloro-2,4-dimethoxyaniline, (5-Cl-2,4- (OCH3)2C6H2NH3)2ZnCl4.3H2O, has been prepared and characterized by X-ray crystallography. The complex crystallizes in the triclinic space group P1 with a = 7.4614 (2), b = 9.8734 (2), c = 18.5678 (4) A, = 102.3578 (14), = 91.0686 (15), = 91.2373 (12)°, V = 1335.49 (5) A 3 , Z = 2. Crystal structure has been determined and refined to R = 0.035 and Rw = 0.036 using 5107 independent reflections. In the atomic arrangement of the title compound, ZnCl4 2- inorganic entities, water molecule and -NH3 + groups have a layered organization around the planes z = 1/4 and z = 3/4. The crystal structure
{"title":"Crystal Structure of Bis(5-Chloro-2,4-Dimethoxyanilinium) Tetrachlorozincate Trihydrate","authors":"M. E. Glaoui, R. Kefi, E. Jeanneaub, F. Lefebvrec, C. Nasr","doi":"10.2174/1874846500902010001","DOIUrl":"https://doi.org/10.2174/1874846500902010001","url":null,"abstract":"The new inorganic-organic hybrid complex of Zn(II) with 5-Chloro-2,4-dimethoxyaniline, (5-Cl-2,4- (OCH3)2C6H2NH3)2ZnCl4.3H2O, has been prepared and characterized by X-ray crystallography. The complex crystallizes in the triclinic space group P1 with a = 7.4614 (2), b = 9.8734 (2), c = 18.5678 (4) A, = 102.3578 (14), = 91.0686 (15), = 91.2373 (12)°, V = 1335.49 (5) A 3 , Z = 2. Crystal structure has been determined and refined to R = 0.035 and Rw = 0.036 using 5107 independent reflections. In the atomic arrangement of the title compound, ZnCl4 2- inorganic entities, water molecule and -NH3 + groups have a layered organization around the planes z = 1/4 and z = 3/4. The crystal structure","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"23 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2009-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81698834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-11-21DOI: 10.2174/1874846500801010056
J. Wong, R. Lalancette, H. W. Thompson
(±)-2-exo-Carboxy-2-endo-methyl-7-oxobicyclo[2.2.1]heptane exists preferentially in its closed, ringtautomer form, the tricyclic lactol (C9H12O3), which aggregates catemerically by forming hydroxyl-to-carbonyl hydrogen bonds [O O = 2.7667(16)A, O-H O = 170o] among molecules screw related in b. This ring-chain equilibrium is driven by relief of angular strain at the 7-ketone, whose origin is the ketone’s sp hybridization vs. the angle enforced by the bicyclic system. In the analogous compound with transposed functional groups, the equilibrium favors the keto acid, which
(±)-2-外羧基-2-内甲基-7-氧双环[2.2.1]庚烷优先以封闭的环异构体形式存在，即三环乳基(C9H12O3)，在图b中相关的分子中形成羟基-羰基氢键[O O = 2.7667(16)A, O- h O = 170o]，以双金属形式聚集。这种环链平衡是由7-酮的角应力解除驱动的，其起源是酮的sp杂化与双环系统施加的角度。在具有转置官能团的类似化合物中，平衡倾向于酮酸
{"title":"The Preferred Ring-Tautomeric Form of a Bicyclic γ-Ketocarboxylic Acid: An Equilibrium Driven by Relief of Angular Hybridization Strain","authors":"J. Wong, R. Lalancette, H. W. Thompson","doi":"10.2174/1874846500801010056","DOIUrl":"https://doi.org/10.2174/1874846500801010056","url":null,"abstract":"(±)-2-exo-Carboxy-2-endo-methyl-7-oxobicyclo[2.2.1]heptane exists preferentially in its closed, ringtautomer form, the tricyclic lactol (C9H12O3), which aggregates catemerically by forming hydroxyl-to-carbonyl hydrogen bonds [O O = 2.7667(16)A, O-H O = 170o] among molecules screw related in b. This ring-chain equilibrium is driven by relief of angular strain at the 7-ketone, whose origin is the ketone’s sp hybridization vs. the angle enforced by the bicyclic system. In the analogous compound with transposed functional groups, the equilibrium favors the keto acid, which","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"50 1","pages":"56-58"},"PeriodicalIF":0.0,"publicationDate":"2008-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80790660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-10-31DOI: 10.2174/1874846500801010051
J. Oueslati, O. Amri, E. Jeanneau, M. Rzaigui, C. Nasr
The atomic arrangement of the title compound, (4-NH2-6-OCH3-C4H3N2)2(H2PO4)2.H2O, can be described by inorganic layers of H2PO4 - anions and water molecules parallel to ab-plane at z = � and z = �, between which organic cations (4-NH2-6-OCH3-C4H3N2) + are located. The crystal packing is influenced by O-H…O, N-H…O, N-H…N and C- H…O hydrogen bonds. All ring atoms of the organic entity are coplanar. The exocyclic N atoms are electron receiving centers, which is consistent with features of imino resonance evidenced by bond lengths.
{"title":"Crystal Structure of a New Organic Dihydrogenmonophosphate Monohydrate[4-NH2-6-OCH3-C4H3N2]2(H2PO4)2.H2O","authors":"J. Oueslati, O. Amri, E. Jeanneau, M. Rzaigui, C. Nasr","doi":"10.2174/1874846500801010051","DOIUrl":"https://doi.org/10.2174/1874846500801010051","url":null,"abstract":"The atomic arrangement of the title compound, (4-NH2-6-OCH3-C4H3N2)2(H2PO4)2.H2O, can be described by inorganic layers of H2PO4 - anions and water molecules parallel to ab-plane at z = � and z = �, between which organic cations (4-NH2-6-OCH3-C4H3N2) + are located. The crystal packing is influenced by O-H…O, N-H…O, N-H…N and C- H…O hydrogen bonds. All ring atoms of the organic entity are coplanar. The exocyclic N atoms are electron receiving centers, which is consistent with features of imino resonance evidenced by bond lengths.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"17 1","pages":"51-55"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83717563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-10-31DOI: 10.2174/1874846500801010046
S. B. Dhas, J. Suresh, G. Bhagavannarayana, S. Natarajan
A new organic nonlinear optical (NLO) material L-Histidinium trifluoroacetate was crystallized using L- Histidine and trifluoroacetic acid in 1:1 stoichiometric ratio in water-ethanol medium. X-ray diffraction analysis of the single crystals showed that they belong to triclinic system, space group P1, with two molecules per unit cell. The lat- tice parameters are a = 5.1673(2) A, b = 8.8393(3) A, c = 12.4837(6) A, = 96.190(3)°, = 100.020(3)° and =102.010 (3)°. The molecules are held together by a three-dimensional network of hydrogen bonds. The crystalline perfection was studied by high resolution X-ray diffraction. The second harmonic generation (SHG) efficiency was measured by Kurtz and Perry method. The FTIR, UV-Vis-NIR spectra and TGA/DTA were recorded and studied. Vickers microhardness measurement was also carried out.
采用L-组氨酸与三氟乙酸按1:1的化学计量比在水-乙醇介质中结晶了一种新型有机非线性光学材料L-组氨酸。单晶的x射线衍射分析表明，它们属于三斜体系，空间群P1，每个细胞有两个分子。后期参数为a = 5.1673(2) a, b = 8.8393(3) a, c = 12.4837(6) a，= 96.190(3)°，= 100.020(3)°，=102.010(3)°。分子通过氢键的三维网络连接在一起。用高分辨率x射线衍射研究了晶体的完美性。采用Kurtz和Perry方法测量了二次谐波产生效率。记录并研究了FTIR、UV-Vis-NIR光谱和TGA/DTA。同时进行了维氏显微硬度测定。
{"title":"Growth and Characterization of a New Organic Non-Linear Optical (NLO) Material: L-Histidinium Trifluoroacetate","authors":"S. B. Dhas, J. Suresh, G. Bhagavannarayana, S. Natarajan","doi":"10.2174/1874846500801010046","DOIUrl":"https://doi.org/10.2174/1874846500801010046","url":null,"abstract":"A new organic nonlinear optical (NLO) material L-Histidinium trifluoroacetate was crystallized using L- Histidine and trifluoroacetic acid in 1:1 stoichiometric ratio in water-ethanol medium. X-ray diffraction analysis of the single crystals showed that they belong to triclinic system, space group P1, with two molecules per unit cell. The lat- tice parameters are a = 5.1673(2) A, b = 8.8393(3) A, c = 12.4837(6) A, = 96.190(3)°, = 100.020(3)° and =102.010 (3)°. The molecules are held together by a three-dimensional network of hydrogen bonds. The crystalline perfection was studied by high resolution X-ray diffraction. The second harmonic generation (SHG) efficiency was measured by Kurtz and Perry method. The FTIR, UV-Vis-NIR spectra and TGA/DTA were recorded and studied. Vickers microhardness measurement was also carried out.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"6 1","pages":"46-50"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83257606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-10-24DOI: 10.2174/1874846500801010042
S. B. Dhas, G. Bhagavannarayana, S. Natarajan
The single crystals of the NLO material, L-Alaninium maleate were grown by using the submerged seed solution method. The identity of the crystal was confirmed by single crystal X-ray diffraction. The crystalline perfection was analyzed using high resolution X-ray diffraction and it was found that the crystalline perfection is quite good. The values of the laser damage threshold and the Vicker’s microhardness are in the higher range. The dielectric studies at different temperatures showed that the dielectric constant and dielectric loss have low values at higher frequencies and these values are independent of the temperature. The details are presented and discussed. Keyword: X-ray diffraction, Growth from solution, Organic compound, Nonlinear optical materials.
{"title":"Growth, HRXRD, Microhardness and Dielectric Studies on the NLO Material L-Alaninium Maleate","authors":"S. B. Dhas, G. Bhagavannarayana, S. Natarajan","doi":"10.2174/1874846500801010042","DOIUrl":"https://doi.org/10.2174/1874846500801010042","url":null,"abstract":"The single crystals of the NLO material, L-Alaninium maleate were grown by using the submerged seed solution method. The identity of the crystal was confirmed by single crystal X-ray diffraction. The crystalline perfection was analyzed using high resolution X-ray diffraction and it was found that the crystalline perfection is quite good. The values of the laser damage threshold and the Vicker’s microhardness are in the higher range. The dielectric studies at different temperatures showed that the dielectric constant and dielectric loss have low values at higher frequencies and these values are independent of the temperature. The details are presented and discussed. Keyword: X-ray diffraction, Growth from solution, Organic compound, Nonlinear optical materials.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"27 1","pages":"42-45"},"PeriodicalIF":0.0,"publicationDate":"2008-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91552943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-09-22DOI: 10.2174/1874846500801010037
M. Percino, V. Chapela, Ling-Fa Montiel, Cecilia Rodríguez-Barbarín
The compound 1-(p-fluorophenyl)-2-(�-pyridyl)ethanol and its corresponding dehydration compound 1-(p- fluorophenyl)-2-(�-pyridyl)ethene were obtained from the Knoevenagel condensation reaction between 2-methylpyridine with p-fluorobenzaldehyde. The X-ray structure determined for 1-(p-fluorophenyl)-2-(�-pyridyl)ethanol reveals that the compound crystallizes in the monoclinic system space group, P21/n, containing four molecules in each crystal unit cell (a = 5.3664(15) A, b = 8.343(2) A, c = 25.056(6) A, and = 93.837(15)°). The crystal structure shows the formation of an intermolecular hydrogen bond O-H … N between the oxygen atom of the O-H and the nitrogen atom of a pyridine group of the next molecule. The condensation product 1-(p-fluorophenyl)-2-(2-pyridyl)ethene crystallizes in the monoclinic sys- tem, in the Cc space group, with unit cell dimensions a = 22.920(7) A, b = 5.9149(14) A, c = 7.8544(15) A, and = 104.16(2)°. The molecular structure shows the p-fluorophenyl ring attached to the double bond and located trans to the pyridine ring. The crystallography data give evidence that the intermediary compound is actually the alcohol just before the dehydration process that yields the trans double bond of the 1-(p-fluorophenyl)-2-(� -pyridyl)ethene.
通过2-甲基吡啶与对氟苯甲醛的Knoevenagel缩合反应，得到化合物1-(对氟苯基)-2-(-吡啶基)乙醇及其相应的脱水化合物1-(对氟苯基)-2-(-吡啶基)乙烯。对1-(对氟苯基)-2-(-吡啶基)乙醇的x射线结构测定表明，该化合物在单斜晶系空间群P21/n中结晶，每个晶胞中含有4个分子(a = 5.3664(15) a, b = 8.343(2) a, c = 25.056(6) a，= 93.837(15)°)。晶体结构表明在O-H的氧原子和下一个分子的吡啶基的氮原子之间形成了一个分子间氢键O-H…N。缩合产物1-(对氟苯基)-2-(2-吡啶基)乙烯以单斜晶系在Cc空间群中结晶，晶胞尺寸a = 22.920(7) a, b = 5.9149(14) a, c = 7.8544(15) a，= 104.16(2)°。分子结构为对氟苯基环与双键相连，与吡啶环反位。晶体学数据证明，中间化合物实际上是在脱水过程产生1-(对氟苯基)-2-(-吡啶基)乙烯的反式双键之前的醇。
{"title":"X-Ray Crystal Structures of a 1-(p-fluorophenyl)-2-(α-pyridyl)ethanol Intermediate and the 1-(p-fluorophenyl)-2-(α-pyridyl)ethene Dehydration Compound Obtained from the Condensation Reaction of 2-Methylpyridine and p-Fluorobenzaldehyde","authors":"M. Percino, V. Chapela, Ling-Fa Montiel, Cecilia Rodríguez-Barbarín","doi":"10.2174/1874846500801010037","DOIUrl":"https://doi.org/10.2174/1874846500801010037","url":null,"abstract":"The compound 1-(p-fluorophenyl)-2-(�-pyridyl)ethanol and its corresponding dehydration compound 1-(p- fluorophenyl)-2-(�-pyridyl)ethene were obtained from the Knoevenagel condensation reaction between 2-methylpyridine with p-fluorobenzaldehyde. The X-ray structure determined for 1-(p-fluorophenyl)-2-(�-pyridyl)ethanol reveals that the compound crystallizes in the monoclinic system space group, P21/n, containing four molecules in each crystal unit cell (a = 5.3664(15) A, b = 8.343(2) A, c = 25.056(6) A, and = 93.837(15)°). The crystal structure shows the formation of an intermolecular hydrogen bond O-H … N between the oxygen atom of the O-H and the nitrogen atom of a pyridine group of the next molecule. The condensation product 1-(p-fluorophenyl)-2-(2-pyridyl)ethene crystallizes in the monoclinic sys- tem, in the Cc space group, with unit cell dimensions a = 22.920(7) A, b = 5.9149(14) A, c = 7.8544(15) A, and = 104.16(2)°. The molecular structure shows the p-fluorophenyl ring attached to the double bond and located trans to the pyridine ring. The crystallography data give evidence that the intermediary compound is actually the alcohol just before the dehydration process that yields the trans double bond of the 1-(p-fluorophenyl)-2-(� -pyridyl)ethene.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"18 1","pages":"37-41"},"PeriodicalIF":0.0,"publicationDate":"2008-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75080076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-09-09DOI: 10.2174/1874846500801010031
W. Starosta, J. Leciejewicz
The monoclinic unit cell of Bis(hydrazineH) pyrazine-2,3-dicarboxylate contains singly protonated hydrazine cations and doubly deprotonated pyrazine-2,3-dicarboxylate anions. Atoms forming the pyrazine ring are coplanar (r.m.s. 0.0075(1) A). Carboxylate groups form dihedral angles with the pyrazine ring of 1.7(2)° (C7/O1/O2) and 89.3(2)° (C8/O3/O4). An extended hydrogen bond network is observed in which hydrazine N atoms act as donors in bonds to non- protonated carboxylate O and hetero-ring nitrogen atoms. The monoclinic structure of hydrazine adduct of pyrazine-2,5-dicarboxylic acid is composed of doubly-deprotonated pyrazine-2,5-dicarboxylate anions and singly-protonated hydrazine cations. The anions have their geometrical centres lo- cated at the inversion centres and are planar (r.m.s. 0.0009(1) A). Both carboxylic groups form dihedral angles of +11.7(1)° and -11.7(1)° with the pyrazine ring plane. Hydrazine cations acting as donors bridge the anions via weak hy- drogen bonds in which carboxylate O atoms are the acceptors giving rise to molecular layers. The structure of the adduct with pyrazine-2,6-dicarboxylic acid contains , apart from symmetry independent neutral hy- drazine molecules, symmetry independent acid molecules one half of them with protons attached to the carboxylate oxy- gen atoms as in the parent acid, the second half shows zwitterionic form with proton attached to the hetero-ring nitrogen atom. Carboxylic groups and the pyrazine ring are almost coplanar in both types of acid molecules. The latter are bridged by short hydrogen bonds of 2.435(2) and 2.426(2) A operating between carboxylate oxygen atoms belonging to adjacent symmetry independent acid molecules, forming layers composed of molecular ribbons. Hydrazine molecules acting as donors link the ribbons by a network of hydrogen bonds.
{"title":"The Crystal and Molecular Structures of Hydrazine Adducts with Isomeric Pyrazine Dicarboxylic Acids","authors":"W. Starosta, J. Leciejewicz","doi":"10.2174/1874846500801010031","DOIUrl":"https://doi.org/10.2174/1874846500801010031","url":null,"abstract":"The monoclinic unit cell of Bis(hydrazineH) pyrazine-2,3-dicarboxylate contains singly protonated hydrazine cations and doubly deprotonated pyrazine-2,3-dicarboxylate anions. Atoms forming the pyrazine ring are coplanar (r.m.s. 0.0075(1) A). Carboxylate groups form dihedral angles with the pyrazine ring of 1.7(2)° (C7/O1/O2) and 89.3(2)° (C8/O3/O4). An extended hydrogen bond network is observed in which hydrazine N atoms act as donors in bonds to non- protonated carboxylate O and hetero-ring nitrogen atoms. The monoclinic structure of hydrazine adduct of pyrazine-2,5-dicarboxylic acid is composed of doubly-deprotonated pyrazine-2,5-dicarboxylate anions and singly-protonated hydrazine cations. The anions have their geometrical centres lo- cated at the inversion centres and are planar (r.m.s. 0.0009(1) A). Both carboxylic groups form dihedral angles of +11.7(1)° and -11.7(1)° with the pyrazine ring plane. Hydrazine cations acting as donors bridge the anions via weak hy- drogen bonds in which carboxylate O atoms are the acceptors giving rise to molecular layers. The structure of the adduct with pyrazine-2,6-dicarboxylic acid contains , apart from symmetry independent neutral hy- drazine molecules, symmetry independent acid molecules one half of them with protons attached to the carboxylate oxy- gen atoms as in the parent acid, the second half shows zwitterionic form with proton attached to the hetero-ring nitrogen atom. Carboxylic groups and the pyrazine ring are almost coplanar in both types of acid molecules. The latter are bridged by short hydrogen bonds of 2.435(2) and 2.426(2) A operating between carboxylate oxygen atoms belonging to adjacent symmetry independent acid molecules, forming layers composed of molecular ribbons. Hydrazine molecules acting as donors link the ribbons by a network of hydrogen bonds.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"13 1","pages":"31-36"},"PeriodicalIF":0.0,"publicationDate":"2008-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72875011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-08-04DOI: 10.2174/1874846500801010024
Chun-sen Liu, Guang-Hui Sun, M. Li, Liang-Qi Guo, Zhou Liming, S. Fang
The reaction of AgNO3 with 1-(4-pyridylmethyl)-1H-benzotriazole (4-pbt) afforded a photoluminescent one- dimensional (1D) double-helical coordination polymer {(Ag(4-pbt))(NO3)}� (1) formed by interchain C-H � su- pramolecular interactions of the single-helical chains. Adjacent 1D double-helical motifs aforementioned were assembled into different two-dimensional (2D) sheets from the different crystallographic directions, respectively, by the co-effects of Ag O, C-H···O H-bonding, stacking, and C H supramolecular interactions. In comparision with the previous finding, the present work reveals that the N-donor spatial position of pendant pyridyl group in such benzotriazol-1-yl- based pyridyl ligands plays an important role on the final structures of relevant coordination complexes.
{"title":"A Double-Helical Silver(I) Coordination Polymer Based on 1-(4-pyridylmethyl)-1H-benzotriazole: Synthesis, Crystal Structure and Luminescent Property","authors":"Chun-sen Liu, Guang-Hui Sun, M. Li, Liang-Qi Guo, Zhou Liming, S. Fang","doi":"10.2174/1874846500801010024","DOIUrl":"https://doi.org/10.2174/1874846500801010024","url":null,"abstract":"The reaction of AgNO3 with 1-(4-pyridylmethyl)-1H-benzotriazole (4-pbt) afforded a photoluminescent one- dimensional (1D) double-helical coordination polymer {(Ag(4-pbt))(NO3)}� (1) formed by interchain C-H � su- pramolecular interactions of the single-helical chains. Adjacent 1D double-helical motifs aforementioned were assembled into different two-dimensional (2D) sheets from the different crystallographic directions, respectively, by the co-effects of Ag O, C-H···O H-bonding, stacking, and C H supramolecular interactions. In comparision with the previous finding, the present work reveals that the N-donor spatial position of pendant pyridyl group in such benzotriazol-1-yl- based pyridyl ligands plays an important role on the final structures of relevant coordination complexes.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"58 1","pages":"24-30"},"PeriodicalIF":0.0,"publicationDate":"2008-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86599615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-05-27DOI: 10.2174/1874846500801010014
K. Cai, L. Wang, J. L. Yin, C. W. Zhou
In order to synthesize Bi2Se3 nanopowders by a solvothermal synthesis method, ethylenediamine, dimethylformamide, acetone, absolute ethanol, and deionized water were respectively used as a solvent, using BiCl3 and elemental Se powders as starting materials and KBH4 as a reductant at 180 C for different times. X-ray diffraction was used for examining the phase composition of the products. The results showed that pure Bi2Se3 nanopowders were successfully synthesized only when deionized water was used as the solvent. Transmission electron microscopy observation revealed that the nanopowders consisted of big polygonal nanosheets and small irregular nanoparticles. The formation mechanism of the Bi2Se3 nanosheets and nanoparticles was proposed.
{"title":"Synthesis and Characterization of Bi2Se3 Thermoelectric Nanopowders","authors":"K. Cai, L. Wang, J. L. Yin, C. W. Zhou","doi":"10.2174/1874846500801010014","DOIUrl":"https://doi.org/10.2174/1874846500801010014","url":null,"abstract":"In order to synthesize Bi2Se3 nanopowders by a solvothermal synthesis method, ethylenediamine, dimethylformamide, acetone, absolute ethanol, and deionized water were respectively used as a solvent, using BiCl3 and elemental Se powders as starting materials and KBH4 as a reductant at 180 C for different times. X-ray diffraction was used for examining the phase composition of the products. The results showed that pure Bi2Se3 nanopowders were successfully synthesized only when deionized water was used as the solvent. Transmission electron microscopy observation revealed that the nanopowders consisted of big polygonal nanosheets and small irregular nanoparticles. The formation mechanism of the Bi2Se3 nanosheets and nanoparticles was proposed.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"2 1","pages":"14-17"},"PeriodicalIF":0.0,"publicationDate":"2008-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78160188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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