Crystal Structure of Calcium Picrate Pentahydrate: A New Eight-Coordinate Stereochemistry for [M(bidentate)2(unidentate)4]

1979 ◽  
Vol 32 (2) ◽  
pp. 301 ◽  
Author(s):  
V Diakiw ◽  
TW Hambley ◽  
DL Kepert ◽  
CL Raston ◽  
AH White

The crystal structure of the title compound, Ca(C6H2N307)2,5H2O, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.049 for 1513 'observed' reflections. Crystals are orthorhombic, Pmab, a 24.169(6), b l0.292(7), c 8.554(2) �, Z 4. The stereochemistry about the calcium has not been observed previously for the system [M(bidentate)2- (unidentate)4]; in the present structure, the calcium is coordinated by a pair of bidentate picrate ligands and the four water molecules in an array in which three of the water molecules occupy a triangular face of a square antiprism, the overall array having m symmetry. The remaining water molecule occupies a lattice site with no close interaction with the other species.

1980 ◽  
Vol 33 (1) ◽  
pp. 69 ◽  
Author(s):  
GJ Honan ◽  
DL Kepert ◽  
SF Lincoln ◽  
JM Patrick ◽  
AH White

The crystal structure of the title compound, [UO2{OCHN(CH2)5}4(H2O)] (ClO4)2, has been determined by single-crystal X-ray diffraction at 295 K and refined by least squares to a residual of 0.051 for 3113 'observed' reflections. Crystals are monoclinic, C2/c, a 16.945(2), b 12.711(2), c 17.304(2)Ǻ, β 107.76(1)°, Z 4. The uranyl moiety [U=O, 1.76(2)Ǻ] is five-coordinated in the equatorial plane by the water molecule [U-O, 2.436(8)Ǻ] and four organic ligands [U-O, 2.379(8), 2.396(13)Ǻ]. The angles O-U-O in the equatorial plane range from 70.3(3) to 73.6(3)°; O=U-0 range between 86.7 and 95.3°. The angle O=U=O is 177.8(3)°. The stereochemistry of seven-coordinate uranyl compounds is examined by using repulsion theory.


1991 ◽  
Vol 56 (7) ◽  
pp. 1454-1460 ◽  
Author(s):  
Jaroslav Podlaha ◽  
Jana Podlahová

The crystal structure of the title compound containing a phosphorus analogue of EDTA as the ligand was determined from single-crystal X-ray diffraction data and refined to R = 0.028 for 1 920 observed reflections. The crystals are monocyclic, space group P21/c,a = 8.6169(8), b = 16.0539(9), c = 8.2504(6)Å, β = 103.458(7)° and Z = 2. The structure is completely different from that of the nitrogen prototype, [CdEDTA]2-. It consists of double-stranded polymeric layers which are composed of metal coordination polyhedra linked by μ6-hexadentate ligands; the layers lie parallel to the bc plane and are joined along the a axis through hydrogen bonding donated by water molecules. Because of steric requirements of phosphorus, the coordination polyhedron around Cd is greatly distorted and can best be described as a 5 + 3 type. One P atom, two oxygen atoms from two monodentate carboxylate groups and two water molecules form an approximate trigonal bipyramid and further three more remote carboxylate oxygens complete the arrangement, resulting in an O7P distorted bicapped trigonal prism.


1979 ◽  
Vol 32 (12) ◽  
pp. 2757 ◽  
Author(s):  
CL Raston ◽  
B Walter ◽  
AH White

The title compound, [C5H6N]+ [Cu2(SCN)3]-, has been prepared and its crystal structure determined by single-crystal X-ray diffraction at 295(1) K. Crystals are monoclinic, Cc, a 11.238(7), b 11.644(4), c 10.020(4)Ǻ, β 102.67(3)°, Z 4, the structure being refined to a residual of 0.037 for the 960 'observed' reflections. The structure comprises a three-dimensional network of copper(I) atoms linked by bridging thiocyanate groups, the pyridinium counterions occupying sites in the network cavities. Both copper atoms are four-coordinate, one having an environment of one nitrogen atom [Cu-N, 1.926(9)Ǻ] and three sulfur atoms [Cu-S, 2.319(3), 2.421(3), 2.448(3)Ǻ], while the other is coordinated by two atoms of each type [Cu-N, 1.935(9), 1.947(10); Cu-S, 2.430(3), 2.493(4) Ǻ].


1978 ◽  
Vol 31 (1) ◽  
pp. 47 ◽  
Author(s):  
ES Kucharski ◽  
BW Skelton ◽  
AH White

The crystal structure of the title compound, [Co(terpy)(CO3)(OH)],4H2O, has been determined at 295 K by single-crystal X-ray diffraction and the use of diffractometer data, and refined by least squares to a residual of 0.075 for 1354 ?observed? reflections. Crystals are triclinic, Pī, a 11.407(6), b 10.566(6), c 8.445(4) Ǻ, α 100.21(5), β 107.35(5), γ 102.18(5)°, Z2. The structure of the molecule is unusual for a 1 : 1 transition metal/terpy complex in that the other ligating atoms are non-halide and the complex six-coordinate. The remaining three coordination positions about the metal are occupied by the bidentate carbonate (Co-O 1.918(9), 1.918(8) Ǻ) and the hydroxide ion (Co-O 1.894(10) Ǻ). The Co-N distances are appreciably shorter than those observed in other terpy systems (Co-N(central) 1.848(8); Co-N(outer) 1.946(9), 1.952(9) Ǻ).


1978 ◽  
Vol 31 (11) ◽  
pp. 2545 ◽  
Author(s):  
BN Figgis ◽  
CL Raston ◽  
RP Sharma ◽  
AH White

The crystal structure of the title compound, [Mn(C5H4NCO2)3],H2O, has been determined by single-crystal X-ray diffraction at 295 K and refined by least squares to a residual of 0.053 for 2234 'observed' reflections. Crystals are monoclinic, C2/c, a 30.50(2), b 8.387(8), c 13.903(7) Ǻ, β 94.15(3)°, Z 8. The geometry of the manganese environment displays a pseudo-tetragonal distortion, the axial atoms being nitrogen (Mn-N 2.254(6), 2.217(6) Ǻ). The equatorial atoms are at distances Mn-N 2.059(5) Ǻ, Mn-O 1.891(5), 1.908(5), 1.942(5) Ǻ, the latter being trans to the nitrogen. The occupancy of the water molecule site is 0.54(1).


1978 ◽  
Vol 31 (10) ◽  
pp. 2207 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
G Winter

The crystal structure of the title compound (NEt4) [Bi(S2COEt)4] has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.051 for 1560 'observed' reflections. Crystals are monoclinic, P21, a 10.947(2), b 16.334(4), c 10.589(2)Ǻ, β 116.04(2)°, Z 2. The bismuth coordination stereochemistry is dodecahedral, Bi-S ranging from 2.803(11) to 2.972(10) Ǻ; the three longest distances occupy a triangular face in the coordination polyhedron and may indicate the presence of a stereochemically active lone pair.


1980 ◽  
Vol 33 (2) ◽  
pp. 431 ◽  
Author(s):  
A Farrand ◽  
AK Gregson ◽  
BW Skelton ◽  
AH White

The crystal structure of the title compound, K2Cu(CO3)2, has been determined by single-crystal X-ray diffraction at 295(1) K, and refined by least squares to a residual of 0.027 for 1441 'observed' reflections. Crystals are orthorhombic, space group Fdd2, a 11.425(3), b 17.658(4), c 6.154(2) A, Z 8. The structure comprises potassium cations embedded in an infinite three-dimensional polymeric anionic array of square-planar coordinated copper atoms with bridging carbonate groups [Cu-O 1.934(2), 1.936(2) Ǻ]. Within the latter, the non- coordinating oxygen-carbon bond is shorter [1.259(3) Ǻ] than the other two [1.303(3), 1.307(2) Ǻ] and the O-C-O angle opposite it is correspondingly reduced to 117.1(2)°. The CO3 plane lies at 83.9° to the CuO4 'plane'.


1984 ◽  
Vol 37 (7) ◽  
pp. 1405 ◽  
Author(s):  
PC Healy ◽  
JM Patrick ◽  
AH White

The crystal structure of the title compound, [(OH2)3(phen)FeOFe(phen)(OH2)3](NO3)4.(H2O)(phen = 1,10-phenanthroline), has been determined by single-crystal X-ray diffraction methods at 295 K, being refined by least-squares methods to a residual of 0.059 for 3467 independent 'observed'reflections. Crystals are monoclinic, P 21/c, a 18.202(6), b 9.771(4), c 19.459(7) �, β 94.46(3)�, Z = 4. Two of the four anions are disordered. Within the cation, the geometry is typical of high-spin iron(III). O(bridge)-Fe are 1.765(4), 1.784(4) �, with Fe-O-Fe 162.0(3)�. The three water molecules in the coordination sphere of each iron atom are fac; those trans to the O-Fe bond have long Fe-(OH2) distances [2.154(5), 2.125(5) �] compared to those trans to the phenanthroline chelates [2.028(5)-2.037(5) �]. Fe-N range from 2.143(6) to 2.166(6) �.


2004 ◽  
Vol 68 (5) ◽  
pp. 757-767 ◽  
Author(s):  
T. Mihajlović ◽  
H. Effenberger

AbstractHydrothermal synthesis produced the new compound SrCo2(AsO4)(AsO3OH)(OH)(H2O). The compound belongs to the tsumcorite group (natural and synthetic compounds with the general formula M(1)M(2)2(XO4)2(H2O,OH)2; M(1)1+,2+,3+ = Na, K, Rb, Ag, NH4, Ca, Pb, Bi, Tl; M(2)2+,3+ = Al, Mn3+, Fe3+, Co, Ni, Cu, Zn; and X5+,6+ = P, As, V, S, Se, Mo). It represents (1) the first Sr member, (2) the until now unknown [7]-coordination for the M(1) position, (3) the first proof of (partially) protonated arsenate groups in this group of compounds, and (4) a new structure variant.The crystal structure of the title compound was determined using single-crystal X-ray diffraction data. The compound is monoclinic, space group P21/a, with a = 9.139(2), b = 12.829(3), c = 7.522(2) Å, β = 114.33(3)°, V = 803.6(3) Å3, Z = 4 [wR2 = 0.065 for 3530 unique reflections]. The hydrogen atoms were located experimentally.


2017 ◽  
Vol 74 (1) ◽  
pp. 108-112 ◽  
Author(s):  
Urszula Anna Budniak ◽  
Paulina Maria Dominiak

Isoguanine, an analogue of guanine, is of intrinsic interest as a noncanonical nucleobase. The crystal structure of isoguaninium chloride (systematic name: 6-amino-2-oxo-1H,7H-purin-3-ium chloride), C5H6N5O+·Cl−, has been determined by single-crystal X-ray diffraction. Structure analysis was supported by electrostatic interaction energy (E es) calculations based on charge density reconstructed with the UBDB databank. In the structure, two kinds of molecular tapes are observed, one parallel to (010) and the other parallel to (50\overline{4}). The tapes are formed by dimers of isoguaninium cations interacting with chloride anions. E es analysis indicates that cations in one kind of tape are oriented so as to minimize repulsive electrostatic interactions.


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