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

Z. Naturforsch. 56 b, 997-1002 (2001); received June 8 , 2001 Copper(I) Halides, 2-Methylpyrazine, Coordination Polymers The thermal behaviour of the three coordination polymers <2..poly[CuX(/u-2-methylpyrazineN,N')] (X = Cl (I), Br (II)), and ^poly[{Cu 2 l 2 (iM-pyrazine-N,N')2 } • 2-methylpyrazine] (III) was investigated using differential thermal analysis and thermogravimetry (DTA-TG) measure­ ments 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 com­ pound III looses two of the 2-methylpyrazine ligands to form the corresponding 2:1 compounds Cu2 Cl2 (2 -methylpyrazine) (IV) and c|,poly[Cu2 X2 (//-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.