Investigations on the Thermal Decomposition of Coordination Polymers Based on Copper(I) Halides and 2-Methylpyrazine

Abstract

The thermal behaviour of the three coordination polymers 2 ∞poly[CuX(μ-2-methylpyrazine- N,N′)] (X = Cl (I), Br (II)), and 2 ∞poly[{Cu2l2 (μ-pyrazine-N,N′)2 } · 2-methylpyrazine] (III) was investigated using differential thermal analysis and thermogravimetry (DTA-TG) measurements as well as temperature resolved X-ray powder diffraction in argon and in air. On heating all compounds decompose in two steps. In the first step compound I and II loose one and compound III looses two of the 2-methylpyrazine ligands to form the corresponding 2:1 compounds Cu2Cl2(2 -methylpyrazine) (IV) and 2 ∞poly[Cu2X2 (μ-2 -methylpyrazine-N,N′)] (X = Br (V), I (VI)). From the experiments there is no evidence for the formation of a 1:1 compound of Cul and 2-methylpyrazine as an intermediate phase during the thermal decomposition. On further heating the 2:1 compounds IV, V and VI transform directly to the corresponding copper(I) halides.