Phosphorescent Chiral Cationic Binuclear Iridium(III) Complexes: Boosting the Circularly Polarized Luminescence Brightness.

We report the synthesis and characterization of two chiral binuclear iridium(III) complexes ( and ) prepared from enantiopure building blocks [μ-Cl(Δ-Ir(C^N))] and [μ-Cl(Λ-Ir(C^N))]. These building blocks have been obtained by chiral preparative high-performance liquid chromatography of the neutral iridium(III) complex (piv = 2,2,6,6-tetramethylheptane-3,5-dionate) followed by selective degradation of the ancillary ligand. For comparison purposes, we also synthesized a monomer () and a dimer (, mixture).

Investigating the formation of metal nitride complexes employing a tetradentate bis-carbene bis-phenolate ligand.

The synthesis of Mn and Cr nitride complexes of a pro-radical tetradentate bis-phenol bis-N-heterocyclic carbene ligand H2LC2O2 was investigated. Employing either azide photolysis of the Mn precursor complex MnLC2O2(N3) or a nitride exchange reaction between MnLC2O2(Br) and the nitride exchange reagent Mnsalen(N) failed to provide a useful route to the target nitride MnLC2O2(N). Experimental results support initial formation of the target nitride MnLC2O2(N), however, the nitride rapidly inserts into a Mn-C bond.

Tuning the Coordination Environment of Ru(II) Complexes with a Tailored Acridine Ligand.

A novel tridentate ligand featuring an acridine core and pyrazole rings, namely 2,7- di-butyl-4,5-di(pyrazol-1-yl)acridine, , was designed and used to create two ruthenium(II) complexes: [Ru](PF) and [Ru(tpy)](PF). Surprisingly, the ligand adopted different coordination modes in the complexes: facial coordination for the homoleptic complex and meridional coordination for the heteroleptic complex. The electronic absorption and electrochemical properties were evaluated.

Chromium-Thiolate Complex Undergoing C-S Bond Cleavage.

The cleavage of C-S bonds represents a crucial step in fossil fuel refinement to remove organosulfur impurities. Efforts are required to identify alternatives that can replace the energy-intensive hydrodesulfurization process currently in use. In this context, we have developed a series of bis-thiolato-ligated Cr complexes supported by the L ligand (L = 2,2'-bipyridine-6,6'-diyl(bis(1,1-diphenylethanethiolate), one of them displaying desulfurization of one thiolate of the ligand under reducing and acidic conditions at ambient temperature and atmospheric pressure.

Interactions of Phenylalanine Derivatives with Human Tyrosinase: Lessons from Experimental and Theoretical tudies.

The pigmentation of the skin, modulated by different actors in melanogenesis, is mainly due to the melanins (protective pigments). In humans, these pigments' precursors are synthetized by an enzyme known as tyrosinase (TyH). The regulation of the enzyme activity by specific modulators (inhibitors or activators) can offer a means to fight hypo- and hyper-pigmentations responsible for medical, psychological and societal handicaps.