Syntheses, structures and magnetic properties of five iron(II) coordination polymers with flexible bis(imidazole) and bis(triazole) ligands

Five iron(II) coordination polymers, {[Fe(bte)2(NCS)2][Fe(bte)(H2O)2(NCS)2]}n (1), [Fe(bime)(NCS)2]n (2), [Fe(bime)(dca)2]n (3), [Fe(bime)2(N3)2]n (4) and [Fe(btb)2(NCS)2]n (5), were synthesized using the flexible ligands 1,2-bis(1,2,4-triazol-1-yl)ethane (bte), 1,2-bis(imidazol-1-yl)ethane (bime) and 1,4-bis(1,2,4-triazol-1-yl)butane (btb), together with NCS−, dicyanamide (dca) and N3−. The compound 1 contains two kinds of motifs (double chain and single chain) and forms a three-dimensional hydrogen bonded network; 2 and 3 contain one-dimensional triple chains; and 4 and 5 form two-dimensional (4, 4) networks. The coordination anions (NCS−, dca and N3−) and the structural characteristics of the ligands (bte, bime and btb) play an important role in the assembly of the topologies. Magnetic studies reveal that 1–5 remain in the high-spin state over the whole temperature range 2–300 K and no detectable spin-crossover is observed.

Five iron(II) coordination polymers were synthesized using flexible ligands. The compound 1 contains two kinds of motifs (double chain and single chain) and forms a three-dimensional hydrogen bonded network, 2 and 3 contain one-dimensional triple chains, and 4 and 5 form two-dimensional (4, 4) networks. Magnetic studies reveal that 1–5 remain in the high-spin state over the whole temperature range 2–300 K.Figure optionsDownload as PowerPoint slideHighlights
► Five iron(II) coordination polymers with bisimidazole/bistriazole and inorganic N-co-ligands.
► Double chain and single chain in one crystal, one-dimensional triple chain and two-dimensional (4, 4) network.
► Five iron(II) coordination polymers remain in the high-spin state.