Matrix Isolation Infrared Studies of Magnesium Chloride and Magnesium Bromide

The infrared spectra of monomeric and dimeric magnesium chloride and monomeric magnesium bromide trapped in solid argon at 4 to 10°K have been obtained. For the monomer l 2 , two band systems were observed at 603 and 585 cm −1 . The two bands appear to result from different matrix sites. For the MgBr 2 monomer an intense band system was observed in the region 490 to 530 cm −1 with three strong bands at 502, 509, and 520 cm −1 and shoulders at 495 and 526 cm −1 . The origin of these observed multiplets is uncertain but may also result from different matrix sites. For the dimer Mg 2 Cl 4 , bands were observed at 504, 410, and 515 cm −1 . These frequencies are shown to be consistent with an assumed chlorine bridged structure.