Anthracene-9-carboxylic Acid

Abstract

Anthracene-9-carboxylic acid, 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 is almost planar and shows good agreement with the anthracene core of anthracene-1, 8-dicarboxylic acid. The carboxyl group plane makes a dihedral angle of 54.87 (6) degrees with the best-fit anthracene core plane.

Polymorphism in Self-Assembled Structures of 9-Anthracene Carboxylic Acid on Ag(111)

“…AnCA molecular crystal has a P 2 1 / n symmetry with a = 0.39 nm, b = 0.94 nm, and c = 2.9 nm, (see Figure 1 for the structure) [31]. This crystal structure can be rationalized as molecular dimer planes stacked along the [100] direction.…”

Crystal Structure of the 9-Anthracene–Carboxylic Acid Photochemical Dimer and Its Solvates by X-ray Diffraction and Raman Microscopy

“…Ito claimed that the head-to-head isomer was actually more stable as a solid than in solution, thus suggesting that both isomers could be obtained and analyzed in their crystal state. Moré et al studied by optical spectroscopy the kinetics of the crystal reaction, which is assumed to give the head-to-head product, as detected by NMR and in agreement with the monomers pair packing in the crystal lattice of both 9ACA known polymorphs. − Despite the fact that after 77.8 h of irradiation the crystal samples still displayed the X-ray pattern of the monomer, with only an increased disorder, the evidence of the chemical process was clear from the spectroscopic data. Most recently Bardeen and co-workers ,, described the reversible twisting of crystalline microribbons of 9ACA under light irradiation.…”

“…Single crystals of 9ACA suitable for irradiation in the solid state were grown by slow evaporation either from ethyl acetate or p- xylene solutions, following the procedure described in ref . In the former case the monoclinic P 2 1 / n -9ACA polymorph was obtained, , which was also the only present in the pristine material, as verified by randomly sampling numerous crystallites by confocal Raman spectroscopy in the lattice phonon region. In the latter case the triclinic polymorph of 9ACA was obtained instead. , Both polymorphs appear as light yellow needles a few millimeters long.…”

Thermodynamic study of 9-anthracenecarboxylic acid

“…The specific density of 9-anthracenecarboxylic acid, used to calculate the true mass from the apparent mass in air is q = 1.397 g Á cm 3 [13]. The relative atomic masses used for the elements were those recommended by the IUPAC Commission in 2007 [17].…”

“…The crystalline structure of this acid has been solved by Fitzgerald and Gerkin [13], through X-ray studies. The 9-anthracenecarboxylic acid was found to crystallize in a monoclinic crystal system, with a centrosymmetric space group P2 1 /n.…”