Structure and intramolecular hydrogen bonding of 1-phenazinecarboxylic acid.

C13H8N2O2, Mr = 224.22, monoclinic, P2(1)/n, a = 18.149 (2), b = 14.2768 (9), c = 3.8191 (3) A, beta = 92.029 (6) degrees, V = 988.95 A3, Z = 4, Dx = 1.51 g cm-3, lambda (Cu K alpha) = 1.54178 A, mu = 7.61 cm-1, F(000) = 464, T = 163 (1) K, R = 0.037 for 1479 data with I greater than or equal to 2 sigma (I). An intramolecular hydrogen bond is observed between the carboxyl hydrogen atom and the nearby nitrogen atom with the N...O distance being 2.67 A.