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This work presents the synthesis, characterization, crystal structure and spectroscopic investigations of isophthalohydrazide based probe. Among various tested metal ions, the probe selectively detects Al3+ and Cu2+ in aqueous ethanol via fluorometric and colorimetric methods, respectively. It displays a fluorescence “turn-on” response with Al3+ and visual colour change from colourless to yellow with Cu2+. Sensing mechanism is explored with UV–Vis, fluorescence spectroscopy and 1H NMR titration, and confirmed with computational results. Suppression of C N isomerization and photo-induced electron transfer (PET) along with chelation enhanced fluorescence emission (CHEF) result in “turn-on” fluorescence with Al3+ while ligand to metal charge transfer (LMCT) accounts for visual colour change with Cu2+. Job’s plot and HRMS confirm 1:2 (L:M) stoichiometry. The probe also exhibits efficient reversibility and reproducibility with EDTA which are successfully mimicked with combinatorial logic gate and truth table. Additionally, solid state applications and bio-imaging investigation on gut tissue of Drosophila 3rd instar larvae are performed.

First-principles calculations predict that atomic iron (Fe) combines with fluorine (F) to produce stable molecular complexes having the form FeF n ( n = 1–6) and the species with n ≥ 3 exhibit superhalogen properties. Electron affinities of the complexes are found to increase successively upto 8.20 eV for FeF 6 . The unusual properties of these complexes are due to the involvement of inner shell 3d -electrons, which allow FeF n complexes to belong to the class of superhalogens and also due to the tendency of Fe to have valency that can exceed the value of 3. Quantum chemical calculations were carried out using an all-electron linear combination of atomic orbitals scheme within the density functional theory (DFT) framework utilizing the popular B3LYP (Becke, three-parameter, Lee–Yang–Parr) exchange correlation functional. Analysis of HOMO-LUMO gaps, molecular orbitals and binding energies of these complexes indicate that the FeF n complexes are stable. Population analysis of molecular orbitals was also carried out to determine the percentage (%) contribution of Fe and F atoms to the frontier orbitals (LUMO and HOMO). The orbital overlap population (OOP) diagrams provide information related to bonding and anti-bonding nature of overlap in the molecular orbitals. The principle of maximum hardness was applied to determine the relative stability of the complexes. Also, the stability and viability of novel salt series Li-(FeF n ) has been tested by analyzing the molecules Li-(FeF 4 ), Li-(FeF 5 ) and Li-(FeF 6 ) in detail.

In the present work, a detailed spectroscopic analysis of 4-(benzyloxy)benzaldehyde thiosemicarbazone (3) has been carried out using 1H NMR, 13C NMR, UV–Visible and FT-IR spectroscopic techniques. The quantum chemical calculations have been carried out using DFT level of theory, B3LYP functional and 6-31G(d,p) basis set. The calculated thermodynamic parameters show that the formation of 3 is an exothermic and spontaneous reaction at 25 °C. The vibrational analysis indicates the formation of dimer in the solid state by intermolecular hydrogen bonding (N H⋯S C) and the binding energy of dimer is calculated to be 11.2 kcal/mol, using DFT calculation. NBO analysis is carried out to investigate the charge transfer in various intra and intermolecular interactions involved in dimer. Topological parameters at bond critical points (BCPs) are calculated to analyze the strength and nature of various intra and intermolecular interactions in dimer by Bader’s ‘Atoms in molecules’ AIM theory in detail. The local reactivity descriptors such as Fukui functions ( f k + , f k - ) , local softnesses ( s k + , s k - ) and electrophilicity indices ( ω k + , ω k - ) analysis are performed to determine the reactive sites within molecule. Non linear optical (NLO) behavior of title compound is investigated by the computed value of first hyperpolarizability (β0).

In this paper we have studied the interaction of Rhodium (Rh) atom with Fluorine (F) using density functional theory. Up to seven F atoms are bound to a single Rh atom which results in increase of electron affinities of the given molecule successively, reaching a peak value of 9.05 eV for RhF 7 . By using HOMO–LUMO gap, molecular orbital analysis, binding energy of these clusters, we examined its stability and reactivity. It is found that energy required for dissociation of F 2 molecules are higher than energy required for dissociation of F atoms. The unusual properties are brought about by involvement of inner shell 4d-electrons, which not only allow RhF n clusters to belong to the class of superhalogens but also show that its valence can exceed the nominal value of 1.

Quantum chemical calculations using gradient corrected density functional theory reveals the unusual properties of a platinum (Pt) atom interacting with fluorine (F) and chlorine (Cl) atoms. Up to six F and Cl atoms are bound to a single Pt atom, which results in increase of electron affinities as successive halogen atoms are attached reaching a peak value of 8.05 eV for PtF 6 and 6.46 eV for PtCl 6 . The large HOMO–LUMO energy gap, both in neutral and anionic forms, reveals further evidence of their stability. The unusual properties bring about the involvement of inner shell 5d-electrons, which not only allow PtF n and PtCl n ( n = 1–6) complexes to belong to the class of superhalogens but also show that its valence can exceed the nominal value of 1.

This work deals with the vibrational spectroscopy of 2-formyl benzonitrile. The fundamental vibrational frequencies and intensity of vibrational bands were evaluated using density functional theory (DFT) using standard HF/6-31G(d) and B3LYP/6-31G(d) methods and basis set combinations. The vibrational spectra were interpreted, with the aid of normal coordinate analysis based on a scaled quantum mechanical force field. The infrared and Raman spectra were also predicted from the calculated intensities. Comparison of simulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibrational modes.