Self-Assembly of a Three-Dimensional Supramolecular Structure Based on Carboxyl-Bridged Tetrameric Water Clusters

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.

2014 ◽  
Vol 70 (11) ◽  
pp. 1025-1028
Author(s):  
Hong Shen

The title CdIIcoordination polymer, [Cd(C10H8O4)(C12H12N6)0.5(H2O)]n, has been obtained by the hydrothermal method and studied by single-crystal X-ray diffraction, elemental analysis, thermogravimetric analysis, IR spectroscopy and fluorescence spectroscopy. The compound forms a novel three-dimensional framework with 3,8-connected three-dimensional binodal {4.52}2{42.510.612.7.83} topology. An investigation of its photoluminescence properties shows that the compound exhibits a strong fluorescence emission in the solid state at room temperature.


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.


2011 ◽  
Vol 66 (5) ◽  
pp. 459-464 ◽  
Author(s):  
Chao Xu ◽  
Sheng-Bo Liu ◽  
Taike Duan ◽  
Qun Chen ◽  
Qian-Feng Zhang

Two novel cadmium coordination polymers, [Cd(pydc)2(tu)]n (1) and [Cd2(SO4)(nic)2(tu)1.5 - (H2O)2]n (2) (pydc = pyridine-2,3-dicarboxylate, nic = nicotinate, tu = thiourea), have been synthesized under hydrothermal conditions and structurally characterized by X-ray diffraction analysis. 1 is a one-dimensional ladder coordination polymer in a two-dimensional network formed by hydrogen bonds. 2 consists of two kinds of Cd(II) centers in different coordination environments connected via nicotinate and sulfate to form a two-dimensional grid network integrated in a three-dimensional framework generated by hydrogen bonds. 2 shows intense fluorescent emission in the solid state at room temperature


Author(s):  
Karolina Schwendtner ◽  
Uwe Kolitsch

The crystal structures of hydrothermally synthesized silver(I) aluminium bis[hydrogen arsenate(V)], AgAl(HAsO4)2, silver(I) gallium bis[hydrogen arsenate(V)], AgGa(HAsO4)2, silver gallium diarsenate(V), AgGaAs2O7, and sodium gallium diarsenate(V), NaGaAs2O7, were determined from single-crystal X-ray diffraction data collected at room temperature. The first two compounds are representatives of the MCV-3 structure type known for KSc(HAsO4)2, which is characterized by a three-dimensional anionic framework of corner-sharing alternatingM3+O6octahedra (M= Al, Ga) and singly protonated AsO4tetrahedra. Intersecting channels parallel to [101] and [110] host the Ag+cations, which are positionally disordered in the Ga compound, but not in the Al compound. The hydrogen bonds are relatively strong, with O...O donor–acceptor distances of 2.6262 (17) and 2.6240 (19) Å for the Al and Ga compounds, respectively. The two diarsenate compounds are representatives of the NaAlAs2O7structure type, characterized by an anionic framework topology built ofM3+O6octahedra (M= Al, Ga) sharing corners with diarsenate groups, andM+cations (M= Ag) hosted in the voids of the framework. Both structures are characterized by a staggered conformation of the As2O7groups.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Rawia Nasri ◽  
Regaya Ksiksi ◽  
Mohsen Graia ◽  
Mohamed Faouzi Zid

A new 2,6-bis aminomethyl piperidine decavanadate hydrate, (C7N3H20)2V10O28.4.21H2O, was synthesized by slow evaporation of a solution at room temperature. The molecular structure was investigated by single-crystal X-ray diffraction. In the crystal structure, the layers of decavanadate groups, organic cations, and water molecules are arranged parallel to the (010) plane. Also, the prepared compound has been analysed by FTIR spectroscopy and scanning electron microscopy (SEM). The crystal structure of the title compound is stabilized by hydrogen bonds and van der Waals interactions. The cohesion of the structure is ensured by O-H…O and N-H…O hydrogen bonds. The three-dimensional Hirshfeld surface (3D-HS) and the relative two-dimensional fingerprint plots (2D-FPs) of (C7N3H20)2V10O28.4.21H2O compound revealed that the structure is dominated by O…H/H…O (70.8%) and H…H (18.5%) contacts.


IUCrJ ◽  
2014 ◽  
Vol 1 (2) ◽  
pp. 136-150 ◽  
Author(s):  
Palash Sanphui ◽  
Geetha Bolla ◽  
Ashwini Nangia ◽  
Vladimir Chernyshev

Acemetacin (ACM) is a non-steroidal anti-inflammatory drug (NSAID), which causes reduced gastric damage compared with indomethacin. However, acemetacin has a tendency to form a less soluble hydrate in the aqueous medium. We noted difficulties in the preparation of cocrystals and salts of acemetacin by mechanochemical methods, because this drug tends to form a hydrate during any kind of solution-based processing. With the objective to discover a solid form of acemetacin that is stable in the aqueous medium, binary adducts were prepared by the melt method to avoid hydration. The coformers/salt formers reported are pyridine carboxamides [nicotinamide (NAM), isonicotinamide (INA), and picolinamide (PAM)], caprolactam (CPR),p-aminobenzoic acid (PABA), and piperazine (PPZ). The structures of an ACM–INA cocrystal and a binary adduct ACM–PABA were solved using single-crystal X-ray diffraction. Other ACM cocrystals, ACM–PAM and ACM–CPR, and the piperazine salt ACM–PPZ were solved from high-resolution powder X-ray diffraction data. The ACM–INA cocrystal is sustained by the acid...pyridine heterosynthon and N—H...O catemer hydrogen bonds involving the amide group. The acid...amide heterosynthon is present in the ACM–PAM cocrystal, while ACM–CPR contains carboxamide dimers of caprolactam along with acid–carbonyl (ACM) hydrogen bonds. The cocrystals ACM–INA, ACM–PAM and ACM–CPR are three-dimensional isostructural. The carboxyl...carboxyl synthon in ACM–PABA posed difficulty in assigning the position of the H atom, which may indicate proton disorder. In terms of stability, the salts were found to be relatively stable in pH 7 buffer medium over 24 h, but the cocrystals dissociated to give ACM hydrate during the same time period. The ACM–PPZ salt and ACM–nicotinamide cocrystal dissolve five times faster than the stable hydrate form, whereas the ACM–PABA adduct has 2.5 times faster dissolution rate. The pharmaceutically acceptable piperazine salt of acemetacin exhibits superior stability, faster dissolution rate and is able to overcome the hydration tendency of the reference drug.


Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4431 ◽  
Author(s):  
Lingshu Meng ◽  
Lun Zhao ◽  
Guanlin Guo ◽  
Xin Liu ◽  
Zhijun Liang ◽  
...  

In this study, three new 3D coordination polymers (CPs), {[Cd3(L)(H2O)6]·H2O}n (1), {[Cu1.5(L)0.5(bimb)1.5]·5H2O·DMF}n (2), and {[Mn1.5(H3L)(bibp)0.5(H2O)2]·3H2O}n (3) (bimb= 1,3-bis(imidazol-1-yl)benzene, bibp= 1,4-bis((4-imidazol-1-yl)benzyl)piperazine), were prepared under solvothermal or hydrothermal conditions based on a hexadentate ligand (1,3,5-triazine-2,4,6-triamine hexa-acetic acid (H6L)). Structural elucidations were carried out by IR spectra along with single-crystal X-ray diffraction analysis, while thermogravimetric analysis (TGA) (dynamic and isothermal) and XRD techniques were used for property evaluations of the polymers. Furthermore, the fluorescence properties and detection of the Fe3+ ions in 1 were tested at room temperature, and the electrochemical behavior of 2 is also stated in this article.


1988 ◽  
Vol 32 ◽  
pp. 609-616 ◽  
Author(s):  
D. Chandra ◽  
C. S. Barrett ◽  
D. K. Benson

AbstractAn array of molecules that is anisotropic in the extreme has been discovered in certain thermal-energy storage materials and is reported here: neopentylglycol (NPG) and NPG-rich solid solutions with pentaglycerine (PG) have a crystal structure, stable at room temperature, that consists of bimolecular chains of molecules that are all unidirectionally aligned throughout a crystal. There are hydrogen bonds between every molecule in one chain and its neighbors in that chain, but none between molecules of one chain and any molecules of the neighboring parallel chains. Thus there are strong intermolecular bonds along each chain and only weaker bonds between the chains. The structure has been determined by using modern single crystal techniques with 529 independent reflections from a crystal of NPG (C5H12O2). The structure is monoclinic with space group P21/c - C2h5. This anisotropic structure transforms to a cubic structure at higher temperatures.


2017 ◽  
Vol 73 (8) ◽  
pp. 600-608 ◽  
Author(s):  
Karolina Schwendtner ◽  
Uwe Kolitsch

The crystal structures of hydrothermally synthesized aluminium dihydrogen arsenate(V) dihydrogen diarsenate(V), Al(H2AsO4)(H2As2O7), gallium dihydrogen arsenate(V) dihydrogen diarsenate(V), Ga(H2AsO4)(H2As2O7), and diindium bis[dihydrogen arsenate(V)] bis[dihydrogen diarsenate(V)], In2(H2AsO4)2(H2As2O7)2, were determined from single-crystal X-ray diffraction data collected at room temperature. The first two compounds are representatives of a novel sheet structure type, whereas the third compound crystallizes in a novel framework structure. In all three structures, the basic building units areM3+O6octahedra (M= Al, Ga, In) that are connectedviaone H2AsO4−and two H2As2O72−groups into chains, and furtherviaH2As2O72−groups into layers. In Al/Ga(H2AsO4)(H2As2O7), these layers are interconnected by weak-to-medium–strong hydrogen bonds. In In2(H2AsO4)2(H2As2O7)2, the H2As2O72−groups link the chains in three dimensions, thus creating a framework topology, which is reinforced by weak-to-medium–strong hydrogen bonds. The three title arsenates represent the first compounds containing both H2AsO4−and H2As2O72−groups.


2010 ◽  
Vol 65 (2) ◽  
pp. 152-156
Author(s):  
Di Sun ◽  
Cheng-Feng Yang ◽  
Zhan-Hua Wei ◽  
Geng-Geng Luo ◽  
Na Zhang ◽  
...  

A new three-dimensional (3D) supramolecular framework, [Ag2(bipy)2(bdc)·4H2O]n 1, has been synthesized by the ultrasonic reaction of Ag2O, bipy and H2bdc (H2bdc = 1,4-benzenedicarboxylic acid; bipy = 4,4’-bipyridine) at room temperature. It exhibits a new 3D supramolecular framework which is built from cationic Ag-bipy chains and anionic bdc-H2O sheets through hydrogen bonds, π · · ·π stacking and C-H· · ·π interactions. Additionally, the photoluminescent and thermal properties of 1 were investigated.


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