A new supramolecular semi conductor cobalt organometallic complex: structural study, optical and electrical properties

• Published in: Journal of molecular structure Vol. 1266; p. 133518
• Main Authors: Ameni, BEN NASR, Abderrazek, OUESLATI, Thierry, ROISNEL, Walid, REKIK
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-10-2022; Elsevier
• Subjects: Chemical Sciences; complex impedance; Crystal structure; optical; relaxation phenomenon; thermal behavior; thermal behavior; complex impedance; relaxation phenomenon; optical; Crystal structure; Relaxationphenomenon; Compleximpedance; Optical; Thermalbehavior; Crystalstructure
• ISSN: 0022-2860; 1872-8014; 0022-2860
• DOI: 10.1016/j.molstruc.2022.133518

•Two different coordination spheres around cobalt cations in a suprmolecular hybrid material.•The DSC curve reveals the presence of one phase transition which is confirmed by electrical measurements.•Optical properties confirm the semi-conducting nature of the title complex with an indirect band gap.•Electric measurements reveal the presence of relaxation phenomenon.
Crystals of a novel Cobalt complex [Co(C3H7NO)6][CoBr1.93Cl2.07] were synthesized by a slow evaporation technique at room temperature. Crystal structure, energy dispersive X-ray spectroscopy (EDX), FT-Infrared (IR), thermal behavior, optical analysis, and impedance spectroscopy measurements were provided to characterize this complex. The crystal structure study showed that the cohesion of this complex is assured through N-H…Br/Cl and N-H...O hydrogen bonds giving birth to a 3-D architecture. Infrared spectroscopy is realized to confirm the structural composition and examine the vibrational properties of this complex. The optical absorption spectrum shows that this new complex has an indirect band gap of Eg = 3.71 eV. Differential scanning calorimetry analysis (DSC) showed an endothermic peak around 354 K on heating, which is assigned to a phase transition since no decomposition of the titled compound is evidenced by thermogravimetric analysis (TGA). The temperature dependence of the conductivity (σdc) and the dielectric properties confirm the presence of this phase transition already observed by thermal analysis. A deep investigation of complex impedance spectra showed that the electrical properties of the material are heavily dependent on frequency and temperature, indicating a relaxation phenomenon and semi-conductor-type behavior.
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