Preparation and single-crystal structure of mesitylene sorption complex of fully dehydrated fully Mn 2+-exchanged zeolite Y (FAU)

Abstract

The single-crystal structure of a mesitylene sorption complex of fully dehydrated fully Mn 2+-exchanged zeolite Y, |Mn 37.5(C 9H 12) 15|[Si 117Al 75O 384]-FAU, has been determined by single-crystal synchrotron X-ray diffraction techniques in the space group Fd 3 ¯ m at 100(1) K. A fully dehydrated fully Mn 2+-exchanged zeolite Y crystal (|Mn 37.5|[Si 117Al 75O 384]-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 σ( F o)) of R 1 = 0.063 and wR 2 = 0.151. In this structure, 37.5 Mn 2+ 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 Mn 2+ ions at the first site II (Mn 2+-mesitylene center = ca. 2.65 Å). Of the three hydrogen atoms per methyl group, one is calculated to be 2.14 Å from a framework oxygen and another one is 2.48 Å from another framework oxygen atom. Mesitylene appears to be slightly distorted in the same way.