A new three-dimensional anionic cadmium(II) dicyanamide network

2014 ◽  
Vol 70 (11) ◽  
pp. 1054-1056 ◽  
Author(s):  
Qiang Li ◽  
Hui-Ting Wang
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Unit Cell Volume ◽  
Three Dimensional ◽  
Building Blocks ◽  
The Other ◽  
Dimensional Structure ◽  
Cadmium Nitrate ◽  
Nitrate Tetrahydrate ◽  
Anionic Framework

A new cadmium dicyanamide complex, poly[tetramethylphosphonium [μ-chlorido-di-μ-dicyanamido-κ4N1:N5-cadmium(II)]], [(CH3)4P][Cd(NCNCN)2Cl], was synthesized by the reaction of tetramethylphosphonium chloride, cadmium nitrate tetrahydrate and sodium dicyanamide in aqueous solution. In the crystal structure, each CdIIatom is octahedrally coordinated by four terminal N atoms from four anionic dicyanamide (dca) ligands and by two chloride ligands. The dicyanamide ligands play two different roles in the building up of the structure; one role results in the formation of [Cd(dca)Cl]2building blocks, while the other links the building blocks into a three-dimensional structure. The anionic framework exhibits a solvent-accessible void of 673.8 Å3, amounting to 47.44% of the total unit-cell volume. The cavities in the network are occupied by pairs of tetramethylphosphonium cations.

scholarly journals trans-Bis(2,2′-bipyridine-4,4′-dicarboxylic acid-κ2 N,N′)dichloridoruthenium(III) perchlorate

IUCrData ◽  
2018 ◽  
Vol 3 (11) ◽  
Author(s):  
Lívia Gonçalves Leida Soares ◽  
Diego Silva Padilha ◽  
Roberto Salgado Amado ◽  
Marciela Scarpellini
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Carboxylic Acid ◽  
Dicarboxylic Acid ◽  
Three Dimensional ◽  
The Other ◽  
Dimensional Structure ◽  
Hydrogen Bonding Interactions ◽  
Octahedral Environment ◽  
Small Distortion

In the crystal structure of the ruthenium(III) complex, trans-[RuIII(dcbpy)2Cl2]ClO4 (dcbpy = 2,2′-bipyridine-4,4′-dicarboxylic acid, C12H8N2O4), the RuIII atom lies on an inversion centre, showing a small distortion in its octahedral environment. The Ru—Cl bond lengths are shorter than those present in the analogous trans-ruthenium(II) compound containing the bipyridine ligand. The C—O distances in the two symmetry-independent carboxylic acid moieties of the ligand are similar in one group, but different in the other. This is probably due to the different intermolecular interactions they experience with neighbouring cationic complexes. The hydrogen-bonding interactions in which they are involved form a three-dimensional structure, similar to those found in coordination polymers.

A two-dimensional anionic CdIIpolymer constructed through dicyanamide coordination bridges

2015 ◽  
Vol 71 (8) ◽  
pp. 717-720 ◽  
Author(s):  
Hui-Ting Wang ◽  
Lin Zhou ◽  
Xiao-Li Wang
Keyword(s):  
Crystal Structure ◽  
Solid Phase ◽  
Inorganic Compounds ◽  
Three Dimensional ◽  
Ferroelectric Materials ◽  
Organic Cations ◽  
Supramolecular Network ◽  
Cadmium Nitrate ◽  
Two Dimensional ◽  
Nitrate Tetrahydrate

In the search for potential ferroelectric materials, molecular-based one-, two- and three-dimensional cadmium(II) organic–inorganic compounds have been of interest as they often display solid–solid phase transitions induced by a variation in temperature. A new cadmium dicyanamide complex, poly[4-dimethylamino-1-ethylpyridin-1-ium [tri-μ-dicyanamido-κ6N1:N5-cadmium(II)]], {(C9H15N2)[Cd(C2N3)3]}n, was synthesized by the reaction of 4-dimethylamino-1-ethylpyridin-1-ium bromide, cadmium nitrate tetrahydrate and sodium dicyanamide in aqueous solution. In the crystal structure, each CdIIcation is octahedrally coordinated by six terminal N atoms from six anionic dicyanamide (dca) ligands. Neighbouring CdIIcations are linked together by dicyanamide bridges to form a two-dimensional coordination polymer. The organic cations are not involved in the formation of the supramolecular network.

scholarly journals Structure of Human Cyclophilin A in Complex with the Novel Immunosuppressant Sanglifehrin A at 1.6 Å Resolution

2005 ◽  
Vol 280 (23) ◽  
pp. 21965-21971 ◽  
Author(s):  
Joerg Kallen ◽  
Richard Sedrani ◽  
Gerhard Zenke ◽  
Juergen Wagner
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Cyclophilin A ◽  
The Other ◽  
Size Exclusion ◽  
Dimensional Structure ◽  
The Novel ◽  
Immunosuppressive Activity ◽  
Exclusion Chromatography ◽  
Sanglifehrin A

Sanglifehrin A (SFA) is a novel immunosuppressant isolated from Streptomyces sp. that binds strongly to the human immunophilin cyclophilin A (CypA). SFA exerts its immunosuppressive activity through a mode of action different from that of all other known immunophilin-binding substances, namely cyclosporine A (CsA), FK506, and rapamycin. We have determined the crystal structure of human CypA in complex with SFA at 1.6 Å resolution. The high resolution of the structure revealed the absolute configuration at all 17 chiral centers of SFA as well as the details of the CypA/SFA interactions. In particular, it was shown that the 22-membered macrocycle of SFA is deeply embedded in the same binding site as CsA and forms six direct hydrogen bonds with CypA. The effector domain of SFA, on the other hand, has a chemical and three-dimensional structure very different from CsA, already strongly suggesting different immunosuppressive mechanisms. Furthermore, two CypA·SFA complexes form a dimer in the crystal as well as in solution as shown by light scattering and size exclusion chromatography experiments. This observation raises the possibility that the dimer of CypA·SFA complexes is the molecular species mediating the immunosuppressive effect.

scholarly journals Ammonium imidazolium dichromate

2012 ◽  
Vol 68 (4) ◽  
pp. m389-m389 ◽  
Author(s):  
Run-Qiang Zhu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
The Other ◽  
Dimensional Structure ◽  
Compound C ◽  
The Mean ◽  
Anions And Cations ◽  
Dichromate Anions

In the crystal structure of the title compound, (C3H5N2)(NH4)[Cr2O7], the anions and cations are linked through N—H...O hydrogen bonds, resulting in a three-dimensional structure which contains three kinds of layers parallel to (001). One layer contains imidazole cations, the other two layers the ammonium cations and dichromate anions. The dichromate anion has an eclipsed conformation with a dihedral angle of 14.65 (18)° between the mean planes of the O—P—O—P—O backbone.

A new two-dimensional anionic cadmium(II) polymer constructed through thiocyanate coordination bridges

2015 ◽  
Vol 71 (4) ◽  
pp. 318-321 ◽  
Author(s):  
Hui-Ting Wang ◽  
Xiao-Li Wang
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Hydrogen Bonds ◽  
Building Blocks ◽  
The Other ◽  
Supramolecular Network ◽  
Stacking Interactions ◽  
Two Dimensional ◽  
Thiocyanate Complex ◽  
Dimensional Network

A new cadmium–thiocyanate complex, poly[4-(dimethylamino)pyridin-1-ium [di-μ-thiocyanato-κ2N:S;κ2S:N-thiocyanato-κN-cadmium(II)]], {(C7H11N2)[Cd(NCS)3]}n, was synthesized by the reaction of cadmium thiocyanate and 4-(dimethylamino)pyridine hydrochloride in aqueous solution. In the crystal structure, each CdIIion is square-pyramidally coordinated by three N and two S atoms from five different thiocyanate ligands, four of which are bridging. The thiocyanate ligands play different roles in the build up of the structure; one role results in the formation of [Cd2(NCS)2] building blocks, while the other links the building blocks and cationsviaN—H...S hydrogen bonds. The N—H...S hydrogen bonds and weak π–π stacking interactions are involved in the formation of both a two-dimensional network structure and the supramolecular network.

Poly[[diaquabis(μ4-benzene-1,3-dicarboxylato)(μ3-benzene-1,3-dicarboxylato)dierbium(III)] monohydrate]

2007 ◽  
Vol 63 (11) ◽  
pp. m2826-m2827
Author(s):  
Wen-Dong Song ◽  
De-Yun Ma ◽  
Chao-Hua Zhang
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Hydrothermal Reaction ◽  
Three Dimensional ◽  
The Other ◽  
Water Molecules ◽  
Bridging Ligands ◽  
Solvent Water ◽  
Hydrogen Bonding Interactions ◽  
Dimensional Network

The title erbium coordination polymer, {[Er2(C8H4O4)3(H2O)2]·H2O} n , was obtained by the hydrothermal reaction of ErCl3 with benzene-1,3-dicarboxylic acid (1,3-BDC) in alkaline aqueous solution. Each of the two crystallographically independent ErIII ions is seven-coordinate and has a distorted pentagonal–bipyramidal geometry. One Er centre is coordinated by seven O atoms from six 1,3-BDC ligands and the other Er centre is surrounded by five O atoms from five 1,3-BDC ligands and two water molecules. The bridging ligands, which have two different coordination modes, link the metal centres to form a three-dimensional network with channels parallel to the b axis in which solvent water molecules are located. The crystal structure is stabilized by intra- and intermolecular O—H...O hydrogen-bonding interactions. One benzene ring and the solvent water molecule are independently disordered over two positions each, with occupancy ratios of 0.595 (2):0.405 (2) and 0.661 (1):0.339 (1), respectively.

scholarly journals Redetermination of [EuCl2(H2O)6]Cl

2014 ◽  
Vol 70 (6) ◽  
pp. i27-i27 ◽  
Author(s):  
Frank Tambornino ◽  
Philipp Bielec ◽  
Constantin Hoch
Keyword(s):  
Crystal Structure ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Building Blocks ◽  
Structure Type ◽  
Chloride Anion ◽  
The Other ◽  
Water Molecules ◽  
Atomic Coordinates ◽  
The Eu

The crystal structure of the title compound, hexaaquadichloridoeuropium(III) chloride, was redetermined with modern crystallographic methods. In comparison with the previous study [Lepertet al.(1983).Aust. J. Chem.36, 477–482], it could be shown that the atomic coordinates of some O atoms had been confused and now were corrected. Moreover, it was possible to freely refine the positions of the H atoms and thus to improve the accurracy of the crystal structure. [EuCl2(H2O)6]Cl crystallizes with the GdCl3·6H2O structure-type, exhibiting discrete [EuCl2(H2O)6]+cations as the main building blocks. The main blocks are linked with isolated chloride anionsviaO—H...Cl hydrogen bonds into a three-dimensional framework. The Eu3+cation is located on a twofold rotation axis and is coordinated in the form of a Cl2O6square antiprism. One chloride anion coordinates directly to Eu3+, whereas the other chloride anion, situated on a twofold rotation axis, is hydrogen bonded to six octahedrally arranged water molecules.

The first crystal structure of the peptidase domain of the U32 peptidase family

2015 ◽  
Vol 71 (12) ◽  
pp. 2505-2512 ◽  
Author(s):  
Magdalena Schacherl ◽  
Angelika A. M. Montada ◽  
Elena Brunstein ◽  
Ulrich Baumann
Keyword(s):  
Crystal Structure ◽  
Catalytic Mechanism ◽  
Quaternary Structure ◽  
Catalytic Domain ◽  
Three Dimensional ◽  
Zinc Ion ◽  
Crystal Structure Analysis ◽  
Dimensional Structure ◽  
Sequence Motifs ◽  
Conserved Sequence

The U32 family is a collection of over 2500 annotated peptidases in the MEROPS database with unknown catalytic mechanism. They mainly occur in bacteria and archaea, but a few representatives have also been identified in eukarya. Many of the U32 members have been linked to pathogenicity, such as proteins fromHelicobacterandSalmonella. The first crystal structure analysis of a U32 catalytic domain fromMethanopyrus kandleri(genemk0906) reveals a modified (βα)8TIM-barrel fold with some unique features. The connecting segment between strands β7 and β8 is extended and helix α7 is located on top of the C-terminal end of the barrel body. The protein exhibits a dimeric quaternary structure in which a zinc ion is symmetrically bound by histidine and cysteine side chains from both monomers. These residues reside in conserved sequence motifs. No typical proteolytic motifs are discernible in the three-dimensional structure, and biochemical assays failed to demonstrate proteolytic activity. A tunnel in which an acetate ion is bound is located in the C-terminal part of the β-barrel. Two hydrophobic grooves lead to a tunnel at the C-terminal end of the barrel in which an acetate ion is bound. One of the grooves binds to aStrep-Tag II of another dimer in the crystal lattice. Thus, these grooves may be binding sites for hydrophobic peptides or other ligands.

scholarly journals Crystal structure of 2-benzylamino-4-(4-methoxyphenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-3-carbonitrile

2014 ◽  
Vol 70 (12) ◽  
pp. 525-527 ◽  
Author(s):  
R. A. Nagalakshmi ◽  
J. Suresh ◽  
S. Maharani ◽  
R. Ranjith Kumar ◽  
P. L. Nilantha Lakshman
Keyword(s):  
Crystal Structure ◽  
Pyridine Ring ◽  
Three Dimensional ◽  
Chair Conformation ◽  
Dimensional Structure ◽  
Compound C ◽  
Centroid Distance ◽  
Steric Crowding ◽  
Benzene Rings ◽  
Group A

The title compound, C25H25N3O, comprises a 2-aminopyridine ring fused with a cycloheptane ring, which adopts a chair conformation. The central pyridine ring (r.m.s. deviation = 0.013 Å) carries three substituents,viz.a benzylamino group, a methoxyphenyl ring and a carbonitrile group. The N atom of the carbonitrile group is significantly displaced [by 0.2247 (1) Å] from the plane of the pyridine ring, probably due to steric crowding involving the adjacent substituents. The phenyl and benzene rings are inclined to one another by 58.91 (7)° and to the pyridine ring by 76.68 (7) and 49.80 (6)°, respectively. In the crystal, inversion dimers linked by pairs of N—H...Nnitrilehydrogen bonds generateR22(14) loops. The dimers are linked by C—H...π and slipped parallel π–π interactions [centroid–centroid distance = 3.6532 (3) Å] into a three-dimensional structure.

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