science-softCon uv/vis+ photochemistry database; www.photochemistry.org; (C) science-softCon 2019 Substance: dibromomethane Other Names: methylene bromide Formula: CH2Br2 CAS-No.: 74-95-3 PubChem: CID 3024 Study: uv absorption cross sections Authors: J.C. Mössinger, D.E. Shallcross, R.A. Cox Title: UV-VIS absorption cross-sections and atmospheric lifetimes of CH2Br2, CH2I2 and CH2BrI Journal/Source: J. Chem. Soc., Faraday Trans., 94, 10, 1391-1396, (1998); DOI: 10.1039/A709160E Data: table, diagram Energy/Wavelength range: 215 - 300 nm Resolution: Temperature: 298 K Temperature dependence: yes Pressure/Concentration: Phase: gas pH: Comments: The UV/VIS absorption spectra of CH2Br2, CH2I2 and CH2BrI have been measured over the wavelength range 215-390 nm using a dual-beam diode array spectrometer. The spectra consist of broad continuous absorption bands. CH2Br2 exhibits its maximum cross-section of sigma = 2.71 (±0.16) ×10-18 cm2 molecule-1 at lambda = 219 nm. The temperature dependence of the cross-sections was investigated over the range 348-250 K. A decline in the cross-sections with decreasing temperature was observed in the tail of the spectra. Author to whom correspondence should be addressed: (e-mail address):