Metal complexes of dicamba. II. The crystal structure of catena-m-[Diaquabis-(3,6-dichloro-2-methoxybenzoato(O,O')]-calcium(II)

1984 ◽  
Vol 37 (8) ◽  
pp. 1757 ◽  
Author(s):  
CHL Kennard ◽  
B Kerr ◽  
EJ O'Reilly ◽  
G Smith

The crystal structure of a calcium complex of the herbicide dicamba (3,6-dichloro-2-methoxybenzoic acid) has been determined by single-crystal X-ray diffraction and refined by least squares to a final residual of 0.045. [Ca(dicamba)2(H2O)2]n is orthorhombic, space group Pbcn, Z 4, with a cell a 15.844(3), b 16.833(2), c 7.751(1) �. The MO8 coordination polyhedron about the calcium ion is a distorted Archimedes antiprism which has twofold rotational symmetry. There are two waters [Ca-O, 2.414(3) �] and six carboxylate oxygens from two bidentate chelate groups [Ca-O, 2.516, 2.517(3) �] and two bridging carboxyls [2.372(3) �]. This results in an infinite linear polymer structure.

1992 ◽  
Vol 45 (6) ◽  
pp. 1021 ◽  
Author(s):  
MP Hegarty ◽  
CHL Kennard ◽  
KA Byriel ◽  
G Smith

The crystal structure of the hepatotoxic amino acid indospicine [L-6-amidino-2-aminohexanoic acid, (S)-2,7-diamino-7-iminoheptanoic acid], as its hydrochloride hydrate, has been determined by X-ray diffraction and refined to a residual R 0.036 for 845 observed reflections collected at 173 K. Crystals are orthorhombic, space group P 22121 with 8 molecules in a cell of dimensions a 5.1541(4), b 14.083(1), c 31.781(3) � . The structure is consistent with the one previously derived from chemical data but with the presence of a terminal amidinium ion and an α-amino acid zwitterion pair. The two independent molecules in the asymmetric unit are conformationally different and form a head-to-tail packing motif linked by NH(amidino)…O(carboxyl) hydrogenbonds (N…O,2.80, 2.85 � ). The structure also features extensive hydrogen bonding involving the water of solvation.


1987 ◽  
Vol 40 (7) ◽  
pp. 1161 ◽  
Author(s):  
WH Chan ◽  
TCW Mak ◽  
WH Yip ◽  
CHL Kennard ◽  
G Smith ◽  
...  

Metal complexes of two (phenylthio) alkanoic acids have been prepared and their structures determined by X-ray diffraction. catena-[( Phenylthio ) ethanoatosilver (1)] (1) forms crystals which are orthorhombic, space group Pccn, Z 8 and a 26.772(8), b 10.479(3) c 6.007(1) �. The polymer structure consists of a distorted trigonal pyramidal AgO3S repeating unit with coordination in the trigonal plane by a bidentate chelate thioethanoate group [Ag-O, 2.508(3); Ag-S, 2.513(2) �]. The third position in the plane and the axial position are occupied by bridging carboxylate oxygens [Ag-0, 2.454(3), 2.230(4) �], giving the two-dimensional structure. Complex (2) is a tetracarboxylate bridged dimer of the copper(11) ethanoate hydrate type, with a Cu-Cu separation of 2.624(2) � and Cu-OH2 (axial) distances of 2.155(7) and 2.182(6) �. Crystals are triclinic, space group PI with two dimers in a cell of dimensions a 7.340(2), b 14.863(5), c 22.963(8) �; α 104.33(2), β98.18(2), γ 102.18(2)�. Final residuals for (1) and (2) were 0.045 and 0.051 for 1688 and 3467 observed reflections respectively.


2017 ◽  
Vol 72 (12) ◽  
pp. 983-988 ◽  
Author(s):  
Martin K. Schmitt ◽  
Hubert Huppertz

Abstractβ-Y(BO2)3 was synthesized in a Walker-type multianvil module at 5.9 GPa/1000°C. The crystal structure has been elucidated through single-crystal X-ray diffraction. β-Y(BO2)3 crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a=15.886(2), b=7.3860(6), and c=12.2119(9) Å. Its crystal structure will be discussed in the context of the isotypic lanthanide borates β-Ln(BO2)3 (Ln=Nd, Sm, Gd–Lu).


1979 ◽  
Vol 57 (1) ◽  
pp. 57-61 ◽  
Author(s):  
R. Melanson ◽  
F. D. Rochon

The crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2 has been determined by X-ray diffraction. The crystals are orthorhombic, space group P212121, with a = 12.486(6), b = 13.444(7), c = 14.678(11) Å, and Z = 4. The structure was refined by block-diagonal least-squares analysis to a conventional R factor of 0.050 and a weighted Rw = 0.045.The coordination around the platinum atom is square planar. Guanosine is bonded to platinum through N(7). The purine planar ring makes an angle of 62.7° with the platinum coordination plane. The structure is stabilized by hydrogen bonding.


Author(s):  
Cristian Biagioni ◽  
Luca Bindi ◽  
Koichi Momma ◽  
Ritsuro Miyawaki ◽  
Yoshitaka Matsushita ◽  
...  

Abstract Tsugaruite was originally defined as a lead-arsenic sulfosalt from the Yunosawa mine, Aomori Prefecture, Japan. Until recently its crystal structure remained unsolved and its actual classification in the sulfosalt realm was unknown. Here the refinement of the crystal structure of tsugaruite using single-crystal X-ray diffraction data is reported. The mineral is orthorhombic, space group P2nn, with unit-cell parameters a = 8.0774(10), b = 15.1772(16), c = 38.129(4) Å, V = 4674.3(9) Å3, in agreement with previous studies. The solution of the crystal structure of this mineral revealed Cl occupying a specific position. Chlorine was thus sought and found using the electron microprobe; the average of six spot analyses gave (in wt.%): Pb 68.04, As 12.83, S 18.29, Cl 0.63, total 99.80. The empirical formula, calculated on the basis of Pb + As = 43 atoms per formula unit, is Pb28.26As14.74S49.08Cl1.52. Tsugaruite is an N = 4 plesiotypic derivative of the homologous series of Pb-Sb chloro-sulfosalts having the general formula Pb(2+2N)(Sb,Pb)(2+2N)S(2+2N)(S,Cl)(4+2N)ClN. It has a Cl/(Cl + S) atomic ratio close to that of other known Pb-Sb chloro-sulfosalts (pillaite, pellouxite) and slightly higher than that of dadsonite.


1985 ◽  
Vol 40 (12) ◽  
pp. 1631-1637 ◽  
Author(s):  
Ruth Christophersen ◽  
Paul Klingelhöfer ◽  
Ulrich Müller ◽  
Kurt Dehnicke

Abstract The pyridine complexes of cyclo-thiazeno vanadium dichloride, [VCl2(N3S2)py] and [VCl2(N3S2)(py)2] were synthesized by reactions of polymeric VCl2(N3S2) with varying amounts of pyridine in CH2Cl2. The compounds were characterized by their IR spectra as well as by their 51V NM R spectra. The crystal structure of [VCl2(N3S2)(C5H5N)] was determined by means of X-ray diffraction (1582 independent observed reflexions, R = 0.031). Crystal data: orthorhombic, space group Pnma, a = 1372, b - 2261, c - 1068 pm, Z = 12. In the lattice there are two monomeric, crystallographically independent molecules [VCl2(N3S2)(C5H5N)], which differ only slightly. The vanadium atoms have a trigonal bipyramidal coordination with the N atom of the pyridine molecule and one chlorine atom in apical positions, and with one chlorine atom and the N atoms of the cyclo-thiazeno ligand in equatorial positions. The VN bond lengths of the planar VN3S2 ring of 174 pm correspond to double bonds


1990 ◽  
Vol 43 (12) ◽  
pp. 2083 ◽  
Author(s):  
DC Craig ◽  
VJ James ◽  
JD Stevens

The crystal structure of the title compound (1) has been determined by X-ray diffraction. Crystals of (1) are orthorhombic, space group P21212 with a 11.425(1), b 24.916(1), c 5.8952(3)Ǻ, Z 4. Refinement on 1675 observed reflections measured with Cu Kα radiation converged at R 0.034. The seven- membered ring adopts a boat conformation in which the pseudo plane of symmetry passes through the ring oxygen.


1998 ◽  
Vol 51 (9) ◽  
pp. 867 ◽  
Author(s):  
Daniel E. Lynch ◽  
Lisa C. Thomas ◽  
Graham Smith ◽  
Karl A. Byriel ◽  
Colin H. L. Kennard

The crystal structure of the 1 : 1 adduct of N-methylaniline with 5-nitrofuran-2-carboxylic acid has been determined by single-crystal X-ray diffraction. Crystals are monoclinic, space group P21/c with Z 4 in a cell of dimensions a 8·467(5), b 6·106(2), c 23·95(1) Å, β 94·48(3)°. The molecules associate in a tetrameric, proton-transfer formation which has potential as a new supramolecular synthon.


1983 ◽  
Vol 36 (5) ◽  
pp. 1043 ◽  
Author(s):  
RM Carman ◽  
E Horn ◽  
CHL Kennard ◽  
G Smith ◽  
MR Snow ◽  
...  

The crystal structure of (1S,3S,4R)-1,3,8-tribromo-p-menthan-2-one has been determined from X-ray diffraction data and refined to a final residual of 0.075 for 635 'observed' reflections. Crystals are orthorhombic, of space group P212121 with four molecules in a cell of dimensions a 15.248(3), b 12.189(3), c 7.201(2) �. The analysis confirms that the molecule exists in a distorted twist-boat conformation.


1994 ◽  
Vol 49 (9) ◽  
pp. 1263-1266 ◽  
Author(s):  
A. Franken ◽  
W. Preetz

By electrochemical oxidation of [B6H6]2- in the presence of nitrite ions and of the base DBU in dichlorom ethane solution the μ-nitroso-bis(pentahydrohexaborate) [B6H5(NO)B6H5]3- ion is formed and can be isolated by ion exchange chromatography on diethylaminoethyl cellulose. The crystal structure of the Cs salt has been determined from single crystal X-ray diffraction analysis. Cs3[B6H5(NO)B6H5] is orthorhombic, space group Pnma with a = 16.2303(13), b = 12.245(6), c = 25.444(2) Å. The unit cell contains three crystallographically independent anions with nearly C2v symmetry but differently distorted B6 cages


Sign in / Sign up

Export Citation Format

Share Document