L. J. Fitzgerald

Redetermination of the structures of 1-naphthoic acid and 2-naphthoic acid

The structures of 1-naphthoic acid and 2-naphthoic acid have been investigated in order to determine the degree of disorder of the carboxylic acid groups. 1-Naphthoic acid was found to be completely ordered with C--O bond lengths of 1.214 (3) and 1.312 (3) A, and C--C--O bond angles of 124.8 (2) and 114.2 (2) degrees. 2-Naphthoic acid was found to possess a significant degree of disorder with C--O bond lengths of 1.256 (3) and 1.274 (3) A, and C--C--O bond angles of 117.7 (2) and 119.1 (2) degrees. In 2-naphthoic acid, the acid H atom was refined at two sites with 0.5 occupancy at each. Analysis of the anisotropic displacement ellipsoids of the acid O atoms for each structure demonstrated that these parameters are consistent with thermal motion of the O atoms. These results indicated that the proton, but not the O atoms, is disordered in the carboxylic acid group of 2-naphthoic acid. In each structure, the acid molecules form cyclic dimers about inversion centers, with an O...O(acceptor) distance of 2.653 (3) in 1-naphthoic acid and 2.618 (3) A in 2-naphthoic acid. The cyclic dimers form layers in each of these structures wherein lateral closest intermolecular approaches to the acid O atoms are from ring H atoms. The intermolecular O...H close approaches, together with the intramolecular close approaches, are very uniform in distance and angle of approach for the two O atoms in the 2-naphthoic acid structure.(ABSTRACT TRUNCATED AT 250 WORDS)

Structure of 1,8-naphthalenedicarboxylic acid (naphthalic acid), C12H8O4: ring geometry and hydrogen-bonding effects

C12H8O4, Mr = 216.19, orthorhombic, Pbca, a = 15.308 (2), b = 17.926 (2), c = 7.093 (2) A, V = 1946.4 (5) A3, Z = 8, Dx = 1.48 g cm-3, lambda (Mo K alpha) = 0.71073 A, mu = 1.05 cm-1, F(000) = 896, T = 296 K, R = 0.043 for 912 unique reflections having I greater than 3 sigma (I). In this structure, 1,8-naphthalenedicarboxylic acid departs significantly from planarity. While the average deviation of carbons from the best least-squares plane for the naphthalene core is 0.055 (4) A, the carboxyl carbons adopt positions +0.403 (4) and -0.350 (4) A from that plane. The carboxyl groups are twisted in the same direction with respect to that plane and make an average dihedral angle of 42.6 (3) degrees with it. The nearly equal lengths of the C--O distances within the carboxyl groups [mean value 1.267 (5) A] indicate almost complete disorder of the H atoms of these groups. Hydrogen bonding occurs in cyclic dimer fashion between two molecules related by a center of inversion. The carboxyl hydrogens appear to be subject to a symmetric double-minimum potential and to be disordered via tunneling; there is no evidence that the carboxyl oxygens are disordered. The mean carboxyl H--O acceptor distance is 1.90 (7) A.

Structure of tetrasodium 1,4,5,8-naphthalenetetracarboxylate octahydrate.

Na4[C14H4O8].8H2O, Mr = 536.3, monoclinic, P2(1)/n, a = 6.142 (1), b = 8.144 (3), c = 20.527 (4) A, beta = 93.97 (1) degrees, V = 1024.4 (5) A3, Z = 2, Dx = 1.74 g cm-3, lambda(Mo K alpha) = 0.71073 A, mu = 2.14 cm-1, F(000) = 552 T = 295 K, R = 0.039 for 1769 unique reflections having I greater than sigma I. In this structure, the title compound has an inversion center at the midpoint of the central naphthalene ring bond. The average C-C bond length in the naphthalene core is 1.41 (3) A; the average interior angle is 119.9 (1.0) degrees. The exterior angle at the central naphthalene carbon is 122.7 (3) degrees, significantly smaller than in 1.8-substituted naphthalenes. The two inequivalent carboxyl groups adopt a non-planar arrangement with respect to the naphthalene core, making an average dihedral angle of 53.8 (1) degree with it. The two inequivalent sodium ions have quite different environments. Na(1) is coordinated by six O atoms in a highly distorted octahedral arrangement with an average Na-O distance of 2.44 (10) A. Na(2) is coordinated by five O atoms in a highly distorted trigonal bipyramidal arrangement with an average Na-O distance of 2.36 (3) A. Each of the eight inequivalent water H atoms is involved in a single hydrogen bond. The average H...O (acceptor) distance is 2.00 (5) A, the average O...O (acceptor) distance is 2.85 (5) A and the average O-H...O (acceptor) angle is 165 (8) degrees for these hydrogen bonds.(ABSTRACT TRUNCATED AT 250 WORDS)

Structure of the sodium salt of 1,4,5,8-naphthalenetetracarboxylic acid 4,5-anhydride hydrate

Sodium hydrogen 1,3-dioxo-1H,3H-naphtho[1,8-cd]pyran-6,7-dicarboxylate hydrate, Na[C14H5O7].H2O, Mr = 326.2, triclinic, P1, a = 9.520 (2), b = 9.549 (3), c = 7.860 (1) A, alpha = 105.88 (2), beta = 110.29 (1), gamma = 100.89 (2) degrees, V = 611.9 (3) A3, Z = 2, Dx = 1.77 g cm-3, lambda(Mo K alpha) = 0.71073 A, mu = 1.67 cm-1, F(000) = 332, T = 295 K, R = 0.042 for 1665 unique reflections having I greater than 3 sigma I. The organic portion of this structure demonstrates near-C2 symmetry with a pseudo-twofold axis coincident with the central C-C naphthalene ring bond. The atoms of the naphthopyran three-ring system deviate by an average of 0.037 (19) A from the best least-squares plane through the three rings. Each of the carboxyl group planes is substantially inclined to the naphthopyran ring plane, the average dihedral angle measuring 62 (1) degree. The Na ion is coordinated by O atoms in a highly distorted octahedral geometry with a mean Na--O distance of 2.49 (12) A. A short hydrogen bond is formed between a carboxylic acid group and a carboxylate anion; the H...O(acceptor) distance is 1.35 (5) A and the O...O(acceptor) distance is 2.475 (3) A. The acid H-atom position is located asymmetrically with respect to the O atoms. The water H atoms are involved in unequal three-centered hydrogen bonds. The molecules are stacked such that the naphthopyran ring portion of the structure is nearly parallel to the ab cell face and the stacks are connected by the hydrogen bonds.(ABSTRACT TRUNCATED AT 250 WORDS)

STRUCTURE OF TETRALITHIUM 1,4,5,8-NAPHTHALENETETRACARBOXYLATE DODECAHYDRATE

4Li+.C14H4O8(4-).12H2O, M(r) = 544.18, triclinic, P1, a = 9.608 (2), b = 10.034 (2), c = 7.033 (1) A, alpha = 94.29 (1), beta = 96.95 (1), gamma = 64.52 (1) degree, V = 607.4 (2) A3, Z = 1, D chi = 1.49 g cm-3, lambda (Mo K alpha) = 0.71073 A, mu = 1.29 cm-1, T = 295 K, F(000) = 284, R = 0.039 for 2781 unique reflections having I greater than sigma I. The two inequivalent carboxyl groups adopt a non-planar arrangement with respect to the naphthalene core, making dihedral angles of 52.7 (1) and 54.6 (1) degree with it. The Li+ ions are tetrahedrally coordinated by carboxyl and water O atoms. The Li-O distances are in the range 1.906 (3)-2.041 (3) A, averaging 1.97 (4) A; O-Li-O angles are 101.5 (1)-123.9 (1) degree, averaging 109 (6) degrees. Each of the 12 inequivalent water H atoms is involved in hydrogen bonding. Of these bonds, 11 are typical two-centered hydrogen bonds with an average H...O (acceptor) distance of 1.92 (11) A and an average O-H...O (acceptor) angle of 172 (5) degrees. One water H atom is involved in a three-centered hydrogen bond with an average H...O (acceptor) distance of 2.61 (4) A and an average O-H...O (acceptor) angle of 120 (3) degrees. Adjacent organic anions are separated by the Li+ ions and their coordination polyhedra, with the water molecules occupying positions above and below the naphthalene rings and participating in a three-dimensional hydrogen-bonded network.

1,2-Naphthalenedicarboxylic acid: structures of channel clathrates and an unsolvated crystalline phase

(1) 1,2-Naphthalenedicarboxylic acid-diethyl ether, C12H8O4.nC4H10O, M(r) = 216.19, tetragonal, I4(1)/a, a = 22.086 (3), c = 9.463 (3) A, V = 4616 (2) A3, Z = 16, F(000) = 1792 (without ether), F(000) = 1873 (with 2.7 molecules of ether per unit cell), Dx = 1.24 g cm-3 (without ether), Dx = 1.31 g cm-3 (with 2.7 molecules of ether per unit cell), lambda(Mo K alpha) = 0.71073 A, T = 296 K, mu = 0.88 cm-1, R = 0.052 for 1130 unique reflections having I greater than 3 sigma I. (2) 1,2-Naphthalenedicarboxylic acid, C12H8O4, M(r) = 216.19, triclinic, P1, a = 9.027 (1), b = 9.234 (1), c = 7.256 (1) A, alpha = 106.08 (1), beta = 90.79 (1), gamma = 111.80 (1) degrees, V = 535.0 (1) A3, Z = 2, F(000) = 224, Dx = 1.34 g cm-3, lambda (Mo K alpha) = 0.71073 A, T = 296 K, mu = 0.95 cm-1, R = 0.043 for 1216 unique reflections having I greater than 3 sigma I. (3) 1,2-Naphthalenedicarboxylic acid-dimethoxyethane, C12H8O4.nC4H10O2, M(r) = 216.19, tetragonal, I4(1)/a, a = 22.067 (2), c = 9.465 (2) A, V = 4609 (1) A3, Z = 16, Dx = 1.25 g cm-3 (without dimethoxyethane), Dx = 1.39 g cm-3 (with 4.4 molecules of dimethoxyethane per unit cell), lambda(Mo K alpha) = 0.71073 A, T = 296 K.(ABSTRACT TRUNCATED AT 250 WORDS)

Structure of phenoxathiin (phenothioxin), C12H8OS, at 223 K

Mr = 200.25, orthorhombic, P2(1)2(1)2(1), a = 7.758(2), b = 20.506(3), c = 5.896(2) A, V = 938.0(4) A3, Z = 4, Dx = 1.42 g cm-3, lambda(Mo K alpha) = 0.71069 A, mu = 2.88 cm-1, F(000) = 416, T = 223 K, R = 0.044 for 1414 unique reflections having I greater than 3 sigma I. The phenoxathiin molecule is constituted of two very nearly regular planar hexagonal carbocyclic (benzenoid) rings joined to a non-planar heterocyclic ring. The heterocyclic ring geometry is described in terms of two intersecting planes between which the dihedral angle, the molecular fold angle, is 142.3 degrees. The angle at S (C-S-C) is 97.7(1) degrees, while the angle at O (C-O-C) is 117.4(2) degrees. The overall mean C-C distance in the carbocyclic rings is 1.387(7) A. The absence in this structure of the type of disorder previously found in the dibenzofuran structure is readily understandable since eight sets of close approaches involving each molecule were found in the present structure. These close approaches involve S and O atoms as well as H atoms.

Anthracene-1-carboxylic acid.

The title compound, C15H10O2, was found to crystallize in the centrosymmetric space group P2(1)/n. The hydrogen bonding is of the cyclic dimer type about a center of symmetry. The carboxyl O atoms are ordered as is the carboxyl H atom. The anthracene core, while less nearly planar, shows good agreement with the anthracene cores of anthracene-9-carboxylic acid and anthracene-1,6-dicarboxylic acid. The carboxyl group plane makes a dihedral angle of 12.4 (2) degrees with the best-fit anthracene core plane.

Structures of tetrapotassium, tetrarubidium and tetracaesium 1,4,5,8-naphthalenetetracarboxylate hexahydrates

The three title salts are isomorphic except for one structural feature. Each of the two water molecules of the tetrapotassium structure has one H atom disordered over two sites in a cyclic hydrogen-bond arrangement. Disordered H atoms appear not to be present in the tetrarubidium and tetracaesium structures. The effect of cation size on the geometry of the organic anion in these solids is most readily observed in the configuration and conformation of the carboxylate groups. The four unique C-O bond lengths, and the four unique C-C-O bond angles, of the carboxylate groups exhibit more than one value and in a consistent manner among the three structures

Structure of 2,3-naphthalenedicarboxylic acid

C12H8O4, M(r) = 216.20, monoclinic, C2/c, a = 5.087 (2), b = 19.222 (3), c = 9.552 (2) A, beta = 93.81 (3) degrees, V = 932.0 (5) A3, Z = 4, Dx = 1.54 g cm-3, lambda = 0.71073 A, mu = 1.09 cm-1, F(000) = 488, T = 295 K, R = 0.037 for 687 unique reflections having I > 3 sigma (I). In the structure reported here, a twofold axis lies in the plane of the molecule and bisects the three central ring bonds. The average C--C bond distance in the naphthalene core is 1.401 (27) A and the average interior angle 120.0 (14) degrees. The average deviation of the C atoms comprising the naphthalene rings from the best least-squares plane describing the rings is 0.021 (8) A. The plane of the single unique carboxylic acid group makes a dihedral angle of 33.1 (1) degrees with the least-squares plane of the naphthalene core. The carboxylic acid group, in which the observed O--H distance is 1.00 (3) A, forms a cyclic-dimer hydrogen bond across a center of inversion with the H...O(acceptor) distance 1.68 (3) A, the O...O-(acceptor) distance 2.676 (2) A and the O--H...O-(acceptor) angle 174 (3) degrees. The C--O bond lengths indicate no disorder in the carboxylic acid dimers. The molecules are arranged in stacks with the naphthalene cores parallel to the (102) plane and with the hydrogen bonds of the acid groups linking adjacent stacks. This structure of 2,3-naphthalenedicarboxylic acid is essentially the same as that of o-phthalic acid, but with the b cell edge correspondingly larger to accommodate the additional aromatic ring.