Metal Phenoxyalkanoic Acid Interactions. XXV. The Crystal Structures of (2-Formyl-6-Methoxyphenoxy)Acetic Acid and Its Zinc(II) Complex and the Lithium, Zinc(II) and Cadmium(II) Complexes of (2-Chlorophenoxy)Acetic Acid

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.

1991 ◽  
Vol 46 (5) ◽  
pp. 566-572 ◽  
Author(s):  
Axel Gudat ◽  
Peter Höhn ◽  
Rüdiger Kniep ◽  
Albrecht Rabenau

The isotypic ternary compounds Ba3[MoN4] and Ba3[WN4] were prepared by reaction of the transition metals with barium (Ba3N2, resp.) under nitrogen. The crystal structures were determined by single crystal X-ray diffraction: Ba3[MoN4] (Ba3[WN4]): Pbca; Z = 8; a = 1083.9(3) pm (1091.8(3) pm), b = 1030.3(3) pm (1037.5(3) pm), c = 1202.9(3) pm (1209.2(4) pm). The structures contain isolated tetrahedral anions [MN4]6- (M = Mo, W) which are arranged in form of slightly distorted hexagonal layers and which are stacked along [010] with the sequence (···AB···). Two of the three Ba atoms are situated between, the third one is placed within the layers of [MN4]-groups. In this way the structures can be derived from the Na3As structure type.


1999 ◽  
Vol 52 (7) ◽  
pp. 695 ◽  
Author(s):  
Graham Smith ◽  
Catherine J. Cooper ◽  
Veena Chauhan ◽  
Daniel E. Lynch ◽  
Simon Parsons ◽  
...  

Six molecular complexes containing the herbicidally active (2,4-dichlorophenoxy)acetic acid (2,4-d) and (2,4,5-trichlorophenoxy)acetic acid (2,4,5-t) have been prepared and studied by using single-crystal X-ray diffraction techniques. These adduct structures are 2,4-d with 4,4′-dipyridine (2 : 1 complex), and 2,4,5-t with respectively 5-nitroquinoline (1 : 1), 4,4′-dipyridine (2 : 1), 2-amino-2-thiazoline (1 : 1), 2-aminobenzothiazole (1 : 1) and 2-amino-5-ethyl-1,3,4-thiadiazole (1 : 1). The conformations of the phenoxyacetic acid molecules were found to be either synclinal (in three cases) or antiperiplanar (in the other three cases). A general review is also made about the conformational aspects of previously reported adducts of phenoxyacetic acid derivatives and how they compare to their free acid structures.


1985 ◽  
Vol 38 (9) ◽  
pp. 1381 ◽  
Author(s):  
CHL Kennard ◽  
EJ O'Reilly ◽  
G Smith ◽  
TCW Mak

The crystal structures of 2-formylphenoxyacetic acid ( ofpaH ), tetraaquabis (2-formylphenoxyacetato)-cobalt(II) (1) and tetraaquabis (2- formylphenoxyacetato )zinc(II) (2) have been determined by X-ray diffraction and refined to residuals R 0.039, 0.058 and 0.045 for 1197, 1178 and 1230 observed reflections respectively. 2-Formylphenoxyacetic acid crystallizes in a monoclinic cell, space group P21/n with a 8.066(2), b 7.375(1), c 14.206(2) Ǻ, β 98.12(1)° and Z 4. The planar molecules form unusual hydrogen-bonded chain polymers (O…O 2.694(3)Ǻ] linked through the carboxyl groups. The complexes (1) and (2) are isomorphous, the comparative cells being a 5.036(1), b 13.463(3), c 15.083(4) Ǻ, β 96.88(2)° for (1), and a 5.044(1), b 13.481(3), c 15.055(4) Ǻ, β 96.95(2)° for (2), with Z 2 and space group P21. The complexes have four waters and two trans-related carboxyl oxygens [mean M-O distances 2.129(5) and 2.117(3) Ǻ respectively] completing almost regular octahedral stereochemistries . The nickel(II) complex [Ni( ofpa )(H2O)4] is probably not isostructural with (1) and (2), and the copper(II) complex is also different, with formula [Cu( ofpa )2(H2O)2].


1995 ◽  
Vol 48 (4) ◽  
pp. 869 ◽  
Author(s):  
G Smith ◽  
EJ Oreilly ◽  
SA See ◽  
KA Byriel ◽  
CHL Kennard

The ring-substituted phenoxyacetic acid (2-benzoyl-5-methoxyphenoxy)acetic acid (HL) (3) and its complex adduct dimer (4) with sodium, [Na2(L)2(HL)2].2HL, have been synthesized and their structures determined by X-ray diffraction. The acid (3) does not have the usual cyclic hydrogen-bonded dimer association, but instead has three-centre intramolecular hydrogen bonding between the carboxyl proton and both the ether and keto oxygens [O---O, 2.602(3), 2.711(3) Ǻ respectively]. Each sodium in the centrosymmetric complex dimer (4) is seven-coordinate [Na-O, 2.313(5)-2.612(5) Ǻ], involving the 'inner' three oxygens of both a protonated and an ionic ligand molecule. In addition, one of these carboxyl oxygens forms a bridge to the inversion-related sodium, while the uncoordinated carboxyl oxygen is hydrogen-bonded to a protonated carboxy group [O---O, 2.464(8) Ǻ]. The molecules of the lattice acid have only one hydrogen-bonded association with the second uncoordinated carboxy group in the dimer [O---O, 2.513(7) Ǻ].


1992 ◽  
Vol 45 (6) ◽  
pp. 969 ◽  
Author(s):  
KA Byriel ◽  
CHL Kennard ◽  
DE Lynch ◽  
G Smith ◽  
JG Thompson

The cocrystal adducts of a number of carboxylic acids with organic heterocyclic bases have been prepared, and their structures and intermolecular interactions interpreted through X-ray diffraction and infrared spectroscopic techniques. The crystal structures of three of these compounds, the 1 : 1 adducts [{(2,4-dich1orophenoxy)acetic acid)(3-hydroxypyridine)] (1), [(2,4,6-trinitrobenzoie acid)(2-aminopyrimidine)] (2), and [(4-nitrobenzoic acid)(3-amino- 1,2,4-trimole)] (3), have been determined by single-crystal X-ray diffraction and refined to residuals R 0.026, 0.033 and 0.040 for 1814, 1531 and 727 observed reflections, respectively.


1991 ◽  
Vol 44 (6) ◽  
pp. 809 ◽  
Author(s):  
DE Lynch ◽  
G Smith ◽  
KA Byriel ◽  
CHL Kennard

Three molecular cocrystal adducts of the plant hormone indole-3-acetic acid ( iaa ) have been prepared and their structures determined by X-ray diffraction. They are indole-3-acetic acid-bis [pyridin-2(1H)-one] (1), indole-3-acetic acid-3,5-dinitrobenzoic acid (2) and indole-3-acetic acid-1,3,5-trinitrobenzene (3). Complexes (2) and (3), which may be prepared in a solid-state reaction, are orange and are structurally similar, having significant π-π indole -benzene ring interactions. However, the colourless complex (1) shows no π-π ring interactions. In complex (2), the 3,5-dinitrobenzoic acid molecules form hydrogen-bonded cyclic dimers (O…O, 2.64 Ǻ), while in (3) the indole-3-acetic acid molecules form dimers (O…O, 2.66 Ǻ). This feature contrasts with the structure of adduct (1) in which the pyridin-2(1H)-one molecules exist as dimers [N…O, 2.79, 2.74 Ǻ] analogous to those found in the parent compound.


1998 ◽  
Vol 53 (4) ◽  
pp. 448-458 ◽  
Author(s):  
Andreas Böhm ◽  
Kurt Polborn ◽  
Karlheinz Sünkel ◽  
Wolfgang Beck

Abstract N,N-Dimethyl-C-phenylglycinemethylester reacts with Pd(OAc)2 in acetic acid to give the orthopalladated, acetato bridged complex 1. Treatment of 1 with sodium halide affords the chloro, bromo, and iodo bridged compounds [Me2NC(H)(CO2Me)C6H4PdX]2 (2a -c) (X = halide). From 2a and 1,1′-bis(diphenylphosphino)ferrocene the phosphine bridged trinuclear complex 3 is obtained. Substitution of the amine ligand of 2a by the phosphino group is observed for the reaction of 2a with Ph2PC(Me)C(Me)PPh2. Insertion of 2,6-dimethyl-phenylisocyanide, CO, alkyl-vinyl-ketones, and diphenylacetylene into the Pd-C bond o f 2a -c provides the orthosubstituted organic and organometallic derivatives of phenylglycine 6a -c, 7, 8a -b and 9a -c. The crystal structures of 1, 4a, 6a, 7 and 9a were determined by X-ray diffraction.


1992 ◽  
Vol 45 (7) ◽  
pp. 1101 ◽  
Author(s):  
G Smith ◽  
DE Lynch ◽  
DS Sagatys ◽  
CHL Kennard ◽  
GF Katekar

The crystal structures of four analogues of the auxin herbicide series, including inactive examples, have been determined by X-ray diffraction methods. The compounds (2-isopropy1phenoxy)acetic acid (1), (4-fluorophenoxy)acetic acid (2) and (2,4-dichloro-5-fluorophenoxy)acetic acid (3) are from the phenoxyalkanoic acid series while (indol-3-ylthio)acetic acid (4) is the sulfur analogue of the natural plant hormone indole-3-acetic acid. All examples exist as hydrogen-bonded cyclic dimers [O…O, 2.640(7), 2.62(1), 2.637(4) and 2.665(4) � for (1)-(4), respectively]. Compounds (1) and (2) are essentially planar while compounds (3) and (4) have side chains anticlinally related to the ring systems, similar to (2,4-dich1orophenoxy)acetic acid and to indole-3-acetic acid.


2001 ◽  
Vol 57 (5) ◽  
pp. 697-704 ◽  
Author(s):  
Andrzej Katrusiak

The third polymorph (denoted MH3) of maleic hydrazide (3,6-dihydroxypyridazine in the monolactim form, 6-hydroxy-3-pyridazinone, C4H4N2O2) has been studied by X-ray diffraction and shown to be monoclinic, space group P21/n. Polymorph MH3 was found as the prevailing form along with the rare triclinic polymorph MH1, space group P\bar 1, but they were obtained separately from monoclinic MH2, space group P21/c. The structure of MH1, previously studied by photographic methods, has been redetermined. Polymorph MH3 exhibits the same scheme of molecular association into hydrogen-bonded ribbons as in MH1 and MH2, but the arrangements of the aggregates and details of their supramolecular conformations are different. The accommodation of the supramolecular conformations to the requirements of close packing of the aggregates in crystal lattices, as well as the symmetries of the polymorphs, are analyzed.


1998 ◽  
Vol 51 (2) ◽  
pp. 159 ◽  
Author(s):  
Graham Smith ◽  
Daniel E. Lynch ◽  
Raymond C. Bott

A number of molecular adducts of nitro-substituted aromatic acids with Lewis bases have been prepared and characterized by infrared spectroscopy and in three cases by X-ray diffraction methods. These three compounds are the adducts of: 3,5-dinitrobenzoic acid (dnba) with N-methylaniline (nma), [(dnba)-(nma)+] (1); (4-nitrophenyl)acetic acid (4-npa) with cyclohexane-1,4-diamine (dach), [(4-npa)22-(dach)2+] (4); 5-nitrosalicylic acid (5-nsa) with 2-imidazolidone (idaz), [(5-nsa)2(idaz)] (5). Other compounds are the adducts of 3,5-dinitrobenzoic acid with 2,6-dimethylpyridine (dmp), [(dnba)(dnba)-(dmp)+] (2), and with 1-methylpyrrole-2-carboxylic acid (cmp), [(dnba)-(cmp)+] (3). Compounds (1) and (3) have 1 : 1 stoichiometry, while (2), (4) and (5) are 2 : 1 adducts. Proton transfer occurs in most examples [complex (5) is the exception].


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