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Reaction of single crystals of benzoic and trans-cinnamic acids with 200 Torr pressure of ammonia gas in a sealed glass bulb at 20 °C generates the corresponding ammonium salts; there is no sign of any 1:2 adduct as has been reported previously for related systems. Isotopic substitution using ND 3 has been used to aid identification of the products. Adipic acid likewise reacts with NH3 gas to form a product in which ammonium salts are formed at both carboxylic acid groups. Reaction of 0.5 Torr pressure of NO2 gas with single crystals of 9-methylanthracene and 9-anthracenemethanol in a flow system generates nitrated products where the nitro group appears to be attached at the 10-position, i.e. the position trans to the methyl or methoxy substituent on the central ring. Isotopic substitution using 15NO2 has been used to confirm the identity of the bands arising from the coordinated NO2 group. The products formed when single crystals of hydantoin are reacted with NO2 gas under similar conditions depend on the temperature of the reaction. At 20 °C, a nitrated product is formed, but at 65 °C this gives way to a product containing no nitro groups. The findings show the general applicability of infrared microspectroscopy to a study of gas-solid reactions of organic single crystals.

Numerous gas/solid reactions of nitrogen dioxide with organic substrates are investigated preparatively and mechanistically.Gaseous NO2 reacts with crystalline stable free radicals (nitroxyls 1, verdazyl 6) by electron transfer.The nitrite ions formed are irreversibly oxidized by NO2 via oxygen atom transfer.Solid cation nitrates are formed quantitatively.Thione bonds of thiohydantoins 8 are transformed to carbonyl bonds with formation of sulfur and NO presumably via nitrites as intermediates.Hydantoin 13 oxygenates at its free 5-methylene group via C-H abstraction and nitrite or it undergoes N-1 nitration via N-H abstraction depending on the conditions.Both reactions proceed quantitatively. 1,3-Oxazolidin-2-one (15) gives N-nitration and N-nitrosation with the NO produced.Nonenolized crystalline barbituric acids 17 are quantitatively nitrated (C-N bond formation with radicals) at their methylene groups. 4-Hydroxybenzaldehyde (19) and vanilline (22) give quantitative aromatic nitration (C-N bond formation with arenes) without melting.All possible regioisomers are formed.Solid 9-methylanthracene (26) gives a quantitative yield of its 10-nitro derivative 27.Crystalline anthracene (28) and gaseous NO2 yield 3 primary products 29 (cis; trans) and the new dimeric product 30 as well as the stable secondary products 31 and 32.The gas/solid tetranitration of tetraphenylethylene (33) is severely hindered by the water of reaction.However, a 95percent yield of pure tetrakis(p-nitrophenyl)ethylene is obtained if the drying agent MgSO4*2H2O is admixed and the product 34 extracted.The gas/solid procedures avoid solvents and fuming nitric acid.They give pure products without necessity for recrystallization in most cases and they avoid wastes.Atomic force microscopy (AFM) measurements on prominent faces of single crystals of 1a, 11a, 28, and 33 reveal phase rebuildings with well-directed long-range molecular transport.Nanoliquids were only present on (110) of 28.The characteristic AFM features are correlated with known X-ray crystal structure data and compared with previous results.The shape of the features depends on the molecular packing in the crystal bulk and on the molecular shapes.Molecular interpretations of the AFM features are given.

Theoretical data are presented for the determination of second-order rate constants of reaction of electrode-generated intermediates with reactants in limiting concentrations for three common reaction mechanisms.The method is applicable to second-order reactions with rate constants ranging from about 106 M-1s-1 up to the diffusion-controlled limit.In cases where heterogeneous charge transfer kinetics contribute to the response, calculations must be carried out taking into account the heterogeneous rate constant.The kinetic method is demonstrated using the proton transfer reaction between a radical cation and pyridine, with a rate constant of 2.3*108 M-1s-1.The method is potentially applicable to a wide range of reactions of electrode-generated intermediates.

The highly complex matrix of a diesel particulate extract was analyzed for nitrated polynuclear aromatic hydrocarbons (nitro-PAH) by use of fused-silica capillary column GC/thermionic nitrogen-phosphorus (GC/NPD) analysis of HPLC fractions. These samples were found to contain at least 100 nitro-PAH. Positive isomer identification for 17 nitro-PAH has been made utilizing the GC retention times of authentic standards and low- and high-resolution mass spectra as criteria. An additional 45 nitro-PAH were tentatively identified by using one or more of these techniques. Quantitative GC/MS analysis of 1-nitropyrene, 1,3-dinitropyrene, 1,6-di-nitropyrene, and 1,8-dinitropyrene was facilitated by the use of perdeuterated analogues of these compounds as internal standards. Detection limits by the GC/NPD method range between 0. 2 and 0. 5 ppm for the HPLC fractionated samples.

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