Three-Dimensional Yttrium Oxalates Possessing Large Channels

Abstract

Two new open-framework yttrium oxalates have been prepared, for the first time, employing hydrothermal methods in the presence of organic amines. The crystal data for these oxalates are as follows: I, [C6N2K16](0.5)Y(H2O)(C2O4)(2). 2H(2)O, triclinic, space group P(-1) (no. 2), a = 8.229(3), b = 9.739(1), c = 9.754(3) Angstrom, alpha = 60.74(1), beta = 72.36(1), gamma = 84.67(1.)degrees, V = 648.5(1) Angstrom (3), Z = 2, M = 377.1., D-calc = 1.931 g cm(-3), mu = 4.554 mm(-1), Mo K alpha, R-1 = 0.054, wR(2) = 0.13; II, [C5N2H12][Y(C2O4)(2)], monoclinic, space group Cc (no. 9), alpha = 11.552(1), b = 17.168(1), c = 8.719(1) Angstrom, beta = 1.30.64(1)degrees V = 1312.1(1) Angstrom (3), Z = 2, M = 35.1, D-calc = 1.848 g cm(-3), mu = 4.48 mm(-1), Mo K alpha, R-1 = 0.023, wR(2) = 0.057. The Y atom is 9-coordinated in I, forming a D-3h triply capped trigonal prism, and 8-coordinated in II, forming a square antiprism. The three-dimensional framework structures of I and II are built up by in-plane linkages between the Y and the oxalate moieties, forming layers with 12-membered honeycomb-like apertures, pillared by another oxalate in an out-of-plane manner. While I possesses channels along all the crystallographic directions, II has channels only in one direction. Adsorption studies indicate that water and methanol can be reversibly adsorbed in I.