The reaction Of CoCl2 center dot 6H(2)O, 1,2,4-triazole, and H2O at 200 degrees C for 96 h yields purple rods Of [Co-2(trz)(3)Cl] (1; trz = 1,2,4-triazolate) in 90% yield. The structure of 1 consists of {Co(trz)(3)}(n)(n-) chains of Coll sites linked through tetrahedral sites of {CoN3Cl} geometry into a three-dimensional framework. The competing antiferromagnetic interactions of the octahedral and tetrahedral Co-II centers result in weak ferromagnetic behavior below T-c = 9 K.