New diorganotin(IV) complexes of Schiff base derived from 4‐amino‐3‐hydrazino‐5‐mercapto‐4H‐1,2,4‐triazole: Synthesis, structural characterization, density functional theory studies, atoms‐in‐molecules analysis and antifungal activity

Abstract

New diorganotin(IV) complexes of a Schiff base (HL) having general formula R2Sn(L)Cl (where L is the monoanion of HL and R = n‐Bu or Ph) have been synthesized and characterized using elemental analysis, infrared, NMR (1H, 13C, 119Sn) and UV–visible spectroscopies and mass spectrometry. These investigations suggest that in these 1:1 monomeric derivatives the Schiff base ligand acts in a monoanionic bidentate manner coordinating through the Ophenolic and Nazomethine, with proposed distorted trigonal bipyramidal geometry around tin with Ophenolic and two organic groups in the equatorial plane and the Nazomethine and the third organic group in axial positions. The proposed structures have been validated by density functional theory (DFT)‐based quantum chemical calculations at the B3LYP/6‐31G(d,p)/Def2‐SVP (Sn) level of theory. The simulated UV–visible spectrum was obtained with the time‐dependent DFT method in the gas phase and in the solvent field with the integral equation formalism–polarizable continuum model. A comparative analysis of the experimental vibrational frequencies and simulated harmonic frequencies indicates a good correlation between them. An insight into the intramolecular bonding and interactions among bonds in organotin(IV) complexes of HL was obtained by means of natural bond orbital analysis. The topological and energetic properties of the electron density distribution for the tin–ligand interaction in R2Sn(L)Cl have been theoretically calculated at the bonds around the central tin atom in terms of atoms‐in‐molecules theory. The R2Sn(L)Cl complexes were screened for their in vitro antifungal activity against chosen fungal strains.

Synthesis, spectral characterization, DFT studies, and computational screening of 4‐amino‐3‐mercapto‐5‐methyl‐1,2,4‐triazole and its cadmium(II) mixed ligands complexes as potential antimalaria drug

“…DFT predicts the ligand L 2 to potentially be tridentate coordinating through azomethine nitrogen 18N (‐N=C), the thionesulphur 31S, and naphthalynic‐O17, this has also been reported elsewhere. [ 41 ]…”

Cospatial σ-Hole and Lone Pair Interactions of Square-Pyramidal Pentavalent Halogen Compounds with π-Systems: A Quantum Mechanical Study

“…Despite being frequently called into question, − the quantum theory of atoms in molecules (QTAIM) is routinely used to visualize and quantify chemical bonding between atoms. − The theory is fundamentally based on the topological analysis of electron density. Through electron density analysis, bond paths (BPs) were identified and bond critical points (BCPs) were located.…”

Synthesis, characterization, thermal, computational and biological activity studies of new potential bioactive diorganotin (IV) nitrosubstitutedhydroxamates‐A comparative study

“…The negative magnitude of E HOMO and E LUMO are indicative of the stability of ligand and synthesized complexes. The magnitude of the HOMO‐LUMO energy gap of 0.000732 eV for ligand and 0.038507 and 0.035084 eV for (I) and (II) respectively have suggested their chemical stability, low reactivity and the resistance towards deformation of the electron cloud of chemical system under small perturbations . The computed data is thus suggestive of higher chemical stability of (I) and (II).…”