Exploration of silver borates with diverse low-dimensional anion frameworks by introducing monovalent heteroanions

Borate crystals have gathered widespread focus due to their rich chemical structures and unique properties. Four centric Ag–borates, Ag7B9O16(OH)2(1), Ag8B8O15Cl2(2), Ag8B8O15(OH)Br (3), and Ag11B8O16I3(4), with diverse B–O anion groups and frameworks have been successfully obtained by the mild hydrothermal methods. (1) and (4) have one-dimensional structures and contain {[B11O24(OH)2]17−}∞ and {[B9O20]13−}∞ anion chains, respectively. (2) is 2D borate chloride with unprecedented [B9O21] (9B: 9 : 3[(3 : Δ + 2□)) fundamental building blocks. (3) is the first hydroxy-silver borate bromide and has novel B8O19(OH)] (8B: 3Δ5□ (2(3 : Δ + 2□) + (3□) + 1 : Δ)) fundamental building blocks. (2) and (3) possess the involuted 2D B–O framework with three types of channels, namely, 12-, 16- and 20-membered-ring (MR) channels. (4) represents the first one-dimensional structure in Ag–borate iodides. Complete experimental characterizations, structural features, optical properties, and theoretical calculation analyses of (1) to (4) are presented in this work. This work provided a reference for the syntheses of new borates with diverse boron–oxygen blocks.