Preparation and single-crystal structure of mesitylene sorption complex of fully dehydrated fully Mn2+-exchanged zeolite Y (FAU)

The single-crystal structure of a mesitylene sorption complex of fully dehydrated fully Mn2+-exchanged zeolite Y, [Mn-37.5(C9H12)(15)][Si117Al75O384]-FAU, has been determined by single-crystal synchrotron X-ray diffraction techniques in the space group Fd (3) over barm at 100(1) K. A fully dehydrated fully Mn2+-exchanged zeolite Y crystal ([Mn-37.5][Si117Al75O384]-FAU, Si/Al = 1.56) was treated with zeolitically dried mesitylene at 297(1) K for 3 days. The structure of the resulting dark-brown crystal was refined using all intensities to the final error indices (using the 570 reflections for which F-o > 4 sigma(F-o)) of R-1 = 0.063 and wR(2) = 0.151. In this structure, 37.5 Mn2+ ions per unit cell are found at four crystallographic positions: 14.5 are at the centers of the double 6-rings (site I) and three are in the sodalite cavity opposite the double 6-rings (site I'). The remaining 20 are found at two nonequivalent sites II, near 6-rings in the supercage with occupancies of 5 and 15, respectively. Fifteen mesitylene molecules per unit cell lie on threefold axes where these interact facially with the 15 Mn2+ ions at the first site II (Mn2+-mesitylene center = ca. 2.65 angstrom). Of the three hydrogen atoms per methyl group, one is calculated to be 2.14 angstrom from a framework oxygen and another one is 2.48 angstrom from another framework oxygen atom. Mesitylene appears to be slightly distorted in the same way. Crown Copyright (C) 2011 Published by Elsevier Inc. All rights reserved.