scholarly journals Crystal-to-Crystal Transformation from K2[Co(C2O4)2(H2O)2]·4H2O to K2[Co(μ-C2O4)(C2O4)]

2021 ◽  
Vol 7 (6) ◽  
pp. 77
Author(s):  
Bin Zhang ◽  
Yan Zhang ◽  
Guangcai Chang ◽  
Zheming Wang ◽  
Daoben Zhu
Keyword(s):  
Hydrogen Bond ◽  
Physical Properties ◽  
Crystal Structures ◽  
Molecular Crystal ◽  
Trigonal Prism ◽  
Space Group ◽  
Cell Parameters ◽  
Oxalate Anion ◽  
Crystal Transformation ◽  
Antiferromagnetic Ordering

Crystal-to-crystal transformation is a path to obtain crystals with different crystal structures and physical properties. K2[Co(C2O4)2(H2O)2]·4H2O (1) is obtained from K2C2O4·2H2O, CoCl2·6H2O in H2O with a yield of 60%. It is crystallized in the triclinic with space group P1 and cell parameters: a = 7.684(1) Å, b = 9.011(1) Å, c = 10.874(1) Å, α = 72.151(2)°, β = 70.278(2)°, γ = 80.430(2)°, V = 670.0(1) Å3, Z = 2 at 100 K. 1 is composed of K+, mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. Co2+ is coordinated by two bidentated oxalate anion and two H2O in an octahedron environment. There is a hydrogen bond between mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. K2[Co(μ-C2O4)(C2O4)] (2) is obtained from 1 by dehydration. The cell parameters of 2 are a = 8.460(5) Å, b = 6.906 (4) Å, c = 14.657(8) Å, β = 93.11(1)°, V = 855.0(8) Å3 at 100 K, with space group in P2/c. It is composed of K+ and zigzag [Co(μ-C2O4)(C2O42−]n chain. Co2+ is coordinated by two bisbendentate oxalate and one bidentated oxalate anion in trigonal-prism. 1 is an antiferromagnetic molecular crystal. The antiferromagnetic ordering at 8.2 K is observed in 2.

Crystallographic studies of BaR2ZnO5 (R=La, Nd, Dy, Ho, Er, and Y)

1998 ◽  
Vol 13 (3) ◽  
pp. 144-151 ◽  
Author(s):  
Winnie Wong-Ng ◽  
Brian Toby ◽  
William Greenwood
Keyword(s):  
Neutron Diffraction ◽  
Crystal Structures ◽  
Lattice Parameters ◽  
Trigonal Prism ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

The crystal structures of BaR2ZnO5, where R=La, Nd, Dy, Ho, and Y, were studied by neutron diffraction, and that of the Er analog was investigated by synchrotron X-ray diffraction. Two structure types were confirmed for this series of compounds and agreed with those reported in literature. The compounds with a smaller size of R (R=Dy, Ho, Y, and Er) are isostructural to the orthorhombic “green phase (BaY2CuO5)” compounds. The cell parameters for compounds with the R=Er to Dy range from a=7.0472(1) Å to 7.0944(1) Å, b=12.3022(1) Å to 12.3885(2) Å, and c=5.6958(1) Å to 5.7314(1) Å, respectively. R is 7-fold coordinated inside a monocapped trigonal prism. These prisms share edges to form wavelike chains parallel to the long b-axis. The Ba atoms reside in 11-fold coordinated cages. The compounds which contain a larger size R (R=La and Nd) crystallize in the tetragonal I4/mcm space group, but are not isostructural to the “brown phases” BaR2CuO5. The lattice parameters for the La and Nd analogs are a=6.9118(1) Å, c=11.6002(2) Å for BaLa2ZnO5, and a=6.7608(1) Å and c=11.5442(2) Å for BaLa2ZnO5. The structure consists of ZnO4 tetrahedral groups (instead of planar CuO4 groups as found in the brown phase) with Ba ions inserted in between. The structure can be viewed as consisting of alternate layers of Zn-Ba-O and Nd-O extending infinitely in the xy plane and perpendicular to the z-axis.

scholarly journals New crystal structures of adenylate kinase fromStreptococcus pneumoniaeD39 in two conformations

2014 ◽  
Vol 70 (11) ◽  
pp. 1468-1471
Author(s):  
Trung Thanh Thach ◽  
Sangho Lee
Keyword(s):  
Crystal Structures ◽  
Adenylate Kinase ◽  
Bound States ◽  
Critical Role ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters ◽  
Ligand Free ◽  
Adenylate Kinases

Adenylate kinases (AdKs; EC 2.7.3.4) play a critical role in intercellular homeostasis by the interconversion of ATP and AMP to two ADP molecules. Crystal structures of adenylate kinase fromStreptococcus pneumoniaeD39 (SpAdK) have recently been determined using ligand-free and inhibitor-bound crystals belonging to space groupsP21andP1, respectively. Here, new crystal structures of SpAdK in ligand-free and inhibitor-bound states determined at 1.96 and 1.65 Å resolution, respectively, are reported. The new ligand-free crystal belonged to space groupC2, with unit-cell parametersa= 73.5,b= 54.3,c= 62.7 Å, β = 118.8°. The new ligand-free structure revealed an open conformation that differed from the previously determined conformation, with an r.m.s.d on Cαatoms of 1.4 Å. The new crystal of the complex with the two-substrate-mimicking inhibitorP1,P5-bis(adenosine-5′-)pentaphosphate (Ap5A) belonged to space groupP1, with unit-cell parametersa= 53.9,b= 62.3,c= 63.0 Å, α = 101.9, β = 112.6, γ = 89.9°. Despite belonging to the same space group as the previously reported crystal, the new Ap5A-bound crystal contains four molecules in the asymmetric unit, compared with two in the previous crystal, and shows slightly different lattice contacts. These results demonstrate that SpAdK can crystallize promiscuously in different forms and that the open structure is flexible in conformation.

Supramolecular assembling using synthons with NH—CO(S)—CS—NH and NH—CO—CO—NH functionalities: crystal structures of (S,S)-N,N′-monothiooxalyldileucine methyl ester and its dithio analogue

2004 ◽  
Vol 60 (1) ◽  
pp. 90-96 ◽  
Author(s):  
Biserka Kojić-Prodić ◽  
Berislav Perić ◽  
Zoran Štefanić ◽  
Anton Meden ◽  
Janja Makarević ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Methyl Ester ◽  
Crystal Structures ◽  
Hydrogen Bond Network ◽  
Asymmetric Unit ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Bond Network ◽  
Bonding Systems

To compare the structural properties of oxalamide and thiooxalamide groups in the formation of hydrogen bonds suitable for supramolecular assemblies a series of retropeptides was studied. Some of them, having oxalamide bridges, are gelators of organic solvents and water. However, retropeptides with oxygen replaced by the sp 2 sulfur have not exhibited such properties. The crystal structures of the two title compounds are homostructural, i.e. they have similar packing arrangements. The monothio compound crystallizes in the orthorhombic space group P212121 with two molecules in the asymmetric unit arranged in a hydrogen-bond network with an approximate 41 axis along the crystallographic b axis. However, the dithio and dioxo analogues crystallize in the tetragonal space group P41 with similar packing patterns and hydrogen-bonding systems arranged in agreement with a crystallographic 41 axis. Thus, these two analogues are isostructural having closely related hydrogen-bonding patterns in spite of the different size and polarity of oxygen and sulfur which serve as the proton acceptors.

Isomers of 1,4,8,11-Tetraazacyclotetradecane-6,13-dicarboxylate Characterized as Cobalt(III) Complexes

2003 ◽  
Vol 56 (7) ◽  
pp. 679 ◽  
Author(s):  
Paul V. Bernhardt ◽  
Trevor W. Hambley ◽  
Geoffrey A. Lawrance ◽  
Marcel Maeder ◽  
Eric N. Wilkes
Keyword(s):  
Physical Properties ◽  
Octahedral Geometry ◽  
Trans Isomers ◽  
Space Group ◽  
Cell Parameters ◽  
Limited Distortion ◽  
Chelate Rings

The major trans (1) and minor cis (2) isomers of 1,4,8,11-tetraazacyclotetradecane-6,13-dicarboxylate have been characterized as the complexes [Co(1)](ClO4) and [Co(H2)(OH2)]Cl(ClO4)·H2O. The former crystallized in the C2/c space group and the latter in the P21/c space group, with cell parameters a 16.258(7), b 9.050(3), c 15.413(6) Å, β133.29(3)°, and a 9.694(4), b 16.135(1), c 12.973(5) Å, β 93.00(2)°, respectively. Their characterization completes identification of the respective trans and cis isomers for the series of c-pendant macrocycles also including 1,4,8,11-tetraazacyclotetradecane-6-amine-13-carboxylate ((3), (4)) and 1,4,8,11-tetraazacyclotetradecane-6,13-diamine ((5), (6)). The complexes show limited distortion from octahedral geometry with the strain in the presence of the coordinated c-pendant carboxylate significantly reduced compared with that for the c-pendant amine in analogues, a consequence mainly of six-membered as opposed to five-membered chelate rings involving the pendant donor. A comparison of the physical properties for the trans isomers of the octahedral complexes of (1), (3), and (5), which reflect progressively increasing strain, is presented.

Tautomerism and hydrogen bonding in guaninium phosphite and guaninium phosphate salts

2007 ◽  
Vol 63 (3) ◽  
pp. 448-458 ◽  
Author(s):  
El-Eulmi Bendeif ◽  
Slimane Dahaoui ◽  
Nourredine Benali-Cherif ◽  
Claude Lecomte
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Monoclinic Space Group ◽  
Data Sets ◽  
Hydrogen Bond Network ◽  
Space Group ◽  
X Ray ◽  
Bond Network ◽  
Phosphate Salts

The crystal structures of three similar guaninium salts, guaninium monohydrogenphosphite monohydrate, C5H6N5O+·H2O3P−·H2O, guaninium monohydrogenphosphite dihydrate, C5H6N5O+·H2O3P−·2H2O, and guaninium dihydrogenmonophosphate monohydrate, C5H6N5O+·H2O4P−·H2O, are described and compared. The crystal structures have been determined from accurate single-crystal X-ray data sets collected at 100 (2) K. The two phosphite salts are monoclinic, space group P21/c, with different packing and the monophosphate salt is also monoclinic, space group P21/n. An investigation of the hydrogen-bond network in these guaninium salts reveals the existence of two ketoamine tautomers, the N9H form and an N7H form.

Crystal-to-crystal transformation from a chain compound to a layered coordination polymer

2016 ◽  
Vol 45 (1) ◽  
pp. 89-92 ◽  
Author(s):  
Jinbiao Shi ◽  
Yan Zhang ◽  
Bin Zhang ◽  
Daoben Zhu
Keyword(s):  
Crystal Structure ◽  
Coordination Polymer ◽  
Antiferromagnetic Interaction ◽  
Space Group ◽  
Cell Parameters ◽  
Crystal Transformation ◽  
A Chain ◽  
Chain Compound

Crystal-to-crystal transformation from a chain compound CuBr2(1,4-dioxane)2(H2O)2 to a layered coordination polymer (CuBr2)3(1,4-dioxane)2 was observed with changes of crystal colour, cell parameters, space group, crystal structure, coordination environments of Cu2+, and enhanced antiferromagnetic interaction.

Structural studies of ligands for the glycine binding site of the excitatory amino acid receptor complex: 2. 6-bromo-, 6-methyl-, and 6-styryl-1,8-ethano-4-hydro-2,3-quinoxalinedione

1994 ◽  
Vol 72 (10) ◽  
pp. 2028-2036 ◽  
Author(s):  
Maciej Kubicki ◽  
Teresa W. Kindopp ◽  
Mario V. Capparelli ◽  
Penelope W. Codding
Keyword(s):  
Hydrogen Bond ◽  
Binding Site ◽  
Crystal Structures ◽  
Excitatory Amino Acid ◽  
Glycine Receptor ◽  
Three Dimensional ◽  
Unit Cell ◽  
Geometric Constraints ◽  
Cell Parameters ◽  
Π Stacking

The crystal structures of three tricyclic quinoxalinedione derivatives, 6-bromo-1,8-ethano-4-hydro-2,3-quinoxalinedione (1), 6-methyl-1,8-ethano-4-hydro-2,3-quinoxalinedione hydrate (2), and 6-styryl-1,8-ethano-4-hydro-2,3-quinoxalinedione (3), are reported. For 1 and 2, the space groups are P21/n with the unit cell parameters for 1: a = 7.4003(5) Å, b = 8.5799(5) Å, c = 14.3127(9) Å, β = 90.639(6)°, and for 2: a = 7.0590(2) Å, b = 10.7483(3) Å, c = 13.9509(7) Å, β = 103.290(3)°. For 3, the space group is P21/c, with a = 19.3683(10) Å, b = 8.0962(16) Å, c = 19.5801(16) Å, β = 114.028(6)°. Compound 3 crystallizes with two molecules in the asymmetric part of the unit cell; in one of them the styryl group is disordered. The geometries of the 1,8-ethano-4-hydro-2,3-quinoxalinedione fragments are similar in all observations, with the differences mainly caused by the different nature of the substituents in the 6-position. Hydrogen bonds connect the molecules into three-dimensional networks. Head-to-tail π-stacking between molecules connected by a center of symmetry determines the packing modes in 1 and 2 but there is no π-stacking in the crystal structure of 3. The crystal structures of the three quinoxaline derivative ligands for the glycine receptor suggest a mode of recognition that involves an [Formula: see text]receptor hydrogen bond, a three-centre hydrogen bond to the neighboring carbonyl groups on the ligand, and π-stacking between ligand and receptor. This mode is consistent with the geometric constraints of the current binding site model but places greater emphasis on hydrogen-bond interactions.

Structural studies of organoboron compounds. XXXIII. 4,4-Dimethyl-2,2-diphenyl-1,3-dioxa-4-azonia-2-boratacyclohexaneand 3,3-dimethyl-2-phenoxy-2-phenyl-1-oxa-3-azonia-2-boratacyclopentane

1989 ◽  
Vol 67 (5) ◽  
pp. 933-940 ◽  
Author(s):  
Eckardt Ebeling ◽  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Physical Properties ◽  
Crystal Structures ◽  
Direct Methods ◽  
Molecular Structures ◽  
Structural Studies ◽  
Boron Compounds ◽  
Organoboron Compounds ◽  
Thermally Induced ◽  
Full Matrix ◽  
Space Group

Details of the syntheses, physical properties, and crystal structures of the title compounds are reported. Crystals of 4,4-dimethyl-2,2-diphenyl-1,3-dioxa-4-azonia-2-boratacyclohexane, 3, are monoclinic, a = 6.512(1), b = 15.765(2), c = 14.342(4) Å, β = 93.170(7)°, Z = 4, space group Pn, and those of 3,3-dimethyl-2-phenoxy-2-phenyl-1-oxa-3-azonia-2-boratacyclopentane, 4, are orthorhombic, a = 13.5829(8), b = 16.940(1), c = 6.3181(4) Å, Z = 4, space group P21212. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.034 and 0.034 for 1974 and 1478 reflections with I ≥ 3σ(I), respectively. The molecular structures are discussed in terms of the thermally-induced 1,2-migration of B-substituents by which 3 is converted to 4. Keywords: crystal structures, boron compounds, organoboron compounds.

Structural studies of organoboron compounds. XXXII. 5,5-Difluoro-2,2-pentamethylene-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene and 2,2-pentamethylene-5,5-diphenyl-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene

1988 ◽  
Vol 66 (10) ◽  
pp. 2621-2630 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Mahmood Tajerbashi ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Solid State ◽  
Physical Properties ◽  
Least Squares ◽  
Crystal Structures ◽  
Direct Methods ◽  
Structural Studies ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
Conformational Isomers

Details of the syntheses, physical properties, and crystal structures of the title compounds are reported. Crystals of 5,5-difluoro-2,2-pentamethylene-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene are triclinic, a = 6.1576(3), b = 11.2651(3), c = 10.8118(3) Å, α = 109.747(3), β = 105.807(4), γ = 92.976(4)°, Z = 2, space group [Formula: see text], and those of 2,2-pentamethylene-5,5-diphenyl-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene are monoclinic, a = 9.8549(6), b = 10.9242(6), c = 41.263(2) Å, β = 92.717(6)°, Z = 8, space group P21/n. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.045 and 0.042 for 2344 and 4248 reflections with I ≥ 3σ(I), respectively. The molecules were both found to possess a seven-membered chelate structure, the O,O-chelatїng ligand being strongly bound to the X2B moiety. Two conformational isomers of the X = Ph compound were found in the solid state. The 2-oxazoline N-oxide moieties present in both compounds are the first to be structurally characterized. Important mean libration-corrected bond lengths are: O—B = 1.491 and F—B = 1.387 Å for X = F; O—B = 1.511 and C—B = 1.620 Å for X = Ph.

Syntheses, Crystal Structures and an Overview of Alkali Metal Maleates

2009 ◽  
Vol 64 (5) ◽  
pp. 517-524 ◽  
Author(s):  
Michel Fleck ◽  
Ladislav Bohatý
Keyword(s):  
Hydrogen Bond ◽  
Crystal Structures ◽  
Maleic Acid ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Space Group ◽  
Hydrogen Atom Position ◽  
Potassium Hydrogen ◽  
Intramolecular Hydrogen ◽  
Atom Position

The crystal structures of four alkali salts of maleic acid have been determined by single crystal X-ray diffraction: crystals of rubidium hydrogen maleate, RbH(C4H2O4), are very nearly centrosymmetrical, i. e., only one hydrogen atom position in the crystal structure violates the centrosymmetry. Thus, the space group is Pbc21 rather than Pbcm. The compound is isotypic with potassium hydrogen maleate, KH(C4H2O4), which has previously been described in space group Pbcm. It has been reinvestigated to prove that the correct space group is also Pbc21. The isotypic pair of rubidium hydrogen maleate maleic acid, RbH(C4H2O4) H2(C4H2O4), and caesium hydrogen maleate maleic acid, CsH(C4H2O4)H2(C4H2O4), crystallise in the triclinic space group P1̄. The geometry of the maleate units in these compounds corresponds well to data of other metal maleates. The only significant variation, concerning the intra-anionic hydrogen bond, is discussed. Furthermore, an overview of previously reported metal maleate structures is given, with special regard to the symmetry of the intramolecular hydrogen bond.

Sign in / Sign up

Export Citation Format

Share Document