The FT-infrared and Raman microscopy spectra of the 2′, 6′-dimethoxyflavone and its 1: 1 complex with formic acid in solid state have been recorded and analysed. Some vibrational components appear as specific to the cis-rotamer of formic acid in the crystalline sample, especially the CH group stretching vibration feature. The broad and intense infrared absorption observed in the range 3400–1900 cm− 1 and assigned to the hydrogen ...
