High-pressure infrared spectra of 1,4-benzoquinone and tetrafluoro-1,4-benzoquinone

The pressure dependence of the infrared spectra (600–1800, 2500–3600 cm −1 ) has been measured for 1,4-benzoquinone(2,5-cyclohexadiene-1,4-dione) and fluoranil (2,3,5,6-tetrafluoro-2,5-cyclohexadiene-1,4-dione). No phase changes occur in either compound over the pressure range from ambient pressure to 50 kbar in benzoquinone and to 40 kbar in fluoranil. The pressure dependence of the C-H stretching frequencies in benzoquinone appear to be normal but the CC and CO stretching modes show a much higher dependence on pressure in fluoranil than in benzoquinone.