Effect of Counterions on the Formation and Structures of Ce(III) and Er(III) Chloranilate Frameworks

Abstract

Lanthanide-containing benzoquinoid-type frameworks have been of significant interest due to their potential for application in high-density information storage and processing, photoluminescence, and sensing. With physical and chemical properties linked to the dimensionality of coordination polymers, control of network topology is desirable in generating targeted materials. The use of various cations as templates in the synthesis of Ce(III) and Er(III) frameworks has been investigated in this study. 2D (6,3) sheets of composition [M2(can)3(H2O)6]·solvate (M = Ce or Er, can = chloranilate) are formed with the tetraalkylammonium cations, tetramethylammonium or tetrabutylammonium. When the aromatic cation 1-(diphenylmethyl)-pyridinium (DPMP+) is incorporated in the reaction mixture, anionic diamond-type networks of composition [M(can)2]− (M = Ce or Er) are formed, with the cation occupying adamantane-type cavities. The use of tetraphenylphosphonium also yields a diamond-like network but only in the case of [Ce(can)2]−. When methyltriphenylphosphonium is employed, 3D anionic networks with unusual connectivity are obtained.