N-Heterocyclic carbene-stabilized nitric oxide radicals were prepared by direct addition of nitric oxide to two N-heterocyclic carbenes in solution phase. The compounds were fully characterized by X-ray crystallography and EPR. The nitric oxide moiety in the solid compounds obtained can be thermally transferred to another N-heterocyclic carbene, suggesting potential applications to NO delivery.

This work describes polyester synthesis via alternating ring-opening copolymerization of epoxides and anhydrides using a trigonal bipyramidal chromium complex containing a sterically demanding ligand.

A ruthenium bisammine complex was formed in the reaction of ruthenium 1,4-dibenzyltetraazadiene complex with primary amines at room temperature, which was a versatile precursor for the synthesis of various Ru(II) complexes through ligand exchange reactions. In the reaction with azidobenzene, ruthenium 1,4-diphenyltetraaza-1,3-diene complex was formed, while ruthenium imido complexes were given in the reaction with bulky aryl azides such as 2-azido-1,3-dimethylbenzene and 2-azido-1,3-diisopropylbenzene. The ruthenium imido complexes showed high catalytic activity in the reaction of alkyl azides with primary amines to afford N-substituted imines.

Stabilized with an N‐heterocyclic carbene ligand of the smallest steric profile, PdII(η2‐O2)(IMe)2 (IMe = 1,3‐dimethylimidazole‐2‐ylidene) was synthesized by the direct addition of dioxygen to Pd0(IMe)2. The peroxidopalladium complex with IMe, which was previously available only by computation, was characterized by IR spectroscopy and X‐ray crystallography. Moreover, its oxygen‐atom‐transfer reactivity was elucidated by studying its thermolysis in pyridine at 60 °C to yield 1,3‐dimethylimidazol‐2‐one (IMeO) and its reaction with oxygen‐atom‐transfer acceptors such as PPh3 and (Me3Si)2.

A new type of dititanium dinitrogen complex supported by a triphenolamine (TPA) ligand is reported. Analysis by single-crystal X-ray diffraction and Raman and NMR spectroscopy reveals different coordination geometries for the two titanium centers. Hence, coordination of TPA and a nitrogen ligand results in trigonal-bipyramidal geometry, while an octahedral titanium center is obtained upon additional coordination of an ethoxide generated upon C–O bond cleavage in a diethyl ether solvent molecule. The titanium complex successfully generates ammonia in the presence of an excess amount of PCy3HI and KC8 in 154% yield (per titanium atom). A titanium complex with a bulkier TPA does not form a dinitrogen complex, and mononuclear titanium dinitrogen complexes were not accessible, presumably because of the high tendency of early transition metals to form binuclear dinitrogen complexes.

A commercial cyclopentadienylrutenium dicarbonyl dimer ([CpRu­(CO)2]2) efficiently catalyzes the formation of N–H imines and carbonyl compounds simultaneously from β-hydroxy azides via C–C bond cleavage under visible light. Density functional theory calculations for the cleavage reaction support the mechanism involving chelation of alkoxy azide species and liberation of nitrogen as the driving force. The synthetic utility of the reaction was demonstrated by a new amine synthesis promoted by chemoselective allylation of imine and synthesis of isoquinoline.

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A highly sterically demanding amino triphenolate ligand was successfully synthesized, and early transition metal complexes (Ti, V, Cr, and Mn) supported by the ligand were also obtained and fully characterized.