Experimental and theoretical investigation of optical properties on cyanostyrene based donor acceptor systems

Abstract

Luminescent materials based on zr-conjugated molecules have gained significant attentionowing to their unique photophysical properties and the tunability of these properties throughstructural modulation. Majority of the luminophores of this class are highly emissive in thesolution state while weakly emissive or non-emissive in the solid state. In this context themolecules showing aggregation induced emission found relevant for various solid state lightingapplications. Among various molecules showing aggregation induced emission properties, themolecules based on intramolecular charge transfer (ICT) are found strongly emissive in bothsolution state and solid state. In this scenario the design and synthesis oforganic rc-conjugatedmolecules showing ICT is relevant due to their scope for active component in variousoptoelectronic devices and sensors with switchable photoluminescence. However, there areseveral strategies have emerged towards the design and synthesis of D-zr-A systems withintense photoluminescence, a detailed experimental and theoretical structure-propertycorrelation is necessary towards the design of molecules with enhanced photoluminescenceand its multimode switching. Herein, this thesis pertains to the design and sl,nthesis ofcyanostyrene based organic fluorophores with strong emission and multi-stimuli responsivenature. This work details the synthesis of novel anthracene-cyanostilbene D-rc-A compounds,and their structural and optoelectronic properties. The structure-property correlations areexamined through structural data obtained from X-ray diffraction in conjunction with densityfunctional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations.Furthermore, a systematic comparative theoretical study using the DFT method was undertakenin u and B cyanostilbene derivatives to model the non-linear optical properties of thesemolecules. This thesis elaborate a promising and rational strategy towards the design ofmolecules with potential for applications in organic optoelectronics and sensing.