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

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1952REGULAR STRUCTURAL PAPERS will be published elsewhere in due course.) The 4,6-dilithio derivative of dibenzofuran, obtained from the reaction of dibenzoflwan with three equivalents of sec-butyllithium, was treated with dimethylformamide to afford dibenzofuran-4,6-dicarboxaldehyde. The Wittig-type reaction of this dialdehyde with diethylbenzylphosphonate and tBuOK in dry dimethylformamide gave 4,6-(2,2-diphenylethenyl)dibenzofuran in good yield. This stilbenoid was converted to the desired diphenanthro- m.p. 583-587 K (dec.)] by irradiation with UV fight in the presence of air and iodine. The diphenanthroflLran was crystallized from solution in dimethoxyethane to provide the experimental sample. The sample was mounted on a quartz pin with epoxy cement and a unit cell was determined at room temperature (295 K). The following non-idealized parameters were obtained from a leastsquares fitting of the setting angles for 25 centered reflections: a = 6.825 (2), b --34.842 (4), c = 7.749 (1) A,, oL = 90.01 (2), = 90.01 (2), 3' = 90.01 (2) °, V = 1842.8 (6) A. 3. The crystal was then cooled to 191 K utilizing a Molecular Structure Corporation low-temperature apparatus. The stated temperature was measured continuously during data collection in the cold gas flow just upstream of the crystal; the estimated uncertainty of the crystal temperature is -t-2 K. Unit-cell parameters for the lowtemperature cell were obtained from a symmetry-constrained least-squares fit of the same reflections used to determine the room-temperature cell. The low-temperature unit-cell parameters are given in the Experimental section.Data were collected utilizing graphite-monochromated radiation. Scan widths were (1.4 + 0.35tan0) ° in w, with a background/scan time ratio of 1:2. No corrections were made for decay or absorption; the data were corrected for Lorentz and polarization effects. Systematic absences (Okl, k+l = odd; hk0, h = odd) were consistent with two space groups: Pnma and Pna21. Since intensity statistics indicated a centrosymmetric space group, Pnma (No. 62) was given initial preference; refinement proceeded well and it was adopted.The direct-met,hods program SHELXS86 was used to generate an E map from which the initial positions of the non-H atoms were identified. Fourier difference methods were then used to locate the H atoms. The C and O atoms were refined anisotropically and the H atoms isotropically using full-matrix least squares (TEXSAN; Molecular Structure Corporation, 1989). The weighting scheme used was w = o. Cryst. CA9, 398-400. Gerkin, R. E., . ActaCryst. C40, 1892-1894. Gerkin, R. E. & Reppart, W. J. (1985. Acta Cryst. C41, 961-963. Gerkin, R. E. & Reppart, W. J. (1986). Acta Cryst. C42, 480-482. Johnson, C. K. (1976). ORTEPII. Ridge National Laboratory, Tennessee, USA. Kay, M. I., Okaya, Y. & Cox, D. E. (1971). Acta Cryst. B27, 26-33. Molecular Structure Corporation (1989 Acta Cryst. (1993). C49, 1952-1958 Redetermination of the Structures of 1-Naphthoic Acid and 2-Naphthoic Acid AbstractThe structures of 1...

Section: Commentmentioning

confidence: 61%

Section: Commentmentioning

confidence: 98%

Section: Commentmentioning

confidence: 99%

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

Fitzgerald¹,

Gerkin²

1993

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“…The dimensions of the naphthalene core of this mean anion agree well with those from the tetralithium and tetrasodium structures, the same pattern of bond lengths occurring in all cases. The bond angles around C(4) and C(6) deviate from 120 ° in a manner typical of 1,8-substituted naphthalenes (Fitzgerald, Gallucci & Gerkin, 1991a), while the angle at C(5) is smaller than is normally found for 1,8-substituted naphthalenes. This is presumably a consequence of the interaction on both sides of the naphthalene ring for the tetrasubstituted naphthalene.…”

Section: Commentmentioning

confidence: 65%

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

Fitzgerald¹,

Gallucci²,

Gerkin³

1993

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(Fitzgerald, Gallucci & Gerkin, 1991b). Of particular interest in this series is the effect of cation size on crystal structure and the attendant hydrogenbonding network, as well as on the conformation of the organic anion. Heretofore, no structural series for simple Group IA salts of an aromatic carboxylic acid has been reported. Structures of aromatic acid salts have been reported, and these are compared to the structures of the tetranaphthalate salts. Moreover, there have been few reports of hydrated aromatic salts in which the H atoms have been located and refined successfully. The present study, therefore, was also planned to add appreciably to the structural data available for hydrated aromatic salts. AbstractThe 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.

“…1.362 (3) CI I---O2 1.250 (2) C2-----C I---C9 120.9 (2) C I----C9--C8 121.9 (2) C I ----C2---C3 120.2(2) C 1----C9---C 10 118.7(2) CI---C2----CI I 120.2 (2) C8-----C9-----<210 119.3 (2) C3---C2--~ I 1 119.6(I) C4----C I 0---C5 122.9(2) C2--C3--C4 120.1 (2) C4--C I 0---C9 119.0(2) C3---C4---C I 0 121.0(2) C5--C I 0---C9 118.1 (2) C6--C5---C 10 121.1 (2) C2--CI I---O1 116.7(I) C5---C6---C7 120.3 (2) C2---C 11 ---02 I 19.7 (2) C6---C7---C8 120.5 (2) OI--CI 1----492 123.6 (2) C7---C8---C9 120.6 (2) (3) 117.7(2) 119.1 (2) 123.1 (3) (II),153 K c 1.288(2) 1.250 (2) 116.7(1) 119.7(2) 123.6(2) 01D a 1.312(3) 1.214(3) 114.1 (2) 124.8(2) 121.1 (2) Notes: (a) 1,8-naphthalenedicarboxylic acid, carboxyl-H atoms completely disordered (Fitzgerald, Gallucci & Gerkin, 1991); (b) Fitzgerald & Gerkin, 1993; this study; (d) l-naphthoic acid, carboxyl-H atom completely ordered (Fitzgerald & Gerkin. 1993).…”

Section: Methodsmentioning

confidence: 99%

2-Naphthoic Acid at 153K

Blackburn

Fitzgerald²,

Gerkin³

1996

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The structure of 2-naphthoic acid, C11H802, has been investigated at 153 K in order to determine the degree of disorder of the carboxylic acid group for comparison with that of the room-temperature structure. Analysis of the anisotropic displacement ellipsoids of the carboxyl-O atoms demonstrated that these parameters are wholly consistent with thermal motion of the O atoms. A model with ordered carboxyl-O atoms, but with the acid-H atom refined at two sites with 0.5 occupancy at each, was found to be statistically significantly better than a model with ordered carboxyl-O atoms and an ordered acid-H atom. Thus, as in the room-temperature study, the best structural description is that the O atoms are ordered and the acid-H atom is disordered. Nonetheless, comparisons of the geometric parameters of the carboxyl groups at 296 and 153 K suggest progress toward a fully ordered structure at the lower temperature. Except for the expected slight overall contraction and the slightly altered geometry of the carboxyl group, the structure is virtually the same as at room temperature. CommentOn the basis of their structural study of 2-naphthoic acid, (II), at 296 K, Fitzgerald & Gerkin (1993) concluded that the carboxylic-O atoms were ordered and that the acid-H atom was disordered over two sites of 0.5 occupancy each. It was of interest to determine whether the H atom would become better ordered at our lowest feasible temperature, ,-~ 150 K.