Acta Crystallographica, Section C: Crystal Structure Communications 1996-06-15

Xanthene-9-carboxylic acid.

A C Blackburn, A J Dobson, R E Gerkin

Index: Acta Crystallogr. C 52 ( Pt 6) , 1486-8, (1996)

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Abstract

In xanthene-9-carboxylic acid, C14H10O3, hydrogen bonding is of the cyclic dimer type but involves two crystallographically inequivalent molecules and does not occur about a center of symmetry. The carboxylic H atoms are ordered. The dihedral angle (fold angle) of the xanthene core is 14.2 (1) degree for molecule A and 11.3 (2) degrees for molecule B. The planes of the carboxyl groups are almost perpendicular to the xanthene cores.