Intramolecular Charge Transfer: Mechanism Behind Cyanide Anion Sensing of 3,5‐Diformyl–borondipyrromethene

Abstract

The synthesis of fluorescent chemosensors has remained a focus for most of the studies, but detailed mechanisms of sensing are still lacking. Density functional theory (DFT) and time dependent-density functional theory (TD-DFT) methods have been utilized to investigate the cyanide anion sensing mechanism of 3,5-diformyl-borondipyrromethene (1). The natural charges on carbons of the formyl groups of 1 indicate that these carbons are prone to nucleophilic addition. The analysis of the frontier molecular orbitals designates the first excited state (S 1 ) of 1 as a local excited state with p ! s* transition. Likewise, S 1 of 2 (the cyano form of 1) is a charge separated state, showing intramolecular charge transfer (ICT) which is responsible for inducing the fluorescence quenching in 2.[a] Dr.

Design and synthesis of hydrophobic mixed organogels with complementary hydrogen-bond donor–acceptor sites: removal of heavy metal ions Hg2+, Cd2+ and Pb2+ from aqueous solution

“…The values of l max are greater in the case of DMSO : H 2 O as compared to only DMSO, which indicates the presence of intramolecular charge transfer (ICT) within the molecules where the wavelength increases with increasing the polarity of the solvent. [55][56][57] The fluorescence intensity and wavelength were affected by the solvents system, which has been confirmed by fluorescence analysis of 0.3 mM G8GE solution in DMSO and in the solvent combinations (1 : 1) of DMSO : EA, DMSO : DMF, DMSO : MeCN, DMSO : MeOH, DMSO : EtOH and DMSO : H 2 O. In the case of polar aprotic solvents, the intensity was much higher than polar protic solvents with lower wavelengths of l max values (Fig.…”

Photoinduced enhancement of intraligand charge-transfer of a crystalline 3,3′-diindolyl(3-pyridyl)methane

“…Charge-transfer systems depend on subunits that function as electron donors and acceptors. [1][2][3][4][5][6][7][8][9][10] Efficient donor-acceptor interaction is critical to effective charge-transfer transitions. The investigation of chargetransfer in crystalline materials that exhibit responsiveness to external stimuli, such as chemicals, 11 heat, 12,13 and light [14][15][16] varying donor-acceptor interactions is still a challenge.…”

Anion Sensing by Novel Triarylboranes Containing Boraanthracene: DFT Functional Assessment, Selective Interactions, and Mechanism Demonstration

“…These techniques offer some indirect information about the molecular geometries and their photophysical properties. The density functional theory and time-dependent density functional theory (DFT/TD-DFT) methods have proved to be effective for studying the sensing mechanism of some anion fluorescent chemosensors. − Hence, DFT/TD-DFT methods have been selected as the methods of choice to comprehend the details of anion binding and overall sensing process in this paper. The existing literature clearly lacks a detailed theoretical electronic structure insight into anion sensing of TABs and hence their fluorescence mechanism for sensing.…”