Synthesis, Crystal Structure and Thermal Reactivity of New Copper( I ) Halide Pyrimidine‐Containing Coordination Polymers

Reaction of copper( I ) chloride with pyrimidine in acetonitrile leads to the formation of the ligand‐rich 1:1 compound poly[CuCl(μ 2 ‐pyrimidine‐ N , N ′)] ( 1 ). “Zig‐zag”‐like CuCl chains are found in the crystal structure that are connected by the pyrimidine ligands to form layers. This compound loses half of its ligands upon heating and transforms into the new l2:1 coordination polymer poly[(CuCl) 2 (μ 2 ‐pyrimidine‐ N , N ′)] ( 2 ). In this structure, ladder‐like CuCl double chains occur which are connected by the pyrimidine ligands to form layers. If copper( I ) iodide is used in the synthesis, the new 1:1 coordination polymer poly[CuI(μ 2 ‐pyrimidine‐ N , N ′)] ( 3 ) forms. In contrast to compound 1 , CuI single chains and (CuI) 2 dimers are found as the CuX substructure, and these are connected by the ligands to form sheets. On heating this compound a similar behaviour as for compound 1 is observed, and a transformation into the new 2:1 compound poly[(CuI) 2 (μ 2 ‐pyrimidine‐ N , N ′)] ( 4 ) occurs. This compound is not isotypic to 2 even though the topology of the coordination network is identical (CuI double chains are connected into layers by the pyrimidine ligands). The thermal behaviour of the known compounds poly[CuBr(μ 2 ‐pyrimidine‐ N , N ′)] ( 5 ) and poly[(CuBr) 2 (μ 2 ‐pyrimidine‐ N , N ′)] ( 6 ) was also investigated. A transformation of the ligand‐rich 1:1 compound 5 into the 2:1 compound 6 is also observed in the thermal decomposition reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)