Es wurden das Darnpfdruckverhalten und die Infrarotabsorption der stellungsisomeren nOctanole und der entsprechenden hydroxydeuterierten n-Octanole untersucht. Die Temperaturabhiingigkeit des Isotopie-Effektes der Sattigungsdampfdriicke lafit sich durch die Gleichung b -a + --
The total hydroxy-group and the separate high-frequency (h.f.) and low-frequency (1.f.) hydroxy-group concentrations in H faujasites, observed by i.r. spectroscopy and corroborated by other methods, show a dependence of the maximum occupation of h.f. OH groups on the Si/AI ratio of between 15 and 32 OH groups per unit cell for zeolites HY and HX, respectively. In the case of HX zeolites above 70% exchange, decomposition is unavoiable. As a result of band separation the separate amounts of seven kinds of h.f. OH subspecies have been obtained from measurements of their i.r. absorbance and the integrated extinction coefficients of the h.f. OH stretching band for HX and HY zeolites. These subgroups show the same i.r. sub-bands in both HX and HY zeolites, but of different intensities. This may be explained on the basis of different Si/AI ordering schemes by 0 , H groups bonded to silicon atoms, surrounded by I.R. STUDY OF H-FAUJASITES group12 and more than one h.f. OH group, as has been shown by i.r. spectroscopic splitting of the h.f. OH stretching vibration into l 4 o r more sub-bands.', In deep-bed activated DY zeolites (apparently in the ultrastable form, as indicated by large bands at 2760, 2725 and 2670 cm-l) a splitting of the OD stretching vibration into two sub-bands was also 0bser~ed.l~Although the concentrations of individual portions of h.f. and 1.f. OH groups were determined by other authors for some H forms of f a u j a ~i t e s , ~~~ 2o the individual concentrations of OH subspecies (calculated from the split h.f. OH stretching bands) are still unknown. Furthermore, the individual h.f. and 1.f. OH concentrations of the H faujasites were determined by different methods of pyridine adsorptionlg? 2o or using different assumptions concerning overlapped h.f. and 1.f. OH stretching bands, and there are still unanswered questions concerning the dependence of the h.f. OH concentrations on the Si/AI ratios in H faujasites. In order to estimate the location and quantitative distribution of the h.f. OH subgroups we have investigated various HXand HY-type zeolites by means of i.r. spectroscopy.
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