Photochemical reactions involving matrix-isolated atoms

Matrix isolation studies of reactive intermediate complexes

“…The matrix isolation technique [36][37][38][39] was developed in the 1950's as one approach to the study of reactive and unusual chemical intermediates. In a matrix experiment, the species of interest is diluted in a large excess of inert gas, and the gas phase mixture is frozen on a cryogenic surface, typically held between 12 and 14 K. These extremely low temperatures serve to stabilize molecular complexes which might either dissociate or further react at room temperature.…”

Matrix Isolation and Characterization of a Reactive Intermediate in Olefin Oxidation with Chromyl Chloride

“…A new band at 1669 cm À1 helps to clarify the composition of the resulting organic product. This must belong to a carbonyl compound whose n(CO) band is shifted to lower wavenumber due to complexation with a Lewis acidic center (the formation of complexes, often only weakly bound, after photoreaction in noble gas matrices is commonly observed [9] ). In addition, since investigations into the concentration dependence showed that only one equivalent of ethylene is involved in the reaction, the organic product must consist of a carbonyl compound with a C 2 unit (OCH 2 can be excluded as the product [10] ).…”

“…The occurrence of carbonyl compounds among the products was explained by rearrangements of certain products during work-up, [3,5] whereas more recent work highlights the relevance of intermediate chromium complexes of these carbonyl compounds. For example, ethylene reacts with the CrO 2 ion in the (8), F4´´´H11 240 (9). Symmetry operations: x À 1, y, z (a), À x 1, À y, À z 1 (b), x, À y À 0.5, z 0.5 (c).…”

Development of an experimental set-up for low-temperature spectroscopic studies of matrix-isolated molecules and molecular ices using synchrotron radiation

“…Over the past few decades, low-temperature techniques have been used by several groups to carry out photophysics and photochemistry of matrix-isolated molecules and molecular ices (Barnes, 1984;Baskir et al, 2009;Bondybey et al, 1996;Chen et al, 2014;Cruz-Diaz et al, 2014a;Dunkin, 1998;Gerber, 2004;Jacox, 2002;Jheeta et al, 2013;Klaeboe & Nielsen, 1992;Ochsner et al, 1998;Perutz, 1985;Pfeilsticker et al, 2001;Tasumi & Nakata, 1985;Viswanathan et al, 2006;Wu et al, 2009Wu et al, , 2012Young, 2014). Matrix-isolation spectroscopy (MIS) is a well established technique in which the sample of interest (guest) is mixed with a large excess of inert gas (host) and deposited on a substrate at low temperature ($ 10 K) (Moss et al, 2004;Barnes, 1984;Baskir et al, 2009;Bondybey et al, 1996;Dunkin, 1998;Gerber, 2004;Jacox, 2002;Klaeboe & Nielsen, 1992;Lu et al, 2006;Norman & Porter, 1954;ISSN 1600-5775 # 2018 International Union of Crystallography Perutz, 1985;Pfeilsticker et al, 2001;Sneep et al, 2006;Tasumi & Nakata, 1985;Tiedje et al, 2001;Viswanathan et al, 2006;Whittle et al, 1954;Wu et al, 2009). Highly reactive molecules or radicals with very short lifetimes are thus stabilized in inert matrices and spectroscopic studies of such...…”