Synthesis and Characterization of Metallapentalenoxazetes from the [2+2] Cycloaddition of Metallapentalynes with Nitrosoarenes

The cycloaddition reactions of carbynes in metallacycles with π-bond substrates have been rarely reported. We report the first [2+2] cycloaddition of metallapentalynes with nitrosoarenes to give the first metallapentalenoxazetes, which photophysical and electrochemical properties were studied using UV-Vis spectroscopy and cyclic voltammetry with the help of theoretical calculations.