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 (H 2 succ), fumaric acid (H 2 fum), and terephthalic acid (H 2 bdc) 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 ZnN 2 O 4 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 m 2 V –1 s –1 ) than 2 (1.86 × 10 –10 m 2 V –1 s –1 ) and 3 (1.89 × 10 –10 m 2 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 (Δ E: 3.93 eV ( 1 ), 4.45 eV ( 2 ), 4.26 eV ( 3 )), which supports the progression of conductivity.