A Cu II Chain Compound Showing a Ferromagnetic Coupling through Triple N 1 , N 2 ‐1,2,4‐Triazole Bridges

[Cu(hyetrz) 3 ](CF 3 SO 3 ) 2 ·H 2 O [hyetrz = 4‐(2′‐hydroxyethyl)‐1,2,4‐triazole] represents the first structurally characterised ferromagnetically coupled Cu II chain compound containing triple N 1 , N 2 ‐1,2,4‐triazole bridges. catena ‐ [μ‐Tris{4‐(2′‐hydroxyethyl)‐1,2,4‐triazole‐ N 1 , N 2 }copper( II )] bis(trifluoromethanesulfonate) hydrate (C 14 H 23 F 6 S 2 O 10 CuN 9 ) crystallises in the triclinic space group P $\bar 1$ , a = 13.54(3), b = 14.37(3), c = 15.61(4) Å, α = 95.9(1), β = 104.9(1), γ = 106.5(1)°, V = 2763(11) Å 3 , Z = 4 (Cu II units). The Cu II ions are linked by triple N 1 , N 2 ‐1,2,4‐triazole bridges yielding an alternating chain with Cu1−Cu2 = 3.8842(4) Å and Cu2−Cu3 = 3.9354(4) Å. Analysis of the magnetic data according to a high‐temperature series expansion gives a J value of +1.45(3) cm −1 . The nature and the magnitude of the ferromagnetic exchange have been discussed on the basis of the structural features. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)