2 research outputs found
Computational Investigation of SomeXanthene-Based Molecules for Optoelectronic Properties: DFT and TD-DFT Study
No full textIn this study, we present the design and theoretical investigation of four xanthene-based molecules such as fluorescein (F), fluorescein hydrazide (FH), 2-((4-(dimethylamino) benzylidene) amino)-3′,6′- dihydroxyspiro[isoindoline-1,9′-xanthen] 3-one (DMAB-HIX) and 2-((anthracen-9-ylmethylene) amino)-3',6'-dihydroxyspiro[isoindoline-1,9'-xanthen]-3-one (ANT-HIX) to explore the optical and electronic properties for potential application in optoelectronic devices. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were employed to evaluate frontier molecular orbitals, chemical reactivity descriptors, absorption and emission spectra, excitation binding energies, excited-state lifetime and light-harvesting efficiencies. The results reveal that molecular functionalization significantly influences the optoelectronic behaviour of the studied systems. In particular, DMAB-HIX shows a shorter excited-state lifetime, higher light-harvesting efficiency and a lower HOMO-LUMO energy gap, attributed to the strong electron-donating effect of the dimethylamino substituents (DMA). These finding establish clear structure-property relationships and suggest that DMAB-HIX shows potential as a high-performance OLED emissive material.
KEYWORDS
Optoelectronic properties; Xanthene; DFT; light-emitting; excitation energy
Conductivity-Based Gas Sensors Using Tamarindus indica Polysaccharide-Capped Gold Nanoparticles for the Detection of Volatile Gases
No full textGold nanoparticles
(nAu) were synthesized by a
sustainable approach utilizing tamarind seed polysaccharide (TSP).
Polysaccharides are naturally occurring polymers derived from tamarind
seeds, which function both as capping and reducing agents. Polyaniline
(PANI) was subsequently capped over the as-prepared gold nanoparticles
in order to facilitate the sensor property. The TSP-nAu-PANI film was fabricated by Methods I and II and utilized in the
investigation of active sensor devices for the detection of organic
pollutants such as benzene, toluene, and chloroform. The synthesized
gold nanoparticles and the TSP-nAu-PANI films were
analyzed using several analytical and spectral tools. Among the two
methods, the Method II (TSP-nAu-PANI) film has a
high sensing response toward benzene (105.69%), toluene (96.99%),
and chloroform (74.98%). TSP is also a proton-conducting biopolymer,
which enhances the conductivity of the material. The combination with
the PANI layer of the film adsorbs the vapors easily and the prepared
film material is more effective and ideal for sensing toxic gases
