Fluorescent biogenic Schiff base compounds of dimethyltin

Abstract

Fluorescent biogenic Schiff base compounds of dimethyltin featuring distinct coordination sphere in solid and solution phase.

Recent advancements of fluorescent tin(iv) complexes in biomedical molecular imaging

“…Bio conjugation of the aamino acid moieties in the ligand scaffold also helps to increase the fluorescence properties of organotin complexes. 38 A similar type of observation was also found for some organotin carboxylate complexes where the presence of more ligand units (LCOO-), an extended p-conjugated system, and the presence of more electron-donating groups altogether enhanced two-photon absorption and larger 2PA cross-section (s) values of these complexes. Also, the introduction of triphenylamine and cyano-type groups in the ligands has altered the electron distribution process.…”

“…Singh and Kaur et al discussed that a Schiff base ligand containing the aamino acid and 2-hydroxy-4-methoxy benzophenone moiety are non-fluorescent or showed negligible fluorescence before coordinating with tin metal, whereas after coordinating with tin metal, the complexes formed are highly fluorescent. 38 Flores and Pe ´rez et al also reported that after the chelation of ligands with the tin metal, fluorescence intensity, and quantum yields are strongly enhanced as compared to the ONO-donor ligands. 11 Similar types of observation were also reported by other researchers for other ONO-chelated Sn complexes, and they documented that the reason for this fluorescence enhancement is ascribed to an increase of molecular-planarity or rigidity upon the complexation, which reduces the number of non-radiative pathways.…”

“…11,37 Furthermore, the presence of different electron-withdrawing or donating groups in the ligand environment also influences the push-pull character of the imine group. 21,38 It has been reported that the introduction of cyano, nitro, and other electron-withdrawing groups into the ligand environment of tin complexes reduces fluorescence intensity and quantum yields. So, in order to enhance the fluorescence intensity, some electron-donating groups such as hydroxyl (-OH), -NEt 2 , and naphthyl groups have been introduced.…”

Highly Selective and Sensitive Dual Channel New Schiff base Chemosensor based on 5‐bromo‐2‐hydroxybenzaldehyde and its Co(II), Ni(II), Cu(II) and Zn(II) Complexes ‐ Synthesis, Spectral and Theoretical characterization and Pharmacological applications

“…[56,57] DFT analysis is carried out with respect to Mulliken Charge Analysis, HOMO -LUMO energy gap and MEP (figure 16). Quenching due to CHEQ effect [52] ≈ 8000 a.u Mulliken charge analysis proves that the electron rich centers are azomethine nitrogen and phenolic oxygen atoms. This provides evidence for the coordination of the above mentioned atoms to the metal.…”

{N-[(4-Methoxy-2-oxidophenyl)(phenyl)methylidene]glycinato}diphenylsilicon(IV)

“…Pentacoordinate silicon complexes can be generated with tridentate O,N,O 0 -chelate ligands based on Schiff bases (Wagler et al, 2014). The Schiff base {(E)-[(2-hydroxy-4methoxyphenyl)(phenyl)methylidene]amino}acetic acid has been utilized once previously to prepare a tin complex (Singh et al, 2018). The tin atom therein is coordinated to the tridentate Schiff-base ligand, two methyl groups and a methanol molecule, resulting in a hexacoordinate complex.…”