title: Coordination polymers of Fe(iii) and Al(iii) ions with TCA ligand: distinctive fluorescence, CO2 uptake, redox-activity and oxygen evolution reaction.
abstract: Fe and Al belong to different groups in the periodic table, one from the p-block and the other from the d-block. In spite of their different groups, they have the similarity of exhibiting a stable 3+ oxidation state. Here we have prepared Fe(iii) and Al(iii) based coordination polymers in the form of metal-organic gels with the 4,4',4''-tricarboxyltriphenylamine (TCA) ligand, namely Fe-TCA and Al-TCA, and evaluated some important physicochemical properties. Specifically, the electrical conductivity, redox-activity, porosity, and electrocatalytic activity (oxygen evolution reaction) of the Fe-TCA system were noted to be remarkably higher than those of the Al-TCA system. As for the photophysical properties, almost complete quenching of the fluorescence originating from TCA was observed in case of the Fe-TCA system, whereas for the Al-TCA system a significant retention of fluorescence with red-shifted emission was observed. Quantum mechanical calculations based on density functional theory (DFT) were performed to unravel the origin of such discriminative behaviour of these coordination polymer systems.
authors.affiliation: Department of Chemistry, IISER Pune, India. nballav@iiserpune.ac.in.
authors.forename: Barun
authors.initials: B
authors.lastname: Dhara
authors.affiliation: Department of Chemistry, IISER Pune, India. nballav@iiserpune.ac.in.
authors.forename: Subrahmanyam
authors.initials: S
authors.lastname: Sappati
authors.affiliation: Physical and Materials Chemistry Division, CSIR-NCL Pune, India.
authors.forename: Santosh K
authors.initials: SK
authors.lastname: Singh
authors.affiliation: Physical and Materials Chemistry Division, CSIR-NCL Pune, India.
authors.forename: Sreekumar
authors.initials: S
authors.lastname: Kurungot
authors.affiliation: Department of Chemistry, IISER Pune, India. nballav@iiserpune.ac.in and Department of Physics, IISER Pune, India.
authors.forename: Prasenjit
authors.initials: P
authors.lastname: Ghosh
authors.affiliation: Department of Chemistry, IISER Pune, India. nballav@iiserpune.ac.in.
authors.forename: Nirmalya
authors.initials: N
authors.lastname: Ballav