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.

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.

scholarly journals Preparation, Structure and Investigations of BEDT-TTF Trihalides

1985 ◽  
Vol 40 (12) ◽  
pp. 1664-1671 ◽  
Author(s):  
H. Endres ◽  
M. Hiller ◽  
H. J. Keller
Keyword(s):  
Physical Properties ◽  
Unit Cell ◽  
Oxidation Reactions ◽  
Unit Cell Parameters ◽  
Triclinic Space Group ◽  
Space Group ◽  
Cell Parameters

Abstract Crystals of the β-phases of (BEDT-TTF)2Br-I-Br (1) and (BEDT-TTF)2I-I - Br (2) have been isolated by electrocrystallization. The solids can be obtained using different tetrabutylammonium trihalides containing iodine and bromine as supporting electrolytes. Cyclovoltam metric results show clearly that the trihalide anions are involved in the oxidation reactions near the anode which finally lead to the crystals. 1 C20H16Br2IS16, Mr = 1056.01, and 2 C20H16BrI2S16, Mt = 1103.01 are isom orphous, crystallizing in the triclinic space group P1̄, with Z = 1. Unit cell parameters for 1: a = 6.5979(6) A , b = 8.998(1) Å, c = 15.138(3) Å , a = 94.03(1)°, β = 95.13(1), γ = 110.28(1), V = 834.7 Å and for 2: α = 6.606(2) Å , b = 9.047(6) A , c = 15.229(6) Å, α = 94.28(2)°, β = 95.34(2), v = 109.92(2), V = 846.5 Å3. The different sizes of the Br2I- and Brl2- counterions lead to different intra- and interstack S -S contacts in the solids thus influencing the physical properties. An additional Br2I- phase with a modulation of the above-described structure could be found. Some relevant physical properties of 1 and 2 are reported

The Crystal and Molecular-Structure of Two Complexes of Cobalt(III) With Pentaaza Macrocyclic Ligands Chloro (1,4,7,10,14-pentaazacycloheptadecane)cobalt(III) Bromide Chloride Hydrate [Co(C12H29N5)Cl] (Br0.33Cl1.67)H2O and Bromo(1,4,7,11,15-pentaazacyclooctadecane)cobalt(III) Bromide [Co(C13H31N5)Br]Br2

1987 ◽  
Vol 40 (5) ◽  
pp. 829 ◽  
Author(s):  
NF Curtis ◽  
GJ Gainsford ◽  
P Osvath ◽  
DC Weatherburn
Keyword(s):  
Chelate Ring ◽  
Octahedral Geometry ◽  
Distorted Octahedral Geometry ◽  
Boat Conformation ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Membered Chelate Ring ◽  
Ligand Interactions ◽  
Chloride Hydrate ◽  
Chelate Rings

The structures of the compounds chloro (1,4,7,10,14-pentaazacycloheptadecane) cobalt(III) bromide chloride hydrate, [Co( chad )Cl] ( Br0.33Cl1.67)H2O(1) and bromo (1,4,7,11,15-pentaazacyclooctadecane) cobalt(III) bromide, [Co( coad )Br]Br2(2),have been determined by X-ray diffractometry. [Compound (1) orthorhombic, space group P bac, a 1208.5, b 2305.5, c 1318.9 pm, Z 8, R 0.056, Rw 0.071 for 1943 reflections. Compound (2), triclinic, space group P1, a 930.8, b 953.5, c 1120.3pm, α 84.60,β 398.82, γ 105.26�, Z 2, R 0.045, RW0.054 for 4821 reflections.] The compounds have structures with two ( chad ) or three ( coad ) six-membered chelate rings in the equatorial (N4) plane, but with different configurations of the chiral nitrogen centres ; chad : 1SR , 4SR, 7RS, 10RS, that is, with only the NH group at the junction of the two six-membered chelate rings on the same side of the N4 plane as the axial nitrogen; coad : 1 RS, 7SR, 11 SR, 15RS, that is, with NH groups of the central six-membered chelate ring on the same side of the N4 plane as the axial nitrogen, and the others on the opposite side. The chad compound has regular octahedral geometry, with one chair and one boat conformation six-membered chelate ring. The coad compound has distorted octahedral geometry, with long Co-N distances in the N4 plane, attributed to intra-ligand interactions.

Synthesis of cis- and trans-platinum compounds with pyrimidine and crystal structures of trans-[Pt(pyrimidine)2X2] where X = Cl and Br

1981 ◽  
Vol 59 (2) ◽  
pp. 195-198 ◽  
Author(s):  
F. D. Rochon ◽  
P. C. Kong ◽  
R. Melanson
Keyword(s):  
Crystal Structures ◽  
Platinum Atom ◽  
Platinum Compounds ◽  
X Ray Diffraction ◽  
Trans Isomers ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Cis And Trans

cis- and trans-[Pt(pm)2X2] where pm = pyrimidine and X = Cl, Br, have been synthesized. The cis-compounds were isolated from the reaction of K2PtCl4 and pm in water, while the trans-isomers were obtained by isomerization of cis-[Pt(pm2X2] in DMF in the presence of pm.The crystal structures of the two compounds trans-[Pt(pm)2X2] have been determined by X-ray diffraction. The two compounds (X = Br and Cl) are isostructural. The crystals belong to the monoclinic P21/c space group. The cell parameters are a = 4.787(3), b = 14.257(7), c = 8.503(3) Å and β = 99.33(4)° when X = Cl and a = 4.826(3), b = 14.822(5), c = 8.516(5) Å and β = 101.26(4)° when X = Br. The platinum atom is located on a centre of symmetry at the origin and Z = 2. The residual factors are R = 0.029 and Rw = 0.036 (X = Cl) and R = 0.036 and Rw = 0.035 (X = Br).

Two lithium tricyanomethanide compounds: syntheses and single-crystal structure determination of LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO

2015 ◽  
Vol 70 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Structure Determination ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Cell Parameters ◽  
New Compounds

AbstractThe new compounds LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO were synthesized and their crystal structures were determined. Li[C(CN)3]·½ (H3C)2CO crystallizes in the orthorhombic space group Ima2 (no. 46) with the cell parameters a=794.97(14), b=1165.1(2) and c=1485.4(3) pm, while LiK[C(CN)3]2 adopts the monoclinic space group P21/c (no. 14) with the cell parameters a=1265.7(2), b=1068.0(2) and c=778.36(12) pm and the angle β=95.775(7)°. Single crystals of K[C(CN)3] were also acquired, and the crystal structure was refined more precisely than before corroborating earlier results.

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.

Intergrowth polytypoids as modulated structures: a superspace description of the Sr n (Nb,Ti) n O3n + 2 compound series

2001 ◽  
Vol 57 (4) ◽  
pp. 471-484 ◽  
Author(s):  
L. Elcoro ◽  
J. M. Perez-Mato ◽  
R. L. Withers
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Separation Distance ◽  
Space Group ◽  
Space Groups ◽  
Cell Parameters ◽  
Average Structure ◽  
Layer Stacking ◽  
Compound Series ◽  
Three Dimensional Space

A new, unified superspace approach to the structural characterization of the perovskite-related Sr n (Nb,Ti) n O3n + 2 compound series, strontium niobium/titanium oxide, is presented. To a first approximation, the structure of any member of this compound series can be described in terms of the stacking of (110)-bounded perovskite slabs, the number of atomic layers in a single perovskite slab varying systematically with composition. The various composition-dependent layer-stacking sequences can be interpreted in terms of the structural modulation of a common underlying average structure. The average interlayer separation distance is directly related to the average structure periodicity along the layer stacking direction, while an inherent modulation thereof is produced by the presence of different types of layers (particularly vacant layers) along this stacking direction. The fundamental atomic modulation is therefore occupational and can be described by means of crenel (step-like) functions which define occupational atomic domains in the superspace, similarly to what occurs for quasicrystals. While in a standard crystallographic approach, one must describe each structure (in particular the space group and cell parameters) separately for each composition, the proposed superspace model is essentially common to the whole compound series. The superspace symmetry group is unique, while the primary modulation wavevector and the width of some occupation domains vary linearly with composition. For each rational composition, the corresponding conventional three-dimensional space group can be derived from the common superspace group. The resultant possible three-dimensional space groups are in agreement with all the symmetries reported for members of the series. The symmetry-breaking phase transitions with temperature observed in many compounds can be explained in terms of a change in superspace group, again in common for the whole compound series. Inclusion of the incommensurate phases, present in many compounds of the series, lifts the analysis into a five-dimensional superspace. The various four-dimensional superspace groups reported for this incommensurate phase at different compositions are shown to be predictable from a proposed five-dimensional superspace group apparently common to the whole compound series. A comparison with the scarce number of refined structures in this system and the homologous (Nb,Ca)6Ti6O20 compound demonstrates the suitability of the proposed formalism.

New Perovskite Based Structures in the Bi-Sr-O System

1992 ◽  
Vol 275 ◽  
Author(s):  
Bokhimi ◽  
M. Portilla
Keyword(s):  
Cell Parameter ◽  
Crystalline Phases ◽  
Space Group ◽  
Crystalline Structures ◽  
Cell Parameters ◽  
Group I

ABSTRACTWe report one amorphous and four new crystalline phases in the Bi-Sr-0 system. The structure of three of the crystalline phases was identified. The Br10Bi6O24-y phase, which is cubic with space group Fm3m and cell parameter a = 0.8471(1) nm. The SreBi10O27-y phase, which is tetragonal with the space group I/mmm, and cell parameters a = 0.6007(1), c = 0.8376(1) nm. The SreBi10O27-y phase, which is tetragonal with space group I/mmm and cell parameters a = 1.3221(1), c = 0.4249(1) nm. We show that in the crystalline structures Sr and Bi occupy equivalent sites.

Monoclinic and Hexagonal Nepheline Structures of (Na3/4/K1/4)AlGeO4

1998 ◽  
Vol 54 (3) ◽  
pp. 211-220 ◽  
Author(s):  
R. P. Hammond ◽  
J. Barbier
Keyword(s):  
Large Family ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Silicate Mineral ◽  
Tetrahedral Framework ◽  
Space Group ◽  
Cell Parameters ◽  
Monoclinic Form ◽  
Hexagonal Form ◽  
Alkali Atoms

Hexagonal (Na3/4K1/4)AlGeO4 crystallizes in the space group P63 with unit-cell parameters a = 10.164 (2), c = 8.540 (2) Å and Z = 8 [wR(F 2) = 0.066 for all 3060 independent reflections]. Monoclinic (Na3/4K1/4)AlGeO4 crystallizes in the space group P21 with unit-cell parameters a = 10.0477 (4), b = 8.5764 (4), c = 10.2118 (4) Å, β = 119.035 (1)° and Z = 8 [wR(F 2) = 0.120 for all 3194 independent reflections measured on a twinned crystal]. Both structures belong to the large family of stuffed tridymites, with the Al and Ge atoms occupying tetrahedral sites, and the alkali atoms occupying the cavities of the tetrahedral framework. Hexagonal (Na3/4K1/4)AlGeO4 is isostructural with the silicate mineral nepheline (Na3/4K1/4)AlSiO4, while monoclinic (Na3/4K1/4)AlGeO4 corresponds to a minor distortion of the nepheline structure. Chemical analysis by electron microprobe and structure determination of flux-grown single crystals indicate that the hexagonal form with the chemical formula (Na0.78K0.19)Al0.97Ge1.03O4 may be stabilized by an alkali deficiency similar to that found in hexagonal natural nephelines. In contrast, all alkali sites are fully occupied in the monoclinic form of composition (Na0.75K0.25)AlGeO4 and the lower symmetry eliminates the oxygen disorder present in the hexagonal form.

X-ray powder diffraction data for tetrazene nitrate monohydrate, C2H9N11O4

2021 ◽  
pp. 1-3
Author(s):  
J. Maixner ◽  
J. Ryšavý
Keyword(s):  
Cell Volume ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

X-ray powder diffraction data, unit-cell parameters, and space group for tetrazene nitrate monohydrate, C2H9N11O4, are reported [a = 5.205(1) Å, b = 13.932(3) Å, c = 14.196(4) Å, β = 97.826(3)°, unit-cell volume V = 1019.8(4) Å3, Z = 4, and space group P21/c]. All measured lines were indexed and are consistent with the P21/c space group. No detectable impurities were observed.

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