Isonicotinic acid

C 6 H 5 N0 2 , M.W. 123-11, triclinic, space group PI; a = 7-231 (1), 6 = 7-469 (1), c = 6-392 (1) A; a = 114-88 (2), /?= 106-19 (1), y= 103-66 (2)° (from double-radius Weissenberg photographs with A1 calibration lines); D 0 =l-47, Z) c = 1-488 g cm" 3 ; ^=9-75 cm" 1 .The final residual R = 0-056.The molecule takes the neutral form in the crystal.