Structure of 2,4-diamino-6-(2,4-diphenyl-1-cyano-1,3-butadien-1-yl)-5-cyano-nicotinonitrile

An x-ray diffraction structural analysis was carried out to determine the structure of the 12 solvate of 2,4-diamino-6-(2,4-diphenyl-1-cyano-1,3-butadien-1-yl)-5-cyano-nicotinonitrile with acetonitrile (I) using Mo radiation to R=0.043. The unit cell parameters of the monoclinic crystals of I are as follows: a=11.019, b=23.541, c=9.861 Å, =105.45°, d _calc =1.27, Z=4, space group P2₁/c. The nonplanar, sterically strained molecule has trans configuration with E arrangement of the substituents in the butadiene fragment. The molecular packing in the crystal solvate is determined by the hydrogen bonding between the amino and cyano groups and coulombic interactions due to the polar nature of the acetonitrile molecules. The effect of the substituents on the pyridine ring geometry, analogous to that reported for benzene derivatives, is discussed.Research Institute for Organic Intermediates and Dyes and A. N. Nesmeyanov Institute of Heteroorganic Compounds, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 30, No. 5, pp. 114–122, September–October, 1989.