Mercury(II) iodide coordination polymers generated from polyimine ligands

A series of new HgI2 organic polymeric complexes, [Hg2(L1)I4]n (1), [Hg(L2)I2]n (2), [Hg(L3)I2]n (3), [Hg2(L4)I4]n (4), [Hg(L5)I2]n (5), [Hg(L6)I3](HL6) (6) {L1 = 1,4-bis(2-pyridyl)-2,3-diaza-1,3-butadiene, L2 = 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene, L3 = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene, L4 = 2,5-bis(2-pyridyl)-3,4-diaza-2,4-hexadiene, L5 = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene and L6 = 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene} was prepared from reactions of mercury(II) iodide with six organic nitrogen donor-based ligands under thermal gradient conditions using the branched tube method. All these compounds were structurally characterized by single-crystal X-ray diffraction. The HgI2 coordination polymers obtained with the ligands L2, L3 and L5 show one-dimensional zig-zag motifs and in these compounds the HgI2 units are connected to each other by the ligands L2, L3 and L5 through the pyridyl nitrogen atoms. The L1 and L4 ligands in the compounds 1 and 4 act as both a chelating and bridging group. In the compound 6 the ligand L6 acts as a monodentate ligand, resulting form a discrete compound. The thermal stabilities of compounds 1–6 were studied by thermal gravimetric (TG) and differential thermal analyses (DTA).

Graphical abstractA series of new HgI2 organic polymeric complexes, [Hg2(L1)I4]n (1), [Hg(L2)I2]n (2), [Hg(L3)I2]n (3), [Hg2(L4)I4]n (4), [Hg(L5)I2]n (5), [Hg(L6)I3](HL6) (6) {L1 = 1,4-bis(2-pyridyl)-2,3-diaza-1,3-butadiene, L2 = 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene, L3 = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene, L4 = 2,5-bis(2-pyridyl)-3,4-diaza-2,4-hexadiene, L5 = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene and L6 = 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene} was prepared from reactions of mercury(II) iodide with six organic nitrogen donor-based ligands under thermal gradient conditions using the branched tube method.Figure optionsDownload full-size imageDownload as PowerPoint slide