Intermolecular CH···O-type Hydrogen Bonds in Formyl-Substituted Diphenylhexatriene, a [2+2] Photoreactive Organic Solid: Crystal Structure and IR, NMR Spectrosopic Evidence

Abstract

(E,E,E)-1,6-Bis(4-formylphenyl)-1,3,5-hexatriene (1) underwent [2+2] photodimerization in the solid state. Single-crystal X-ray diffraction analysis revealed that crystal 1 was constructed mainly by CH...O-type intermolecular hydrogen bonds. Based on the results of structural analysis, IR and NMR spectroscopic measurements, and theoretical calculations, the importance of CH...O intermolecular hydrogen bonds in [2+2] photoreactive crystal structure construction will be discussed.