Cyanide-bridged bimetallic multidimensional structures derived from organotin(IV) and dicyanoaurate building blocks: ION exchange, luminescence, and gas sorption properties

Abstract

The recent success of using methyltin(IV) cations in constructing multidimensional structures containing the Au-CN-Sn link with interesting physical properties will be surveyed. The methyltin(IV)-dicyanoaurates, Me 3Sn[Au (CN) 2] (1) and Me 2Sn[Au(CN) 2] 2 (2) containing the Au- CN-Sn link can be easily prepared by aqueous reaction of Me 3SnCl or Me 2SnCl 2 with stoichiometric amounts of an aqueous solution of K[Au(CN) 2]. The room temperature solid-state emission spectrum of 1 excited at 254 nm shows two intense emission bands at 442 and 670 nm, and a shoulder at 390 nm. When excited at 320 nm, the crystalline sample shows two intense emission bands at 442 and 720 nm, and a shoulder at 380 nm. After 2 min of grinding, only the blue emission band at 442 nm is observed. In contrast, the emission spectrum of 2 shows only one emission maximum at 422 nm. The porosity of 1 and 2 was probed by gas sorption measurements performed at 77 K. 1 exhibited no detectable microporosity as revealed by the inspection of the N 2, H 2, as well as, O 2 isotherms. The gas adsorption studies reveal that only a small amount of N 2 and H 2 (3.82 and 4.66 cm 3 g ?1, respectively) is adsorbed by the framework of 2 at 77 K. However, a CO uptake of 11.20 cm 3 g ?1 can be reached at 1 atm. The framework of 2 can take up significant amounts of O 2 (23.27 cm 3 g ?1). In addition to intriguing photoluminescence and gas sorption behavior, these complexes also exhibit ion exchange properties in the presence of bivalent transition metal cations, such as cobalt(II), nickel(II), copper(II), and zinc(II) © 2012 The Author(s).