No abstract

Specular reflectance infrared and electron spin resonance spectroscopies were employed for the analysis of the sites of Li(), Cu() and Cd() cations fixed in the structure of montmorillonite from Jels ˇovy ´Potok (Slovakia) upon heating for 24 h at 300 °C. Li() cations are trapped in two different sites: in the previously vacant octahedra and in the hexagonal holes of the tetrahedral sheet. Cu() cations are fixed deep in the hexagonal holes. They substantially affect the vibration modes of Si-O bonds and they can be partially coordinated by oxygen atoms from the mineral layers and by nitrogen atoms from pyridine molecules, if present in the interlayers. The larger Cd() cations do not get so deep into the hexagonal holes as the Cu() ions and their effect on Si-O bonds is less pronounced.The authors acknowledge the financial support of NATO 89, 831. 41 F. A. Cotton and G. Wilkinson, Advanced Inorganic Chemistry,