Diamidocarbene-Based Thiele and Tschitschibabin Hydrocarbons: Carbonyl Functionalized Kekulé Diradicaloids

Herein,
we report diamidocarbene (DAC)-based Thiele and Tschitschibabin
hydrocarbons, diradicaloids that contain four carbonyl/amido functional
groups. The impact of two different π-conjugated spacers, p-phenylene vs p,p′-biphenylene,
has been realized. The quantum chemical calculations suggest diamidocarbene
(DAC)-based Thiele hydrocarbon (p-phenylene bridged)
closed-shell singlet is the ground state, whereas for the diamidocarbene
(DAC)-based Tschitschibabin hydrocarbon (p,p′-biphenylene bridged), open-shell singlet is the
ground state. The influence of two different π-conjugated spacers
also has been reflected in their UV–vis spectra. To gain more
information on the diamidocarbene (DAC)-based Thiele and Tschitschibabin
hydrocarbons, we have also carried out cyclic voltammetry investigations
along with UV–vis–NIR-spectroelectrochemical studies
of their corresponding 2-e oxidized product.