Quinobis(imidazolylidene): synthesis and study of an electron-configurable bis(N-heterocyclic carbene) and its bimetallic complexes.

Reaction of bromanil with N,N'-dimesitylformamidine followed by deprotonation with NaN(SiMe(3))(2) afforded 1,1',3,3'-tetramesitylquinobis(imidazolylidene) (1), a bis(N-heterocyclic carbene) (NHC) with two NHC moieties connected by a redox active p-quinone residue, in 72 % yield of isolated compound. Bimetallic complexes of 1 were prepared by coupling to FcN(3) (2) or FcNCS (3; Fc=ferrocenyl) or coordination to [M(cod)Cl] (4 a or 4 b, where M=Rh or Ir, respectively; cod=1,5-cyclooctadiene). Treatment of 4 a and 4 b with excess CO(g) afforded the corresponding [M(CO)(2)Cl] complexes 5 a and 5 b, respectively.

Oxidation of poly(enetetramine)s: a new strategy for the synthesis of conjugated polyelectrolytes.

Chemical oxidation of poly(enetetramine)s was demonstrated as a new synthetic route to prepare conjugated polyelectrolytes.

Synthesis and study of differentially substituted dibenzotetraazafulvalenes.

A series of functionalized dibenzotetraazafulvalenes have been synthesized and characterized using X-ray crystallography, UV-vis spectroscopy, and cyclic voltammetry. The solid-state structures, electronic properties, and redox potentials of these compounds varied in accordance with the nature of the pendant arene substituent.

Quinone-annulated N-heterocyclic carbene-transition-metal complexes: observation of pi-backbonding using FT-IR spectroscopy and cyclic voltammetry.

A new N-heterocyclic carbene architecture comprising a 1,4-naphthoquinone annulated to 1,3-dimesitylimidazolylidene (NpQ-NHC) was synthesized in two high yielding steps from commercially available starting materials. The free NpQ-NHC was characterized (solution and solid-state) and was used to synthesize various Rh and Ag complexes that ranged in pi-electron density. Enabled by the quinone moiety, the pi-systems of these complexes were analyzed using infrared spectroscopy and cyclic voltammetry.

Dynamic covalent polymers based upon carbene dimerization.

Thermally-reversible covalent polymers featuring dynamic carbon-carbon double bonds and tunable molecular weights were prepared from difunctional carbenes; addition of transition metal complexes to these materials afforded the respective main-chain organometallic polymers.