Two one-dimensional germanium(IV) coordination polymers based on macrocyclic tetraaza[14]annulene with notable semiconducting property

•Two 1D metallomacrocycle-containing coordination polymers 1 and 2 are presented.•The crystal structures of 1 and 2 are determined.•The conductivities of 1 and 2 at r.t. are 1.52 × 10− 8 and 1.18 × 10− 5 S cm− 1.•Protonic conduction makes 2 exhibit greatly higher electrical conductivity.•1 and 2 show outstanding thermal stability.

Two one-dimensional (1D) germanium(IV) coordination polymers (CPs) containing macrocyclic tetraaza[14]annulene, [Ge(tmtaa)(L)]n [tmtaa = tetraaza[14]annulene, L = 1,4-benezedicarboxylate 1; 2,5-dihydroxyl-1,4-benezedicarboxylate, 2], are synthesized and characterized. The temperature dependence of the electrical conductivity (σ) for 1 or 2 indicates region of rising dσ/dT (the conductivity increases with increasing temperature), suggesting semiconductor-like charge transport in the stacking direction. The room temperature electrical conductivities for 1 and 2 are 1.52 × 10− 8 S cm− 1 and 1.18 × 10− 5 S cm− 1, respectively, which are obviously higher than those of most 1D metallophthalocyanine- and metalloporphyrine-containing CPs. Though the crystal structures of 1 and 2 are similar, 2 exhibits better electrical conductivity which is about three orders higher than that of 1. This may be due to the protonic conduction existing in 2. Furthermore, 1 and 2 show outstanding thermal stability. These results suggest the potential applications of 1 and 2 as semiconductive materials.

Graphical abstractTwo 1D Ge(IV) coordination polymers containing macrocyclic tetraaza[14]annulene, 1 and 2, show notable semiconducting property. Though the structures of 1 and 2 are similar, 2 exhibits better electrical conductivity which is about three orders higher than that of 1. This may be due to the protonic conduction existing in 2.Figure optionsDownload full-size imageDownload as PowerPoint slide