Structural relationship of two coordination polymers of Cu(i) with the ligand ethanediyl bis(isonicotinate)Electronic supplementary information (ESI) available: Selected crystal data, views of 2, and colour pictures of Fig. 3c and d. See http://www.rsc.org/suppdata/ce/b3/b309410c/

The flexible ligand ethanediyl bis(isonicotinate), L, is used as linking unit for Cu(I) ions in a coordination polymer. Two different structures of one-dimensional chains can be obtained, mainly depending on the co-crystallising solvent. Weak interactions such as hydrogen bonding and pi–stacking, and the exclusion of solvent molecules are responsible for the slow transformation of one compound into the other in the mother liquor.