The crystal chemistry of duftite, PbCuAsO4(OH) and the β-duftite problem

1998 ◽  
Vol 62 (1) ◽  
pp. 121-130 ◽  
Author(s):  
Kharisun ◽  
Max R. Taylor ◽  
D. J. M Bevan ◽  
Allan Pring

AbstractDuftite, PbCu(AsO4)(OH) is orthorhombic, space group P212121 with a = 7.768(1), b = 9. 211(1), c = 5.999(1) Å, Z = 4; the structure has been refined to R = 4.6% and Rw = 6.5% using 640 observed reflections [F> 2σ(F)]. The structure consists of chains of edge-sharing CuO6 ‘octahedra’, parallel to c; which are linked via AsO4 tetrahedra and Pb atoms in distorted square antiprismatic co-ordination to form a three dimensional network. The CuO6 ‘octahedra’ show Jahn-Teller distortion with the elongation running approximately along <627>. The hydrogen bonding network in the structure was characterized using bond valence calculations. ‘β-duftite’ is an intermediate in the duftite-conichalcite series, which has a modulated structure based on the intergrowth of the two structures in domains of approximately 50 Å. The origin of the modulation is thought to be associated with displacements in the oxygen lattice and is related to the orientation of the Jahn-Teller distortion of CuO6 ‘octahedra’. Approximately half of the strips show an elongation parallel to <627> while the other strips are elongated parallel to [010]. This ordering results in an increase in the b cell repeat compared to duftite and conichalcite.

2017 ◽  
Vol 73 (6) ◽  
pp. 442-446 ◽  
Author(s):  
Duyen N. K. Pham ◽  
Mrittika Roy ◽  
James A. Golen ◽  
David R. Manke

The crystal structures of the first-row transition-metal series of tris(ethylenediamine-κ2 N,N′)metal(II) diacetate, [M(C2H8N2)3](CH3CO2)2, with M = Mn, Fe, Co, Ni, Cu, and Zn, are reported. The complexes are all isostructural, crystallizing in a centrosymmetric triclinic cell and possessing an asymmetric unit composed of one [M(en)3]2+ cation and two symmetrically independent acetate anions. In the unit cell, the two complex cations are inversion-generated enantiomers, possessing the energetically favoured Δ(λλλ) and Λ(δδδ) configurations. The complex cations and acetate anions combine through a series of N—H...O hydrogen bonds to generate a three-dimensional network in the crystals. The other notable feature of the series is a significant Jahn–Teller distortion for the d 9 Cu2+ complex.


2014 ◽  
Vol 70 (6) ◽  
pp. m222-m223
Author(s):  
Amani Direm ◽  
Wahiba Falek ◽  
Guillaume Pilet ◽  
Nourredine Benali-Cherif

The asymmetric unit of the title compound, [Cu(C2H8N2)2(H2O)2](C11H11N4O2S)2, contains one sulfamerazinate anion in a general position and one half-cation that is located on a center of inversion. The CuIIcation shows a strong Jahn–Teller distortion. It is coordinated by four N atoms of two ethylenediamine ligands in the basal plane and two O atoms at much longer distances in the axial positions in a bipyramidal coordination. In the crystal, the building blocks are connected by N—H...N, O—H...N, N—H...O and O—H...O hydrogen bonding into a two-dimensional network parallel to (001).


2014 ◽  
Vol 70 (11) ◽  
pp. m372-m373 ◽  
Author(s):  
Ya-Ping Li ◽  
Dajun Sun ◽  
Julia Ming ◽  
Liying Han ◽  
Guan-Fang Su

The molecular components of the title salt, [Cu(C4H11NO2)2](C8H4O4), are one CuIIcationO,N,O′-chelated by two tridentate 2-[(2-hydroxyethyl)amino]ethanol ligands, and a terephthalate counter-dianion, located about a centre of inversion. The complex CuIIcation is located about a centre of inversion and shows typical Jahn–Teller distortion, with two short Cu—O and two short Cu—N bonds in the equatorial plane and two long Cu—O bonds to the axial atoms. The cations are arranged in sheets parallel to (100), with the centrosymmetric terephthalate anions located between the sheets. Each anion is the acceptor of four O—H...O and two N—H...O hydrogen bonds, forming a three-dimensional network structure.


1995 ◽  
Vol 60 (9) ◽  
pp. 1429-1434
Author(s):  
Martin Breza

Using semiempirical CNDO-UHF method the adiabatic potential surface of 2[Cu(OH)6]4- complexes is investigated. The values of vibration and vibronic constants for Eg - (a1g + eg) vibronic interaction attain extremal values for the optimal O-H distance. The Jahn-Teller distortion decreases with increasing O-H distance. The discrepancy between experimentally observed elongated bipyramid of [Cu(OH)6]4- in Ba2[Cu(OH)6] and the compressed one obtained by quantum-chemical calculation is explainable by hydrogen bonding of the axial hydroxyl group.


2004 ◽  
Vol 59 (8) ◽  
pp. 943-946 ◽  
Author(s):  
Viktor Hlukhyy ◽  
Rainer Pöttgen

AbstractThe hexagonal Laves phase MgIr2 was synthesized from the elements in a sealed tantalum tube in an induction furnace. MgIr2 was investigated by powder and single crystal X-ray data: P63/mmc, a = 516.9(1), c = 838.5(2) pm, wR2 = 0.0771, 135 F2 values, and 11 variable parameters. The magnesium atoms have coordination number (CN) 16 (12 Ir + 4 Mg), while the smaller iridium atoms, Ir1 and Ir2, both have CN 12 (6 Ir + 6 Mg). The Ir-Ir distances within the three-dimensional network of face- and corner-sharing Ir4/2 tetrahedra range from 250 to 267 pm. The magnesium atoms have one shorter (306 pm) and three longer (319 pm) magnesium contacts. The crystal chemistry of MgIr2 is briefly discussed and compared with the other binary Mg-Ir intermetallics.


2017 ◽  
Vol 73 (10) ◽  
pp. 1479-1482 ◽  
Author(s):  
Rita Egekenze ◽  
Yilma Gultneh ◽  
Ray J. Butcher

The title compound, [Mn(C16H17N2O3)2(C2H6OS)2]ClO4·0.774CH3OH, comprises a central octahedrally coordinated MnIIIcation, with two bidentate Schiff base ligands occupying the equatorial positions and two dimethyl sulfoxide (DMSO) ligands occupying the axial positions. There are two independant cations in the asymmetric unit, with the MnIIIatoms of both cations being positioned on crystallographic centers of inversion. The perchlorate anion is disordered over two equivalent conformations, with occupancies of 0.744 (3) and 0.226 (3). In addition, there is a methanol solvent molecule in the crystal lattice that is too close to the minor component of the perchlorate anion to be present simultaneously and thus it was refined to have the same occupancy as the major component of this anion. There is a Jahn–Teller distortion which results in Mn—ODMSOaxial bond lengths of 2.2365 (12) and 2.2368 (12) Å in the two cations. In the crystal, intermolecular π–π stacking between the non-coordinating pyridine rings of each cation is observed. This π–π stacking, along with extensive O—H...O hydrogen bonding and C—H...O interactions, link the components into a complex three-dimensional array.


1992 ◽  
Vol 47 (5) ◽  
pp. 685-692 ◽  
Author(s):  
Matthias Welsch ◽  
Dietrich Babel

The monoclinic weberites Na2CoFeF7 (a = 1262.2(10), b = 736.0(4), c = 2451.6(20) pm, β = 99.71(5)°) and a second modification of Na2CuFeF7 (a = 1244.4(2), b = 734.3(1), c = 2467.2(5) pm, β = 99.27(3)°), crystallize isotypically in space group C 2/c, Ζ = 16. The structure is an intermediate type between orthorhombic and trigonal weberites, characterized by pairs ofparallel chains of octahedra [MF4F2/2]3- (M = Co, Cu) which run in turn along [110] and [110]. The average distances are Fe-F = 192 pm in the [FeF63- octahedra of both compounds. Considerable splitting of distances occurs in the [CoF6- octahedra (av. Co-F = 201 pm), and by Jahn-Teller distortion even more in those of [CuFJ4- (av. Cu-F = 199 pm). One of the copper surroundings is (pseudo)tetragonally elongated (av. 209/194 pm), the other exhibits an unusual splitting into three long and three short bonds (av. 204/193 pm) in meridional positions. Some structural relations are discussed.


2006 ◽  
Vol 62 (5) ◽  
pp. m952-m953 ◽  
Author(s):  
Yang Qu ◽  
Jian-Jun Peng

In the title compound, [Cu(C7H4NO4)2(NH3)4], the Cu atom is six-coordinated by four ammine N and two 4-nitrobenzoate O atoms. Of the two nitrobenzoate ligands, one gives weaker coordination than the other. These Cu complexes are connected through a complex pattern of hydrogen-bonding interactions, resulting in a three-dimensional network.


1999 ◽  
Vol 52 (6) ◽  
pp. 625 ◽  
Author(s):  
Graham Smith ◽  
Colin H. L. Kennard ◽  
Karl A. Byriel

The crystal structure of Nevanide (diethylammonium p-aminobenzoate) has been determined and refined to a residual R 0·055 for 2797 observed reflections. Crystals are monoclinic, space group C 2/c, with 32 ion pairs in a cell with dimensions a 29·510(6), b 17·150(1), c 20·473(5) Å, β 115·153(9)°. The structure is made up of a network of hydrogen-bonded ions; in this network the 4-aminobenzoate anions form a primary cyclic tetramer unit in which the amine groups of two residues are linked tail to tail through hydrogen bonds to single carboxylate oxygens of the other two residues. All oxygens are then linked peripherally to layers of diethylammonium cations by strong hydrogen bonding, with all possible hydrogen bonding sites utilized, giving a three-dimensional network array.


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