One-dimensional coordination polymers generated from 1,2-bis(x-pyridyl)butadiyne (x = 3 and 4) and bis(hexafluoroacetylacetonato)M(ii) (M = Cu, Mn, Zn)

Abstract

The coordination chemistry of the long conjugated bidentate ligands 1,2-bis(3-pyridyl)butadiyne (L1) and 1,2-bis(4-pyridyl)butadiyne (L2) with M(hfac)₂ (M = Cu, Mn, Zn; hfac = hexafluoroacetylacetonate) is investigated. Four new coordination polymers are prepared by solution reactions and are fully characterized by infrared spectroscopy, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. [Cu(L1)(hfac)₂]_n (1), [Mn(L1)(hfac)₂]_n (2) and [Zn(L1)(hfac)₂]_n (3) are obtained by combination of L1 with Cu(hfac)₂·H₂O, Mn(hfac)₂·3H₂O and Zn(hfac)₂·2H₂O, respectively, in a methylene chloride/methanol mixed-solvent system. Compounds 1–3 are isostructural and adopt a one-dimensional zigzag chain structural motif, consisting of alternating stacking of L1 and hfac molecules along the crystallographic c-axis. O⋯H–C hydrogen-bonding interactions in 1–3 play a significant role in aligning the polymer in a two-dimensional network. [Mn(L2)(hfac)₂]_n (4) is obtained from the reaction of L2 with Mn(hfac)₂ in an acetone/methylene chloride/methanol mixed-solvent system. The structure features a network of one-dimensional linear chains.