Aromatic hydrogen, FTIR

Aromatic positions, deuterium-hydrogen exchange reaction of tetralin-di2 and diphenylmethane, I62t,l63t Aromatic stretching, FTIR of vitrinite, 103-12 Aromatic-to-aliphatic ratios, carbon-13 NMR, 80-95 Aromaticity, 73... 

Working co-operatively with others, we have found some indication that certain alilphatic linkages between aromatic nucleii are involved in the rapid dissolution of coal. The absolute aliphatic hydrogen content as determined by P. Solomon using FTIR (22) shows a very good linear relationship with conversion of coal in 3 minutes to pyridine soluble materials (Figure 14a). 

The possible accumulation of intermediates during the photocatalytic oxidation of aromatic contaminants has been studied with a variety of techniques, including temperature-progranuned desorption (TPD), oxidation (TPO), and hydrogenation (TPH), Fourier transform infrared analysis (FTIR), and extraction of adsorbed species with a variety of solvents. 

Aliphatic stretching, FTIR of vitrinite, 103-12 Alkyl phenols, Py-MS, 153f Analytical analyses of demineralized coals, density fractions, 71t Aromatic adjacent hydrogen in... 

FTIR measurements and ab initio calculations show that iV-methylpyrrole interacts with hexafluoroisopropanol, trifluoroethanol, 2-chloroethanol, and 1-butanol to form 1 1 stoichiometric hydrogen-bonded complexes in which the OH group acts as H-donor and the aromatic 7t-system as acceptor <2003CPH(290)69>. 

Different charge-compensating cations in zeolite L have been tested for their promotional effect in n-hexane aromatization. Apparently, high basicity of the alkaline and alkaline earth promoter favors n-hexane aromatization. Basicity and selectivity both increase from Li and Cs 331) and from Mg to Ba (22,25). Bezouhanova et al. studied the FTIR bands of linearly adsorbed CO in the range of 2060-2075 cm . One band at 2075 cm", which is also found on unsupported Pt, is attributed to extrazeolite Pt particles, a second band shifts from 2060 cm" for Li to lower wavenumbers with K and Rb 331). Another criterion, used by Larsen and Haller, is the measured rate of competitive hydrogenation of benzene and toluene, which has been found to correlate with the zeolite basicity (25). As described in a previous section, this method had previously been used by Tri el al. to probe for the electron deficiency of Pt particles in acidic zeolites 332). The rate data are analyzed in terms of a Langmuir-Hinshelwood model and the ratio of the adsorption coefficients of toluene and benzene, A, /b, is determined. It was found to decrease from 8.6 for Pt/Si02, and 5.4 for Pt/MgL, to 4.4 for Pt/BaL. As direct electron transfer from the cations to neutral Pt particles is unlikely, an interaction of Pt with the zeolite framework or with... 

In-situ FTIR studies of coke pyrolysis and oxidation are described elsewhere in this volume (ref. 50). Pyrolysis (heating in flowing nitrogen) evolves mostly methane and hydrogen, due to demethylation and graphitization of the alkyl aromatic coke molecules, and acid sites are not restored. Heating in flowing air, on the other hand, oxidizes the coke to COg and HgO, and the chemistry of this process has been monitored by FTIR. 

The position of the v(C=N) bands differs depending on the different substituents at the nitrogen atom of the N-benzylidene ring. Typical modes of the aromatic rings appear around 1595/1575cm as well as 1495/1485/1458cm. The respective ATR-FTIR and Raman spectra of the hydrogenation products show less prominent bands with essentially lower intensities ]11]. 

Visentin, F. (2005) Kinetic study of hydrogenation reactions of aromatic nitro compounds using a new pressure resistant reaction calorimeter combined with a FTIR-ATR device. Dissertation, ETH, Zurich, No. 16053. 

An application of FTIR and C NMR spectroscopy on hydrothermal coalification could determine the decomposition of organic compounds in peat at different treated temperature. Increasing the temperature of the hydrothermal treatment resulted in an increase in relative area intensity of the aromatic carbons bound to the hydrogen (Ar-H), aromatic non-oxygenated carbon (Ar-C) and aromatic oxygenated carbon (Ar-O). These mean and also correspond to the increasing of aromaticity as well as coalification degree. 

Wang, F.C., Feve, M., Lam, T.M., and Pascault, J.P. (1994) FTIR analysis of hydrogen bonding in amorphous linear aromatic polyurethanes. I. Influence of temperature. Journal of Polymer Science Part B Polymer Physics, 32, 1305-1313. 

The frequencies of the C—H bond modes are shifted slightly, which allows one to distinguish between sp and sp configurations [173]. Some diamond films contain hydrogen bound to sp carbon, while in other films the sp carbon is below the detection limit [180], The sp sp sp sp (aromatic) transformation of carbon was studied by FTIR [181]. It was shown that this transformation correlates with the release of hydrogen from the films during bombardment by various ionic species. 

---