B4/32Ga28/32Sb10/32As22/32 Three-Dimensional Semiconductor Superlattice

Author(s):  
Viacheslav Elyukhin ◽  
Ramon Peña Sierra

Abstract Self-assembly of BD -rich A x B 1-x C y D 1-y was studied for a lot of semiconductor alloys. An occurrence of identical clustersshould be due to a decrease of the bond energy, internal strain energy or both of them. An arrangement of the clusters is disordered since the contents of minority atoms are in the dilute or ultra dilute limits in the considered alloys. B 4/32 Ga 28/32 Sb 10/32 As 22/32 semiconductor alloy with the three-dimensional superlattice is presented. This superlattice should be stable against disordering due to its minimal free energy. The superlattice forms by the identical cubic units consisting of 64 atoms and is the three-dimensional semiconductor soft X-ray diffraction grating.

2018 ◽  
Vol 74 (8) ◽  
pp. 889-893
Author(s):  
Qian-Kun Zhou ◽  
Lin Wang ◽  
Dong Liu

As a class of multifunctional materials, crystalline supramolecular complexes have attracted much attention because of their unique architectures, intriguing topologies and potential applications. In this article, a new supramolecular compound, namely catena-poly[4,4′-(buta-1,3-diene-1,4-diyl)dipyridin-1-ium [(μ4-benzene-1,2,4,5-tetracarboxylato-κ6 O 1,O 1′:O 2:O 4,O 4′:O 5)cadmium(II)]], {(C14H14N2)[Cd(C10H2O8)]} n or {(1,4-H2bpbd)[Cd(1,2,4,5-btc)]} n , has been prepared by the self-assembly of Cd(NO3)2·4H2O, benzene-1,2,4,5-tetracarboxylic acid (1,2,4,5-H4btc) and 1,4-bis(pyridin-4-yl)buta-1,3-diene (1,4-bpbd) under hydrothermal conditions. The title compound has been structurally characterized by IR spectroscopy, elemental analysis, powder X-ray diffraction and single-crystal X-ray diffraction analysis. Each CdII centre is coordinated by six O atoms from four different (1,2,4,5-btc)4− tetraanions. Each CdII cation, located on a site of twofold symmetry, binds to four carboxylate groups belonging to four separate (1,2,4,5-btc)4− ligands. Each (1,2,4,5-btc)4− anion, situated on a position of \overline{1} symmetry, binds to four crystallographically equivalent CdII centres. Neighbouring CdII cations interconnect bridging (1,2,4,5-btc)4− anions to form a three-dimensional {[Cd(1,2,4,5-btc)]2−} n anionic coordination network with infinite tubular channels. The channels are visible in both the [1\overline{1}0] and the [001] direction. Such a coordination network can be simplified as a (4,4)-connected framework with the point symbol (4284)(4284). To balance the negative charge of the metal–carboxylate coordination network, the cavities of the network are occupied by protonated (1,4-H2bpbd)2+ cations that are located on sites of twofold symmetry. In the crystal, there are strong hydrogen-bonding interactions between the anionic coordination network and the (1,4-H2bpbd)2+ cations. Considering the hydrogen-bonding interactions, the structure can be further regarded as a three-dimensional (4,6)-connected supramolecular architecture with the point symbol (4264)(42687·84). The thermal stability and photoluminescence properties of the title compound have been investigated.


2017 ◽  
Vol 73 (4) ◽  
pp. 314-318 ◽  
Author(s):  
Xu Wei ◽  
Jian-Hua Li ◽  
Qiu-Ying Huang ◽  
Xiang-Ru Meng

The unsymmetrical N-heterocyclic ligand 1-[(benzotriazol-1-yl)methyl]-1H-1,3-imidazole (bmi) has three potential N-atom donors and can act in monodentate or bridging coordination modes in the construction of complexes. In addition, the bmi ligand can adopt different coordination conformations, resulting in complexes with different structures due to the presence of the flexible methylene spacer. Two new complexes, namely bis{1-[(benzotriazol-1-yl)methyl]-1H-1,3-imidazole-κN3}dibromidomercury(II), [HgBr2(C10H9N5)2], and bis{1-[(benzotriazol-1-yl)methyl]-1H-1,3-imidazole-κN3}diiodidomercury(II), [HgI2(C10H9N5)2], have been synthesized through the self-assembly of bmi with HgBr2or HgI2. Single-crystal X-ray diffraction shows that both complexes are mononuclear structures, in which the bmi ligands coordinate to the HgIIions in monodentate modes. In the solid state, both complexes display three-dimensional networks formed by a combination of hydrogen bonds and π–π interactions. The IR spectra and PXRD patterns of both complexes have also been recorded.


2012 ◽  
Vol 67 (11) ◽  
pp. 1191-1196 ◽  
Author(s):  
Chong-Zhen Mei ◽  
Kai-Hui Li ◽  
Hai-Hua Li

Self-assembly of silver(I) cations, flexible 2,2ʹ-oxydibenzoate anions (L2-), and 1,2-bis(4- pyridyl)ethane (bpa) ligands affords a new three-dimensional supramolecular architecture, {[Ag2(L)(bpa)2]⋅(H2O)4}n (1), which has been characterized by elemental analysis, IR, TGA, PXRD, and single-crystal X-ray diffraction. Complex 1exhibits layers further connected through hydrogen bonding and π...π stacking interactions. Its photoluminescence was also investigated.


1980 ◽  
Vol 209 (1175) ◽  
pp. 275-297 ◽  

A theory of the three-dimensional structure of the collagen fibril outlined by Woodhead-Galloway (1977) is discussed in greater detail and an account of the low angle X-ray diffraction pattern (Miller & Wray 1971) is obtained. Square-packed dimers form the overlap region of the fibril. In the gap region, clusters of four dimers at each of the points of a square lattice of side 3.8 nm provide the structure. Molecules are parallel to the axis of the fibril in the overlap region and tilted from the axis by a few degrees in the gap region. A brief discussion of some aspects of the self assembly of such a structure is included. In particular, it is noted that the axially projected D ( ═ 66.8 nm) period, which is a property of the Whole fibril, is not necessarily also a local property; there may be no well defined and finite small grouping of molecules that is itself D -periodic, such as is proposed in the microfibril model of the fibril (Smith 1968). On the other hand, there is strong circumstantial evidence of a D -periodic crystallographic unit cell.


2013 ◽  
Vol 68 (2) ◽  
pp. 138-146 ◽  
Author(s):  
Hong-Yan Lin ◽  
Peng Liu ◽  
Xiu-Li Wang ◽  
Chuang Xu ◽  
Guo-Cheng Liu

Two new copper(II) complexes, [Cu2(3-bpfp)(2,6-PDA)2(H2O)2] (1) and [Cu(4-bpfp)0:5 (glu)]·H2O (2), have been hydrothermally synthesized by self-assembly of isomeric bis(pyridylformyl)piperazine ligands [3-bpfp=bis(3-pyridylformyl)piperazine, 4-bpfp=bis(4- pyridylformyl)piperazine], rigid pyridine-2,6-dicarboxylic acid (2,6-H2PDA) or flexible glutaric acid (H2glu), and copper(II) chloride. Single-crystal X-ray diffraction analysis reveals that two adjacent CuII ions are connected by the 3-bpfp ligand to build a dinuclear unit in complex 1, in which 2,6-PDA serves as a terminal chelating ligand. Adjacent dinuclear units are further linked by hydrogen bonding and π-π stacking interactions to form a three-dimensional (3D) supramolecular network. Complex 2 is a 3D coordination polymeric framework based on a layer polymer [Cu(glu)]n and bridging 4-bpfp ligands with 6-connected (44.610.8) topology. In 1 and 2, the ligands 3-bpfp and 4-bpfp adopt a μ2-bridging coordination mode (via ligation of pyridyl nitrogen atoms). The thermal stability and the electrochemical properties of the title complexes have been studied.


2018 ◽  
Vol 74 (9) ◽  
pp. 1053-1057 ◽  
Author(s):  
Qian-Kun Zhou ◽  
Lin Wang ◽  
Yun Xu ◽  
Ni-Ya Li

In recent years, coordination polymers constructed from multidentate carboxylate and pyridyl ligands have attracted much attention because these ligands can adopt a rich variety of coordination modes and thus lead to the formation of crystalline products with intriguing structures and interesting properties. A new coordination polymer, namely poly[[μ2-1,6-bis(pyridin-3-yl)-1,3,5-hexatriene-κ2 N:N′](μ3-naphthalene-1,4-dicarboxylato-κ4 O 1,O 1′:O 4:O 4′)zinc(II)], [Zn(C12H6O4)(C16H14N2)] n , has been prepared by the self-assembly of Zn(NO3)2·6H2O, naphthalene-1,4-dicarboxylic acid (1,4-H2ndc) and 1,6-bis(pyridin-3-yl)-1,3,5-hexatriene (3,3′-bphte) under hydrothermal conditions. The title compound has been structurally characterized by IR spectroscopy, elemental analysis, powder X-ray diffraction and single-crystal X-ray diffraction analysis. Each ZnII ion is six-coordinated by four O atoms from three 1,4-ndc2− ligands and by two N atoms from two 3,3′-bphte ligands, forming a distorted octahedral ZnO4N2 coordination geometry. Pairs of ZnII ions are linked by 1,4-ndc2− ligands, leading to the formation of a two-dimensional square lattice (sql) layer extending in the ab plane. In the crystal, adjacent layers are further connected by 3,3′-bphte bridges, generating a three-dimensional architecture. From a topological viewpoint, if each dinuclear zinc unit is considered as a 6-connected node and the 1,4-ndc2− and 3,3′-bphte ligands are regarded as linkers, the structure can be simplified as a unique three-dimensional 6-connected framework with the point symbol 446108. The thermal stability and solid-state photoluminescence properties have also been investigated.


2014 ◽  
Vol 10 (6) ◽  
pp. 2864-2874
Author(s):  
Deepanjali Pandey ◽  
Shahid S.Narvi ◽  
Siddhartha Chaudhuri

A new three dimensional hydrogen bonded cobalt frame work from [Co(nicotinamide)2(thiocyanate)2(H2O)2] was synthesized and characterized by X-ray diffraction, magnetism ,TGA and IR spectroscopy. The compound crystallizes in Triclinic space group P-1 with a = 7.5475(19), b = 8.054(2), c =8.932(2). Alpha=73.347(4), beta=70.067(4), gamma=66.559(4) with space group P-1 Z = 1, 'C14 H16 N6 Co O4 S2', Mr =455.38, F(000) = 233 and μ(MoKα) =0.71073 mm-1. The final R = 0.0497 and wR = 0.1461 for 4185 observed reflections with I > 2σ(I) and R = 0.0721 and wR = 0.1619 for all data. X-ray diffraction analyses revealed that Co(1) is linked by the nicotinamide ligands to form the ladder shape along the c axis, which is further extended into two-dimensional networks via the joint of Co(2) along the a axis. Moreover, these two dimensional motifs are interconnected by the thiocyanate S...H bridges to form a complicated 3-D polymeric framework. The magnetic susceptibility data at 1000Oe external field in the temperature range 2-300 K obeys the Curie-Weiss law, giving θ = -24.12 K and C =2.43  thus indicating a dominant strong antiferromagnetic interaction and/or spin orbital coupling between the Co (II) ions. 


2019 ◽  
Vol 75 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Zhen Chen ◽  
Yanwen Sun ◽  
Zi-an Liu ◽  
Ning Wang ◽  
Xue Yang ◽  
...  

In recent years, coordination polymers constructed from multidentate carboxylate ligands and N-containing ligands have attracted much attention since these ligands can adopt a rich variety of coordination modes which can lead to crystalline products with intriguing structures and interesting properties. A new coordination polymer, namely poly[[diaqua[μ-2,7-bis(1H-imidazol-1-yl)fluorene-κ2 N 3:N 3′][μ-5,5′-methylenebis(3-carboxy-2,4,6-trimethylbenzoato)-κ2 O 1:O 1′]zinc(II)] hemihydrate], {[Zn(C23H22O8)(C19H14N4)(H2O)2]·0.5H2O} n , 1, was prepared by the self-assembly of Zn(NO3)2·6H2O with 5,5′-methylenebis(2,4,6-trimethylisophthalic acid) (H4BTMIPA) and 2,7-bis(1H-imidazol-1-yl)fluorene (BIF) under solvothermal conditions. The structure of 1 was determined by elemental analysis, single-crystal X-ray crystallography, powder X-ray diffraction, IR spectroscopy and thermogravimetric analysis. Each ZnII ion is six-coordinated by two O atoms from two H2BTMIPA2− ligands, by two N atoms from two BIF ligands and by two water molecules, forming a distorted octahedral ZnN2O4 coordination geometry. Adjacent ZnII ions are linked by H2BTMIPA2− ligands and BIF ligands, leading to the formation of a two-dimensional (2D) (4,4)-sql network, and intermolecular hydrogen-bonding interactions connect the 2D layer structure into the three-dimensional (3D) supramolecular structure. Each 2D layer contains two kinds of helices with the same direction, which are opposite in adjacent layers. The luminescence properties of complex 1 in the solid state have also been investigated.


2008 ◽  
Vol 2008 (10) ◽  
pp. 584-586 ◽  
Author(s):  
Fayan Meng ◽  
Yuanhong Jiao ◽  
Xuemei Chen ◽  
Lei Teng

A self-assembled, tetrameric water cluster stabilised by carboxyl-bridging has been characterised by X-ray diffraction studies and thermogravimetric analysis. Every water cluster is connected strongly via hydrogen bonds to four carboxyl oxygens of a terephthalate anion. The water rings are stable at room temperature, but when thermally decomposed, the water loss is irreversible.


2019 ◽  
Vol 75 (7) ◽  
pp. 990-995 ◽  
Author(s):  
Wenlong Lan ◽  
Zhen Zhou ◽  
Fu-Chao Jia ◽  
Xiaoyun Hao ◽  
Yong Dou ◽  
...  

A new coordination polymer (CP), namely poly[(μ-4,4′-bipyridine)(μ3-3,4′-oxydibenzoato)cobalt(II)], [Co(C14H8O5)(C10H8N2)] n or [Co(3,4′-obb)(4,4′-bipy)] n (1), was prepared by the self-assembly of Co(NO3)2·6H2O with the rarely used 3,4′-oxydibenzoic acid (3,4′-obbH2) ligand and 4,4′-bipyridine (4,4′-bipy) under solvothermal conditions, and has been structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray crystallography and powder X-ray diffraction (PXRD). Single-crystal X-ray diffraction reveals that each CoII ion is six-coordinated by four O atoms from three 3,4′-obb2− ligands, of which two function as monodentate ligands and the other as a bidentate ligand, and by two N atoms from bridging 4,4′-bipy ligands, thereby forming a distorted octahedral CoN2O4 coordination geometry. Adjacent crystallographically equivalent CoII ions are bridged by the O atoms of 3,4′-obb2− ligands, affording an eight-membered Co2O4C2 ring which is further extended into a two-dimensional [Co(3,4′-obb)] n sheet along the ab plane via 3,4′-obb2− functioning as a bidentate bridging ligand. The planes are interlinked into a three-dimensional [Co(3,4′-obb)(4,4′-bipy)] n network by 4,4′-bipy ligands acting as pillars along the c axis. Magnetic investigations on CP 1 disclose an antiferromagnetic coupling within the dimeric Co2 unit and a metamagnetic behaviour at low temperature resulting from intermolecular π–π interactions between the parallel 4,4′-bipy ligands.


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