Structural studies of benzene derivatives. II. Refinement of the crystal structure of p-nitrobenzoic acid

Abstract

, has been refined by full-matrix least squares to a final R of 0.040, with 1473 independent non-zero reflexions measured on an automated single-cystal diffractometer. Crystals are monoclinic, space group A2/a, with a = 12.918 (2), b = 5-042 (2), c = 21-298 (6) ,/~, fl--96.66 (2) °, Z = 8. The six-membered C ring has C~, (mm) symmetry, within experimental error; the deviations from D6n (6/mmm) symmetry are interpreted as the substituent effect of the nitro-group. The internal angles at the ipso atoms are: %o2 = 123.3 (1), aCOOH = 120.4 (1) °.

The structure of the new insect-growth regulator 1,4-bis(5-chloropent-4-ynyloxy)benzene

“…The mean aromatic C-C distance of 1.387 (7)/k conforms to the value generally accepted for the C-C length (1.398 A.) in unsubstituted benzene (Colapietro & Domenicano, 1977, and references therein). The O-C(5) bond length of 1.449 (6) /I~ is at the limit for a normal paraffinic C-O bond distance ll.426 (5) /k; Sutton, 1965 l, whereas the shortening of the phenyl-O bond to 1,370 (6) A is in agreement with the value of 1.367/k found in a variety of alkoxybenzenes (Sletten, 1973(Sletten, , 1974(Sletten, , 1975Ruban & Luger, 1975;Rabinovich & Schmidt, 1970;Rousseaux, Meunier-Piret, Putzeys, Germain & Van Meerssche, 1972;Hecht & Luger, 1974;van den Hark, Hendriks & Beurskens, 1974;van Koningsveld, 1973;Cotrait, Sy & Ptak, 1975;Bryan & Jenkins, 1975;Bryan & Fallon, 1975; (Sutton, 1965) and within the range 1.416-1.48 A for simple alkynes (Simonetta & Gavezzotti, 1978).…”

Structural studies of benzene derivatives. X. Refinement of the structure of p-chlorobenzoic acid

“…Ceccarini, 1979) and p-nitrobenzoic acid (Colapietro & Domenicano, 1977). The asymmetries of the ring geometry obtained in the previous study (Miller, Paul & Curtin, 1974) have now disappeared.…”

Structural studies of benzene derivatives. VI. Refinement of the crystal structure of p-hydroxybenzoic acid monohydrate

“…As part of a research project aimed at measuring accurately the effect of various para substituents on the molecular geometry of benzoic acid (Colapietro & Domenicano, 1977Colapietro, Domenicano & Marciante, 1978;Colapietro, Domenicano & Pela Ceccarini, 1979) we report the structure ofp-hydroxybenzoic acid monohydrate. An X-ray diffraction study of this material was published by Fukuyama, Ohkura, * Part v: Colapietro, Domenicano & Pela Ceccarini (1979).…”