More insight into the crystal structure of [Co(H 2 O) 4 (4-nba) 2 ]·2H 2 O (4-nba=para-nitrobenzoate): an unprecedented hydrogen bonded Supramolecular network (original) (raw)
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Crystal and molecular structure of di(para-nitrobenzoato)diaquolead
Journal of Structural Chemistry, 1990
In previous work [1], we synthesized a complex of lead p-aminobenzoate. The results of a structural analysis showed that p-aminobenzoic acid reacts with lead to form a coordination polymer. The effect of the substituent at the para position relative to the carboxyl group of the benzoate anion is very significant. The nitro group is more "flexible" in comparison with the amino group. It was of interest to study the dependence of the structure formation on the nature of the substituent in the benzoate anion. For this purpose, we studied the structure of di(para-nitrobenzoata)diaquolead. Lead nitrobenzoate, [Pb(p-NO2C6H4CO2)2.2H20] was synthesized by the reaction of aqueous solutions of Pb(NO3) 2 and sodium para-nitrobenzoate in 1:2 stoichiometric ratio. The mixture of these solutions was stirred for 20 min on a steam bath, cooled, and filtered. Colorless platelets precipitated upon standing for several days at room temperature. The x-ray diffraction structural analysis was carried out on a Syntex P21 automatic diffractometer with 6/20 scanning, 2ema x = 60 ~ The unit cell parameters of the triclinic crystals are as follows: a =__7.22(1), b = I 1.60(2), c = 6.98(3) A, a = 114.48(1), fl = 111.69(1), 7 = 65.06(1)*, V-463.78/k z, Z = 1, space group P1. A total of 1199 independent reflections were measured. A total of 1188 reflections with F 2 ~ 2a were used in the structural calculations. Absorption was not taken into account. All the calculations were carried out on an ES-1022 computer using the SHELX-76 program [2]. The structure was solved by the heavy atom method. The coordinates of the lead atom were determined from the three-dimensional Patterson map. The R value was 0.15 after anisotropic refinement cycles. The three-dimensional electron density difference map revealed the positions of all the nonhydrogen atoms of the complex. Three refinement cycles (anisotropic approximation for Pb, isotropic approximation for oxygen and carbon atoms) reduced R to 0.10. The basis atoms are given in Table 1. The projection of the structure of [Pb(p-NO2C6H4CO2)2.2H20] on the (100) plane is shown in Fig. 1. The bond lengths and bond angles are given in Table 2. The crystal structure of this complex is insular. The lead atom is in a special position. The lead atom has octahedral coordination. The apices of the octahedron are occupied by four carboxyl group oxygen atoms and two water molecules. The centrosymmetric carboxyl groups form a chelate with the metal atom (Pb-O(I), 2.48(6); Pb-O(2), 2.71(3) A). The Pb-O bond lengths in the structure are greater than the analogous values for the para-aminobenzoate complex (Pb-O(3), 2.39(3); Pb-O(4), 2.51(3) A) [1]. The Pb-O w bond length involving the centrosymmetric water molecule is 2.55(7) A. This value is in accord with the corresponding lengths 2.33-2.55 A in PbC204.3H20 [3]. According to the literature data, the Pb-OH 2 bond lengths lie in the range from 2.38 to 3.30 A. The analogous bond lengths found in the present structure approach the lower limit of this range. Thus, the coordination number of lead is expanded to six. Table 2 shows that the coordination polyhedron of lead is highly distorted. The distortions of the coordination polyhedron may be explained by the formation of a chelate ring of the R-CO2-groups. The sum of the intracyclic angles in the PbO(I)C(I)O(2) chelate ring (359.8 ~ differs only slightly from the ideal value of 360*. This indicates a planar structure of the chelate ring. The lengths of the CO bonds in the coordinated nitrobenzoate anion are 1.26(3) and 1.29(3) A and are identical to the CO bond lengths in Pb(p-HOC6H4CO2)2-H20 [4] (1.26(7) and 1.29(4) A) although the dentation of the carboxyl groups differs (a-4s-a). A marked increase is noted for the O-CO bond angle (136.0(5)~ Such increases and decreases in O-C-Obond angles are encountered in all aromatic lead carboxylates studied in our laboratory [1, 4-6]. The mean CC bond length in the benzene ring is 1.39(1) A, while the mean bond angle is 118.5". These values coincide with the corresponding values in analogous complexes and indicate a planar structure of the benzene ring.
2020
Dissolution of a fine powder obtained by mechanochemical grinding of cobaltous carbonate with 4-nitrobenzoic acid (4-nbaH) in hot dimethylsulfoxide (DMSO) followed by slow evaporation of the solvent resulted in the formation of cis-diaquabis(dimethylsulfoxide)4-nitrobenzoatocobalt(II) 4-nitrobenzoate 1 in good yield. The title compound [Co(H2O)2(DMSO)2(4-nba)]4-nba 1 crystallizes in the centrosymmetric monoclinic P21/c space group. The structure of 1 consists of two crystallographically independent Co(II) ions. Each unique cobalt exhibits octahedral geometry and is bonded to a pair of terminal aqua ligands situated cis to each other and a bidentate 4-nba ligand which form the square base of the octahedron. A pair of DMSO ligands disposed trans to each other complete the hexa coordination around the central metal. The [Co(H2O)2(DMSO)2 (4-nba)] cations and the 4-nba anions are interlinked with the aid of several weak H-bonding interactions. A comparative study of several 4-nitrobenzoa...
Crystal structure of 4-formyl-2-nitrophenyl 4-chloro-2-nitrobenzoate
Acta Crystallographica Section E Crystallographic Communications, 2015
In the title compound, C14H7ClN2O7, the central ester moiety is essentially planar, with an r.m.s. deviation of 0.0113 Å. The ester group is twisted away from the chloro- and formyl-substituted rings by 84.60 (9) and 88.55 (9)°, respectively. The crystal packing shows intermolecular C—H...O interactions. These interactions generateR22(20) andR44(22) edge-fused rings parallel to (20-2).
Acta crystallographica. Section C, Crystal structure communications, 2005
Anilinium 2-carboxy-4-nitrobenzoate, C6H8N+.C8H4NO6-, (I), 4-chloroanilinium 2-carboxy-4-nitrobenzoate, C6H7ClN+.C8H4NO6-, (II), 4-bromoanilinium 2-carboxy-4-nitrobenzoate, C6H7BrN+.C8H4NO6-, (III), and 4-iodoanilinium 2-carboxy-4-nitrobenzoate, C6H7IN+.C8H4NO6-, (IV), are approximately isostructural. In each compound, the ions are linked into complex sheets by a combination of O-H...O and N-H...O hydrogen bonds. Within the sheets, two distinct one-dimensional substructures can be identified, viz. a chain of edge-fused R(3)3(13) rings and a double helix of simple C(2)2(9) chains. In (I) and (IV), the sheets are linked by a C-H...O(nitro) hydrogen bond and a two-centre C-I...O(nitro) interaction, respectively, but the corresponding C-Cl...O and C-Br...O contact distances in (II) and (III) are not significantly shorter than the sum of the van der Waals radii.
Hydrogen-bonding network in the organic salts of 4-nitrobenzoic acid
Central European Journal of Chemistry, 2006
The crystal structures of six novel salts of 4-nitrobenzoic acid — namely, 2-hydroxyethylammonium 4-nitrobenzoate (I), 2-hydroxypropylammonium 4-nitrobenzoate (II), 1-(hydroxymethyl)propylammonium 4-nitrobenzoate (III), 3-hydroxypropylammonium 4-nitrobenzoate (IV), bis-(2-hydroxyethylammonium) 4-nitrobenzoate (V), morpholinium 4-nitrobenzoate (VI) — containing the same anion but different cations have been studied. The ionic forms of I-VI serve as building blocks of the supramolecular architecture, and in crystals they are held together via ionic N-H···O and O-H···O hydrogen bonds. In the crystal packing the building blocks of I-III are self-assembled via N-H...O, O-H···O and C-H...O hydrogen bonds to form the chains which are further consolidated into two-dimensional layers by the same type of interactions. In IV-VI the chain-like structures have been generated by building blocks.
First alkaline earth 2-carbamoyl-4-nitrobenzoate: Synthesis and supramolecular structure
2009
2-Carbamoyl-4-nitrobenzoic acid (2-ca-4nbaH) has been prepared by alkaline hydrolysis of 4-nitrophthalimide. Aqueous reaction of MgCO 3 with 2-ca-4nbaH results in the formation of [Mg(H 2 O) 6 ](2-ca-4nba) 2 , which crystallizes in the centrosymmetric monoclinic space group P2 1 /c with Mg(II) situated on an inversion center. The crystal structure consists of a distorted octahedral hexaaquamagnesium(II) cation and a free uncoordinated 2-ca-4nba anion. The cation and anion are involved in three varieties of H-bonding interactions, resulting in a supramolecular bilayer of 2-ca-4nba anions sandwiched between layers of [Mg(H 2 O) 6 ] 2+ cations.
The crystal structure of 4-(pyren-1-yl)butyl-4-nitrobenzoate, C27H21NO4
Zeitschrift für Kristallographie - New Crystal Structures
C27H21NO4, triclinic, P 1 ‾ Poverline1P\overline{1}Poverline1 (no. 2), a = 7.3476(2) Å, b = 7.4894(2) Å, c = 20.5137(5) Å, α = 89.33000(10)°, β = 79.7070(10)°, γ = 67.5220(10)°, V = 1024.31(5) Å3, Z = 2, R gt (F) = 0.0536, wR ref (F 2) = 0.1792, T = 296.15 K.
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