Design, Synthesis and studies directed towards the photophysical properties of the polycyclic aromatic hydrocarbons
Date of Award
Master of Science (MS)
The cross conjugated molecules are also known as cruciforms, which effectively allow the HOMO-LUMO separation. The term Cruciform is used for diaxial chromophores in which the properties of the two axes can be manipulated upon suitable substitution with auxochromic substituents. Originally designed for molecular electronic applications, the discovery that these cruciforms possess a platform where Frontier Molecular Orbitals can be tuned, led to their investigative research as sensory flourophores. In the majority of organic chromophores, the HOMO and the LUMO are congruent. Thus, upon binding to an analyte both HOMO and LUMO are almost equally affected and hence large shifts in emission are not observed. However, with spatially separated donor and acceptor units the independently addressable FMOs can be used to modulate photophysical properties. Accordingly synthesis of a cross conjugated molecule having electron donor substituent on one branch and electron acceptor substituent on the other branch was undertaken and photophysical properties was studied. Synthesis of novel fluorene-containing ligands and their complexes with ruthenium and rhenium metal was also developed and the role of fluorene rings on Ruthenium bipyridine and Rhenium complexes were investigated.