Structure of copper-dimethylglyoxime at low temperature

Abstract

The crystal structure of copper-dimethylglyoxime has been examined at liquid-nitrogen temperatures and refined by two-dimensional Fourier syntheses. The unit cell is monoclinic with a-9-71, b-16.88, c = 7.08 A, }6 =-108 ° 26". The space group is P21/n and the unit cell contains 4 molecules of copper-dimethylglyoxime. The two organic radicals bonded to the copper atom do not lie in the same plane, but form an angle of 180°-21 ° 44'. The copper is bonded with four N atoms (Cu-N-1.94 A) and with an O atom in a nearby molecule (Cu-O-~ 2.43 fi~) forming a dimer. There are two hydrogen bonds between pairs of oxygen atoms; when one of these oxygen atoms is bonded to a copper atom the hydrogen bond is very weak.