Synthesis and Characterization of a Triphenyl-Substituted Radical and an Unprecedented Formation of a Carbene-Functionalized Quinodimethane

摘要

The trichlorosilylcarbene monoradical (Cy-cAACC)SiCl_3 (1) was directly converted to (Cy-cAACC)SiPh_3 (2) by substitution of the three chlorine atoms with phenyl groups without affecting the radical center adjacent to the silicon atom. In addition to the structure determination, compound 2 was studied by EPR spectroscopy and DFT calculations. The three hyperfine lines in the EPR spectrum of 2 are due to the coupling with ~(14)N nucleus. Functionalized 1,4-quinodimethane Me_2-cAAC=C_6H_4=CPh_2 (7) was isolated, whereas carbon analogue of radical 2 was targeted. Cyclic voltammogram of 7 indicated that a stable radical-anion 7C~-, as well as a radical-cation 7C~+, can be prepared. Theoretical calculations showed that one-electron ionization energy and electron affinity of 7 are 5.1 and 0.7 eVmol~(-1), respectively.