Computational investigation, comparative approaches, molecular structural, vibrational spectral, non-covalent interaction (NCI), and electron excitations analysis of benzodiazepine derivatives

Computational study on novel RhCpX (X = CF3, SiF3, CCl3, SO3H) as promising catalysts in the [3 + 2] azide-alkyne cycloaddition reaction: insights into mechanistic pathways and reactivity

This computational study investigated the catalytic efficiency of novel RhCpX complexes (X = CF3, SiF3, CCl3, SO3H) in [3 + 2] azide-alkyne cycloaddition reactions via density functional theory (MN12-L/Def2-SVP). Through quantum mechanical approaches, we explore the impact of different substituents on the Cp* ligand on the mechanism, selectivity, and reactivity of these Rh-based catalysts. Non-covalent interaction (NCI) and reduced density gradient (RDG) analyses, along with frontier molecular orbital (FMO) and Hirshfeld atomic charge analyses, were utilized to assess ligand stability and catalytic performance. The results show that RhCpSO3H offers the highest stability and reactivity, favoring the formation of 1,5-disubstituted triazoles. Our findings highlight the potential of these novel RhCpX complexes as effective catalysts in synthetic and pharmaceutical applications.

Assessing the catalytic potential of novel halogen substituted carbene NHC (F, Cl, Br, I) catalysts in [3 + 2] cycloaddition reactions: A computational investigation

This study investigated the catalytic behavior of NHC-X ligands (X = F, Cl, Br, I) in cycloaddition reactions, focusing on both mononuclear and binuclear pathways. Using NCI (noncovalent interaction), RDG (reduced density gradient), ELF (electron localization function), and LOL (localized orbital locus) computational analyses, the electronic interactions and stability of the ligands were examined. The results showed that NHC-Cl exhibited the least steric hindrance and strongest transition state stabilization, making it the most efficient catalyst. NHC-F also demonstrated strong stabilization, particularly in the binuclear pathway. In contrast, NHC-Br showed moderate efficiency, whereas NHC-I was the least effective owing to higher Gibbs free energy values and greater steric hindrance, especially in polar solvents such as water and acetonitrile. This study emphasizes the crucial role of solvent effects and thermodynamic factors in influencing the catalytic efficiency. These findings provide a framework for optimizing NHC-based catalysts for chemical transformations.