Iron(II) spin transition 1,2,4-triazole chain compounds with novel inorganic fluorinated counteranions

New one-dimensional spin transition coordination polymers of formula [Fe(NH(2)trZ)(3)](AF(6)) center dot nH(2)O (A = Ti, Zr, Sn; NH(2)trz = 4-amino-1,2,4-triazole) have been synthesized in MeOH and EtOH media. These materials display an abrupt and hysteretic spin transition around 200 K as well as a reversible thermochromic effect on, cooling. A preliminary evaluation of the lattice dynamics in the high-spin and low-spin states is presented. (c) 2006 Elsevier Ltd. All rights reserved.