GRAPHICAL ABSTRACT
ABSTRACT
A sterically crowded triarylphosphine bearing an ester group, (4-ethoxycarbonyl-2,6-diisopropylphenyl)bis(2,4,6-triisopropylphenyl)phosphine, was synthesized by the lithiation of the corresponding (bromoaryl)phosphine followed by the reaction with excess diethyl carbonate. The ester was obtained as lemon yellow crystals and exhibits the blueshifted UV-Vis absorption and fluorescence as compared with the orange-colored corresponding aldehyde and ketone. The effect of the substitution of an ester group on the photophysical and redox properties of the sterically crowded triarylphosphine is discussed, and the properties of the sterically crowded triarylphosphines bearing an aldehyde, a ketone, and an ester groups are briefly reviewed.
Acknowledgment
The authors thank Research and Analytical Center for Giant Molecules, Graduate School of Science, Tohoku University, for measuring mass spectra and performing elemental analysis.
Funding
This work was supported by JSPS KAKENHI (Grant numbers 22605001, 25600020).