Matrix isolation studies on Cs2[CO3], Rb2[CO3], and K2[CO3]. The shape of molecular K2[CO3]

Abstract

This paper describes the results of a matrix isolation i.r. spectroscopic study on the vaporisation of the alkali-metal carbonates Cs₂[CO₃], Rb₂[CO₃], and K₂[CO₃]. When these materials are heated in vacuo and the products condensed in nitrogen matrices at low temperatures, the i.r. spectra obtained show the presence of the molecular carbonates together with CO₂ and a number of minor features. With the aid of ¹⁸O enrichment, it is suggested that K₂[CO₃] has a C_2v structure with characteristic i.r. bands at 1 471.6 (B₂), 1 317.4 (A₁), 1 010.1 (A₁), 869.8 (B₁), and 696.7 (B₂) cm^–1.