Intercatenated Coordination Polymers (ICPs) of Carboxylato Bridged Zn(II)-Isoniazid and Their Electrical Conductivity

Abstract

Three new coordination polymers (CPs) of coordinated isoniazid (INH) to Zn(II) with succinic acid (H2succ), fumaric acid (H2fum), and terephthalic acid (H2bdc) as organic linker, [Zn(INH)(succ)]n (1), [Zn(INH)(fum)]n (2), and [Zn(INH)(bdc)]n (3), respectively, have been characterized. The structure determination by the single crystal X-ray diffraction technique shows a ZnN2O4 distorted octahedral geometry, and the 1D chain is constituted via the INH and carboxylate coordination along with the hydrogen bonding (N–H···O) which comprises a 2D structure. The CPs, 1 and 2, are isostructural and fabricate supramolecular networks by inclined intercatenation of two 2D layers, while 3 shows parallel intercatenation. The electrical conductivity and Schottky barrier diode behavior have been established by the charge transport mechanism of the compounds at the quasi-Fermi level state. The analysis indicates that the compound 1 has the highest mobility (2.53 × 10 –10 m2 V–1 s–1) than 2 (1.86 × 10–10 m2 V–1 s–1) and 3 (1.89 × 10–10 m2 V–1 s–1) and the highest electrical conductivity (2.26 × 10–4 S m–1) than the others (1.12 × 10–4 S m–1 (2) and 1.25 × 10–4 S m–1 (3)). DFT computation of the structural motif of CPs has calculated the band gap (ΔE: 3.93 eV (1), 4.45 eV (2), 4.26 eV (3)), which supports the progression of conductivity.