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

Abstract

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...

Influence of Structural Isomerism and Fluorine Atom Substitution on the Self-Association of Naphthoic Acid

“…In the case of 2NA, the stacking is slightly different, putting the carboxyl carbon over the meta-carbon in the lower layer. 37 While these arrangements are not likely to hold directly in solution, the positioning of one layer over the other in a staggered manner is consistent with the observed changes in 1 H chemical shifts arising from π-π stacking. than in the case of 4F1NA.…”

“…The position of the carboxyl group is clearly important, for example, in the solid state different stacking arrangements of 1NA and 2NA have been reported. 37 In both molecules, cyclic dimers are formed between carboxylic acid groups, with a slipped stacking motif in the case of 1NA putting the carboxyl carbon over a carboxyl oxygen of a lower layer. In the case of 2NA, the stacking is slightly different, putting the carboxyl carbon over the meta-carbon in the lower layer.…”

2-Naphthoic Acid at 153K

“…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).…”

“…Firstly, the Ueq values for O1 and 02 at low temperature, as at room temperature, are not as large as those for ring-C atoms C6 and C7, and are as large or only slightly larger than those for ring-C atoms C4, C5 and C8; thus, there is again nothing exceptional about the Ueq values for the O atoms. Secondly, analysis of the principal components of the O-atom anisotropic displacement ellipsoids at low temperature, as at room temperature, shows (see Table 3) that their orientations are not consistent with the static disorder model of Leiserowitz (1976), as previously discussed by Fitzgerald & Gerkin (1993). Thirdly, if only thermal effects determine the values of Ueq and if both temperatures are in the high-temperature limit for thermal displacement, the ratios U~q(296)/Ueq(153) should be equal to the ratio of the absolute temperatures, 1.93 (6) (see, for example, Dunitz, Schomaker & Trueblood, 1988).…”

“…On 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.…”