Heavy-Metal Complexes With (2-Chlorophenoxy)acetic Acid: The Crystal Structures of Polymeric Mercury(II) (2-Chlorophenoxy)acetate and the Thallium(I) (2-Chlorophenoxy)acetate(2-Chlorophenoxy)acetic Acid Adduct

1990 ◽  
Vol 43 (8) ◽  
pp. 1431 ◽  
Author(s):  
TCW Mak ◽  
WH Yip ◽  
CHL Kennard ◽  
G Smith

The crystal structures of the mercury(II) and thallium(I) complexes with (2-chlorophenoxy)acetic acid have been determined by X-ray diffraction, and refined to residual values R 0.040 and 0.060 for 1130 and 1612 observed reflections respectively. catena-[ Bis {(2- chlorophenoxy ) acetato }mercury(II)] is monoclinic, space group Cc with Z 4 in a cell of dimensions a 25.449(7), b 7.335(2), c 10.154(1) Ǻ, β 112.83(2)°. Mercury is bonded linearly to two carboxylate oxygens [Hg-O, 2.02(1), 2.04(1)Ǻ; O-Hg-O, 175.5(6)°] and forms a polymer link to a third oxygen [Hg-O, 2.60(2)Ǻ; O-Hg-O, 88.8(6), 87.6(7)°] giving triangular coordination about the mercury. The complex adduct {(2-chlorophenoxy) acetato }thallium(I)-(2-chlorophenoxy)acetic acid is monoclinic, space group C2/c with a 27.97(1), b 4.798(1), c 13.389(6) Ǻ, β 94.23(3)° and Z 4. This is an example of an ML.LH compound, having twofold rotational symmetry with the acid proton not located. The Tl -O bonds to each ligand molecule are 2.826(7)Ǻ with two longer bonds to adjacent carboxylate oxygens [3.002(7)Ǻ] completing a distorted square-planar stereochemistry about thallium. This results in a linear polymer structure.

1997 ◽  
Vol 50 (7) ◽  
pp. 741 ◽  
Author(s):  
Graham Smith ◽  
Brett A. Cloutt ◽  
Karl A. Byriel ◽  
Colin H. L. Kennard

The urea adducts with silver(I) perchlorate (2 : 1) (1) and silver(I) p-toluenesulfonate (1 : 1) (2) have been prepared and their structures determined by single-crystal X-ray diffraction methods. Crystals of adduct (1) are monoclinic, space group P21/a, with four molecules in a cell with dimensions a 7·806(2), b 15·929(2), c 7·861(3) Å, β 113·35(1)°, while (2) is also monoclinic, space group P21, with two dimer units in a cell with a 5·380(3), b 25·72(2), c 7·926(5) Å, β 94·22(3)°. Both form polymer structures which are stabilized by extensive hydrogen bonding. Adduct (1) is based upon a square planar trans-AgN2O2 repeating unit involving bonds to the two independent urea molecule with the perchlorate anion uncoordinated, while with (2), the oxygens of two urea molecules bridge two trigonal bipyramidal (AgNO4) silver centres, forming cyclic pseudo-centrosymmetric four-membered dimer repeats. The silver coordination of (2) also includes two cis-related sulfonate oxygens from bridging p-toluenesulfonate ligands, as well as a third bridging urea amine nitrogen. The result is a step-polymer ribbon structure.


1986 ◽  
Vol 39 (11) ◽  
pp. 1823 ◽  
Author(s):  
CHL Kennard ◽  
EJ Oreilly ◽  
S Schiller ◽  
G Smith ◽  
AH White

The crystal structures of 2-fluorophenoxyacetic acid ( oflpaH ) and the metal complexes aquabis (2-fluorophenoxyacetato) bis (pyridine)copper(II) (1) and tetraaquabis (2-fluorophenoxyacetato)zinc(II) dihydrate (2) have been determined by X-ray diffraction and refined to residuals R 0.036, 0.041, 0.025 for 641, 863 and 1505 observed reflections respectively. The acid crystallizes in a monoclinic cell, space group P21/c with a 6.207(2), b 19.363(8), c 6.999(2) Ǻ, β 114.81(2)� and Z 4. The molecules form planar, centrosymmetric , hydrogen-bonded cyclic dimers [O...O, 2.618(4)Ǻ]. Complex (1) is orthorhombic, space group P2cb with two molecules in a cell of dimensions a 5.621 (2), b 17.218(7), c 13.288(6)Ǻ while (2) is monoclinic, space group P21/c, a 6.597(2), b 5.279(2), c 30.079(10) Ǻ, β 94.65(3)�; with Z 2. Complex (1) has square-pyramidal geometry with the basal plane containing two trans related carboxyl oxygens [Cu-O, 1.944(4)Ǻ] and two trans related pyridine nitrogens [Cu-N, 2.030(5)Ǻ]. A water molecule occupies the apex of the square pyramid [Cu-OW, 2.199(8)Ǻ]. Complex (2) has octahedral geometry with the MO6 octahedron containing two trans related carboxyl oxygens [Zn-O, 2.122(2)Ǻ] and four water oxygens [Zn-OW, 2.069(2), 2.085(2)Ǻ]. Preliminary X-ray data also confirm that the magnesium(II) and manganese(II) complexes of 2-fluorophenoxyacetic acid are isomorphous with (2) but different from the cobalt(II) derivative.


1988 ◽  
Vol 41 (5) ◽  
pp. 683 ◽  
Author(s):  
TCW Mak ◽  
WH Yip ◽  
CHL Kennard ◽  
G Smith ◽  
EJ Oreilly

The crystal structures of perfluorophenoxyacetic acid [(2,3,4,5,6- pentafluorophenoxy )acetic acid] and its anhydrous complexes with silver(I) and mercury(I) have been determined by X-ray diffraction and refined to residuals R = 0.046, 0.042 and 0.104 for 1235, 1789 and 2750 observed reflections respectively. The acid forms the usual hydrogen- bonded cyclic dimers [O---O, 2.705(3)Ǻ] with the oxyacetic acid side- chain synclinally oriented. Crystals age triclinic, space group Pī with Z 2 in a cell of dimensions a 7.479(1), b 7.592(2), c 8.463(2)Ǻ,α 80.15(2),β 85.34(2),γ 61.31(1)Ǻ. The silver complex, [Ag2L2],(1), has crystals with a 5.992(3), b 30.22(2), c 5.277(2)Ǻ, β 106.42(5)°, space group P21/a and Z 2. The bis-carboxylato (O,O′) dimers have Ag-Ag 2.943(1)Ǻ with Ag-O, 2.203, 2.230(3)Ǻ and O-Ag-O 161.6(2)°. The complex with mercury(I), [Hg2L2]n, (2), is centrosymmetric with the usual linear O-Hg-Hg-O-bonds [Hg-Hg, 2.514(1)Ǻ; Hg-O, 2.13(1)Ǻ; O-Hg-Hg, 173.9(2)°]. Longer peripheral bonds to Hg [Hg-O, 2.63(1)Ǻ] produce a polymeric structure. Crystals of (2) are triclinic, space group Pī with Z 1 in a cell of dimensions a 5.038(1), b 5.970(1), c 15.774(6)Ǻ, α 80.77(2),β 86.42(2),γ 84.38(2)°.


1987 ◽  
Vol 40 (7) ◽  
pp. 1147 ◽  
Author(s):  
EJ Oreilly ◽  
G Smith ◽  
CHL Kennard ◽  
TCW Mak

The crystal structures of (2-formyl-6-methoxyphenoxy)acetic acid (1), diaquabis [(2-formyl-6-methoxyphenoxy) acetato ]zinc(11) (2), tetraaquabis [(2-chlorophenoxy) acetato ]zinc(11) (3), triaquabis [(2-chlorophenoxy) acetato ]cadmium(11) dihydrate (4) and lithium (2-chloro- phenoxy )acetate 1.5 hydrate (5) have been determined by X-ray diffraction. The acid (1) forms centrosymmetric hydrogen-bonded cyclic dimers [O…0, 2.677(6) �] which are non-planar. Complex (2) is six-coordinate with two waters [Zn- Ow , 1.997(2) �] and four oxygens from two asymmetric bidentate carboxyl groups [Zn-O, 2.073, 2.381(2) �] completing a skew trapezoidal bipyramidal stereochemistry. Complex (5) is also six-coordinate but is octahedral, with two trans-related unidentate carboxyl oxygens [mean Zn-O, 2.134(9) �] and four waters [mean Zn-O, 2.081(9) �]. The seven-coordinate complex (4) has crystallographic twofold rotational symmetry relating two :symmetric bidentate acid ligands [ Cd -O, 2.26, 2 48(:) �] and two waters [ Cd -O, 2.34(2) �] while the third water lies on this axis [ Cd -O, 2.27(2) �]. In contrast to the monomers (2)-(4), complex (5) is polymeric with tetrahedral lithium coordinated to one water and three carboxylate oxygens [mean Li-0, 1.95(1) �]. The essential conformation of the free acid is retained in complexes (2), (3) and (4) but in (5), it is considerably changed.


1996 ◽  
Vol 49 (12) ◽  
pp. 1301 ◽  
Author(s):  
GW Allen ◽  
ECH Ling ◽  
LV Krippner ◽  
TW Hambley

The preparation and purification of [Pt( hpip )Cl2] and [Pd( hpip )Cl2] ( hpip = homopiperazine = 1,4-diazacycloheptane) are described. Crystal structures of [Pt( hpip )Cl2] and [Pd( hpip )Cl2] have been determined by X-ray diffraction methods and refined to R values of 0.023 (932 F) and 0.023 (948 F). The crystals of [Pt( hpip )Cl2] are orthorhombic, space group Pbcm , a 7.7019(8), b 9.8080(12), c 12.1944(14) Ǻ, and those of [Pd( hpip )Cl2] are monoclinic, space group P21/m, a 6.1001(9), b 11.527(2), c 6.458(I) Ǻ, β 106.30(2)°. The seven- membered rings of the ligands in both complexes adopt boat-like conformations in which the five- membered chelate ring has an eclipsed N-C-C-N group and the six- membered chelate ring adopts a chair conformation. Molecular mechanics methods were used to investigate whether this conformation was a crystallographic artefact but it was found to be real. An alternative conformation in which the six-membered chelate ring adopts a skew-boat conformation was also investigated. It was found to be less stable than the conformation observed in the crystal structures, but to a degree that depends on whether non-bonded interactions involving the metal atom were included or not.


1997 ◽  
Vol 50 (9) ◽  
pp. 903 ◽  
Author(s):  
Trevor W. Hambley ◽  
Walter C. Taylor ◽  
Stephen Toth

Four novel norditerpenoids were isolated from a new encrusting sponge, conveniently labelled Aplysilla pallida. The structures of aplypallidenone (1), aplypallidoxone (2), aplypallidione (3) and aplypallidioxone (4) were elucidated by spectroscopic studies and the crystal structures of aplypallidenone and aplypallidoxone have been determined by X-ray diffraction methods. The structure of (1) was refined to a residual of 0·040 for 1665 independent observed reflections and the structure of (2) was refined to a residual of 0·031 for 1699 independent observed reflections. The crystals of (1) are orthorhombic, space group P212121, a 7·728(2), b 10·838(4), c 24·880(5) Å, Z 4. Those of (2) are monoclinic, space group C 2, a 23·927(7), b 6·674(2), c 14·033(3) Å, Z 4.


1985 ◽  
Vol 40 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Siegfried Pohl ◽  
Wolfgang Saak ◽  
Bernt Krebs

Abstract The compounds [(C6H5)4As]2 TeCl4 (1), [(C2H5)4 N]2 TeBr4 · CH3CN (2), and [(C2H5)4N]2TeI4 (3) were prepared by the reaction of Te, X2 , and excess (C2H5)4NX (X = Br, I) in acetonitrile solution or by heating of [(C6H5)4 As]2TeCl6 , Te, and (C6H5)4 ASCl for several hours in the same solvent.The structures of 1-3 were determined from single crystal X-ray data.1 crystallizes in the monoclinic space group P21/n with a = 1061.8(2), b = 1614.2(3), c = 1341.7(3) pm, β = 94.21° and Z = 2; 2: tetragonal, P4/mmm, a = 1039.7(2), c = 690.5(1), Z = 1; 3: tetragonal, I4/mmm, a = 1061.7(2), c = 1342.8(4), Z = 2. In 1-3 Te(II) exhibits a square planar coordination. The Te -CI, Te -Br, and Te-I bond lengths were found to be 260.7 (mean), 275.3, and 298.5 pm, respectively.


Author(s):  
Michel Fleck ◽  
Ekkehart Tillmanns ◽  
Ladislav Bohatý ◽  
Peter Held

AbstractThe crystal structures of eight different L-malates have been determined and refined from single-crystal X-ray diffraction data. The compounds are the monoclinic (space groupIn addition, for all the compounds, powder diffraction data were collected, analysed and submitted to the powder diffraction file (PDF).


1995 ◽  
Vol 73 (9) ◽  
pp. 1520-1525
Author(s):  
Luciano Antolini ◽  
Ugo Folli ◽  
Dario Iarossi ◽  
Adele Mucci ◽  
Silvia Sbardellati ◽  
...  

The crystal structures of the title compounds were determined by single crystal X-ray diffraction techniques. The molecule of the Z isomer, which crystallizes in the monoclinic space group C2/c with Z = 4 in a cell of dimensions a = 14.891 (2), b = 10.780(2), c = 8.769(1) Å, β = 97.47(2)°, V = 1395.7(7) Å3 has crystallographic twofold symmetry. The E form crystallizes in the orthorhombic space group Pbca with a = 11.730(1), b = 6.932(1), c = 16.841(1) Å, V = 1369.4(2) Å3 and Z = 4. Its molecules have crystallographically dictated [Formula: see text] symmetry. In both isomers the phenyl rings are roughly perpendicular to the average ethylene plane. The atoms characterizing this plane show significant deviations from planarity in the Z isomer. Marked bond-angle distortions at the ethene carbons of both structures are observed. The 1H and 13C NMR spectra of the compounds were measured and, particularly in the case of the 1H chemical shifts, fall into two quite separate spectral regions. At low temperature, two conformational isomers, those with different relative orientation of the C—Cl bonds of the phenyl rings, are observed in the spectrum of each compound. Keywords: chlorostilbenes, overcrowded molecules. X-ray structure, conformations, NMR spectroscopy.


1995 ◽  
Vol 50 (5) ◽  
pp. 772-780 ◽  
Author(s):  
J. Baurmeister ◽  
A. Franken ◽  
W. Preetz

Abstract By treatment of protonated monoalkyl-closo-hexaborates [B6H6R]-. R = CH3, C2H5, n-C3H7, i-C3H7 in aqueous alkaline solution with [As(C6H5)4]Cl the yellow orange deprotonated tetraphenylarsonium salts are precipitated, which react with methyl iodide or ethyl iodide to give dialkylated and protonated B6-compounds. The cisltrans isomers formed in a 1:1 ratio have been separated by ion exchange chromatography on diethylam inoethyl cellulose. Repeated deprotonation and reaction with methyl iodide affords mer-[B6H4 (CH3)3]-. The crystal structures of cis-[P(C6H5)4][B6H5(CH3)2] (I), trans-[P(C6H5)4][B6H5(CH3)2] (II) and mer-[P(C6H5)4][B6H4(CH3)3](III) have been determined by single crystal X-ray diffraction analyses; I and II are monoclinic, space group P2/n, I with a = 11.8690(5), b = 7.2575(7), c = 15.8689(3) Å , β = 111.454(17)°; II with a = 13.2853(7), b = 7.4608(8), c = 13.3549(11), β = 93.5(11); III is tetragonal, space group P4/n with a = 13.363(2), c = 7.5051(13). The three methyl substituents are statistically distributed over four equatorial positions of the B6 cage. The 11B NMR spectra of the di- and trialkylated com pounds exhibit shifts of ipso-B atoms to lower, of antipodal-B atoms to higher field compared with [B6H7]-. The IR and Raman spectra of the di- and trimethyl derivatives are similar to those of monom ethylhexaborate.


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