Abstract
Novel carbon-rich photochromic dihydroindolizine (DHI) derivatives substituted in the fluorene part (region A) in addition to the new spirocyclopropene 6 have been synthesized. The synthesis of dimethyl 2′,7′-diethynylspiro[cycloprop[2]ene-1,9′-fluorene]-2,3-dicarboxylate precursor 6 was accomplished in five steps, starting with the literature known conversion of fluorene to 2,7-dibromo-9H-fluoren-9-one in 56% yield over three steps. The chemical structures of the new synthesized materials have been elucidated by both analytical and spectroscopic tools. Three alterative synthetic pathways for the synthesis of DHI 9 have been established.
Highlights
Molecules that respond to the application of external stimuli by undergoing reversible transformations between two distinct structures have the potential to significantly influence the development of numerous important materials science and structural biology technologies [1, 2]
We have successfully extended the photochromism of photochromic DHI through the coupling reactions in the fluorene part
New spirocyclopropene and photochromic dihydroindolizines (DHIs) substituted in the fluorene part with acetylenic bridge for future using in electronic devices have been furnished
Summary
Molecules that respond to the application of external stimuli by undergoing reversible transformations between two distinct structures have the potential to significantly influence the development of numerous important materials science and structural biology technologies [1, 2] This potential is based on the fact that, because the molecules typically undergo dramatic changes in their electronic and topological characteristics, they can act as switching elements and other dynamic components in various optoelectronic devices and functional materials. Compounds that interconvert between different isomers having unique absorption spectra when stimulated with light are referred to as photochromic, and the process is called photochromism In these systems, the changes in the electronic patterns responsible for the changes in color result in variations in other practical physical properties such as luminescence [3], electronic conductance [4, 5], refractive index [6], optical rotation [7], and viscosity [8, 9].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
