New Low-Dimensional Perovskites Based on Lead Bromide

The reactions of lead bromide with 7,7,8,8-tetracyanoquinodimethane and anthracen-9-ylmethanamine hydrobromide in dimethylformamide (DMF) afford the known low-dimensional perovskite {PbBr2(DMF)}n (I) with an impurity of a new hybrid 1D perovskite {Ca(DMF)6[PbBr3]2}n (II), which is isolated in the individual form and characterized by X-ray diffraction analysis. In the crystal of compound II, lead bromide forms infinite chains of PbBr5 octahedra with one vacant vertex between which calcium cations coordinated by the DMF molecules are arranged. The calcium cations presumably have got into the reaction mixture from water used for the washing of the reaction vessel for crystallization after the previous attempt of the synthesis. An attempt of the purposeful preparation of this hybrid 1D perovskite from various calcium salts as sources of this metal ion gives one more new low-dimensional perovskite {Ca(DMF)6[PbBr2.3Cl0.7]2}n (III) in which halide anions (bromide and chloride anions from lead bromide and calcium chloride, respectively) build up the coordination sphere of the lead ion to an octahedral one inducing no noticeable changes in the crystal packing compared to that of compound II. The X-ray diffraction results are deposited with the Cambridge Crystallographic Data Centre (CIF files CCDC nos. 2045586 (I), 2047219 (II), and 2047220 (III)).