Synthesis and Optoelectronic Features of Rhodamine‐Triazole Dyads as Metallochromic Probes for Copper‐Selective Chemosensing

Abstract

Rhodamine-based chromic materials have attracted significant interest owing to their cation recognition ability with high sensitivity. However, rhodamine chromophores with controllable sensing selectivity towards transition metal species are only at the advent. Herein, three triazoleconjugated rhodamine dyads with different peripheral substituents were synthesized. The key triazole precursors required for the desired chemistry were prepared by adopting our recently developed CTAB catalyzed mechanoclick chemistry. Molecular properties derived from photo-physics, electrochemistry and surface morphology of the synthesized dyads were analyzed. Furthermore, frontier molecular orbitals, electronic structure and secondary quantum chemical parameters of dyads were also compared. Screening of dyads for their sensing ability towards an array of alkali, alkaline and transition metal ions exhibited a noticeable naked-eye detection of Cu 2 + ions and was confirmed by spectrophotometric titration. The specific binding mode of dyads as probable with Cu 2 + over other metal ions attributes to the chemoselectivity.

Synthesis and Experimental Structure of a Multifunctional Catechol‐Azomethinebenzoic Acid, DFT/DMol3 Calculations, and Molecular Docking with Hsp90

“…The so‐called chemical reactivity descriptors, which we have detailed in previous publications, [50,51] have been widely used to understand and predict the chemical behavior of compounds [52–55] . They are essentially calculated from the energies of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) using the Equations (1)–8 [50–55] …”

“…The so‐called chemical reactivity descriptors, which we have detailed in previous publications, [50,51] have been widely used to understand and predict the chemical behavior of compounds [52–55] . They are essentially calculated from the energies of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) using the Equations (1)–8 [50–55] $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {\rm Energy}\ {\rm gap}\ (E{\rm g}){\rm \char44 }\ E{\rm g}=E{_{({\rm LUMO})}}\ -\ E{_{({\rm HOMO})}}\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {\rm First}\ {\rm Ionization}\ {\rm energy}\ (E{_{{\rm I}}}){\rm \char44 }\ E{_{{\rm I}}}=-\ E{_{({\rm HOMO})}}\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {\rm Electron}\ {\rm Affinity}\ ({\rm A}){\rm \char44 }\ {\rm A}=-E{_{({\rm LUMO})}}\hfill\cr}}$$$ …”

“…The so-called chemical reactivity descriptors, which we have detailed in previous publications, [50,51] have been widely used to understand and predict the chemical behavior of compounds. [52][53][54][55] They are essentially calculated from the Experimental [a] DFT-calculated [b] Bond lengths (Å) [a] Symmetry codes: (i) -x,-y,1-z; (iii) 2-x,1-y,2-z.…”

“…energies of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) using the Equations ( 1)-( 8). [50][51][52][53][54][55] Energy gap ðEgÞ,…”

Step‐Economical Mechanosynthesis of Hybrid Azoles: Deciphering Their π‐Orbital and Pharmacological Characteristics

“…As part of our synthetic efforts in bio-active heterocyclic cores, [24][25][26][27][28][29][30][31] we envisaged the preparation of mixed azoles by encompassing click chemistry and imination in a single pot operation. Based on our mechanochemical program for sustainable synthesis, [32][33][34][35][36][37] we were particularly interested in executing this idea under ballmilling conditions. It is pertinent to mention that our group has previously demonstrated the one-jar preparation of oxindoletriazole pharmacophores via mechanochemical merger of click and Baylis-Hillman chemistry under CuO nano-catalysis (Scheme 1, top).…”