Knowledge Bank

The x-ray crystal structure of cyanogens at $-95\circ$ recently been determined by Parkes and Hughes in the Laboratory. The space group is $Posb$ with four molecules per unit cell. The infrared spectrum of this polyerystalline films of the material have been examined at $-190\circ$ . Of particular interest is the splitting observed in the antisymmetric stretching mode $v3$. Calculations indicate that transition moment-transition moment interactions do not satisfactorily account for either the magnitude of the splittings or the intensities of the component bands. Other forms of intermolecular coupling will be discussed.