FORSYTH, J., BREEN, C., HUGHES, T. and YARWOOD, J. (2004). The production of nicotineamide during the thermal desorption of 3-cyanopyridine (3CYP) from Ni2+- and Al3+-exchanged bentonite. A TG-NIS, variable temperature DRIFTS and XRD study. Physical Chemistry Chemical Physics, 6 (12), 3184-3191.Full text not available from this repository.
Samples of air-dried and heated Ni2+- and Al(3+ -)exchanged bentonite (SWy-2) have been exposed to 3-cyanopyridine (3CYP) vapour for six days. The resulting intercalates were studied using variable temperature XRD, DRIFTS, thermogravimetry (TG) and TG-MS. The amount of water co-adsorbed with 3CYP did not influence the initial 13.2 Angstrom spacing of the Al3+ -complex but the d-spacing of the heated Ni2+-sample was ca. 5 Angstrom less that the 21.5 Angstrom spacing of its air-dried counterpart. This difference in layer spacings suggests that 3CYP adopts an arrangement in which the plane of the aromatic ring is parallel with the alummosilicate layer in the Al3+-clay whereas in the Ni2+-form the plane of the ring is perpendicular to the clay surface. TG-MS confirmed that 3CYP and water were the major species desorbed from all samples and that the contraction in the d-spacing upon heating the Ni2+-3CYP complex arose from loss of these species. The appearance of a band near 1680 cm(-1) in the VT-DRIFTS spectra at temperatures above 150 degreesC indicated the formation of amide(s). Correlation with TG-MS data confirmed the transformation of small quantities of 3CYP to nicotinamide. Some 3CYP was protonated in the Al3+-samples.
|Research Institute, Centre or Group:||Materials and Engineering Research Institute > Polymers Nanocomposites and Modelling Research Centre > Polymers, Composites and Spectroscopy Group|
|Depositing User:||Jill Hazard|
|Date Deposited:||13 May 2010 09:14|
|Last Modified:||28 Sep 2010 16:12|
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