Straightforward Synthesis and Properties of Highly Fluorescent [5]- and [7]-Helical Dispiroindeno[2,1-c]fluorenes

Abstract

This work presents a general approach for synthesis of substituted [5]-helical dispiroindeno[2,1-c]fluorenes based on Rh-catalyzed intramolecular cyclotrimerization of triynes. This approach was further extended for the first synthesis of configurationally stable [7]-helical dispiroindeno[2,1-c]fluorenes.

A series of variously substituted derivatives was prepared and their photophysical and electrochemical properties were evaluated. Their fluorescence emission maxima were in the region of 351-428 nm and quantum yields up to 88 % are the highest measured among the full-carbon helical compounds.

Keywords

• alkynes
• catalysis
• cyclotrimerization
• helical compounds
• indenofluorene
• nonlinear-optical properties
• field-effect transistors
• host materials
• dihydroindenofluorene derivatives
• organic semiconductors
• spiro compounds
• solar-cells
• spirobifluorene