Abstract

<h2>Acta Crystallographica Section B</h2><h3>Structural Crystallography and Crystal Chemistry</h3><h3>0567-7408</h3> <h2>research papers</h2> Volume 32 Part 8 Pages 2325-2328 August 1976 <h2>Structural studies of pyridine oximes. II. The crystal and molecular structure of anti -4-pyridinecarboxaldehyde oxime</h2> M. Martínez-Ripoll and H. P. Lorenz Acta Cryst. (1976). B32, 2325 Structural Studies of Pyridine Oximes. II. The Crystal and Molecular Structure of anti-4-Pyridineearboxaldehyde Oxime By M. MARTINEZ-RIPOLL* Instituto de Quimica-Fisica 'Rocasolano' CSIC, Serrano 119, Madrid 6, Spain AND H. P. LORENZ Chemisches Laboratorium der Universitiit Freiburg, Albertstrasse 21, 78 Freiburg (Breisgau), Germany (BRD) (Received 19 January 1976; accepted 16 March 1976) anti-4-Pyridinecarboxaldehyde oxime crystallizes in the monoclinic system, space group P21/n, with four molecules in a cell of dimensions a=9"080 (1), b=5.4366 (4), c= 12"108 (1) A and fl=90.00 (1)°. The calculated density is 1.357 g cm-3. The structure was solved by direct methods and refined by least-squares analysis to an R index of 0.052. The oxime group is twisted 7"7° from the plane through the pyridine ring. The molecules are connected by single hydrogen bonds to form infinite chains similar to those found in the syn configuration of this compound. Introduction Some derivatives of 4-pyridinecarboxaldehyde oxime and 4-pyrimidinecarboxaldehyde oxime (hereafter ab- breviated to