Matrix isolation, zero-field splitting parameters, and photoreactions of septet 2,4,6-trinitrenopyrimidines

Molecular Magnets: The Synthesis and Characterization of High-Spin Nitrenes

Among all C‐, N‐, and O‐centered polyradicals, high‐spin nitrenes possess the largest magnetic anisotropy and are of considerable interest as multi‐level molecular spin systems for exploration of organic molecular magnetism and quantum information processing. Although the first representatives of quintet and septet nitrenes were obtained almost 50 years ago, the experimental and theoretical studies of these highly reactive species became possible only recently, owing to new achievements in molecular spectroscopy and computational chemistry. Meanwhile, dozens of various quintet dinitrenes and septet trinitrenes were successfully characterized by IR, UV/Vis, and EPR spectroscopy, thus providing important information about the electronic structure, magnetic properties and reactivity of these compounds.

Recent advances in chemistry of high-spin nitrenes

Experimental and theoretical studies on aromatic nitrenes bearing from three to six unpaired electrons and having quartet, quintet, sextet or septet ground spin states, published in the last 15 years are analyzed. A comparative analysis of the magnetic properties of high-spin nitrenes and all other known high-spin organic molecules is performed. Promising areas of practical application of high-spin nitrenes as molecular magnets and as qubits and qudits for quantum computations are discussed.

The bibliography includes 214 references.

EPR spectroscopy of multicomponent, multispin molecular system obtained by the photolysis of 2,4,6-triazido-3-cyano-5-fluoropyridine in solid argon

Complex multicomponent, multispin molecular system, consisting of a septet trinitrene, two quintet dinitrenes, and three triplet mononitrenes, was obtained by the photolysis of 2,4,6-triazido-3-cyano-5-fluoropyridine in solid argon. To identify these paramagnetic products, electron paramagnetic resonance spectroscopy in combination with line-shape spectral simulations and density functional theory calculations was used. The products of the photolysis was found to be triplet 2,4-diazido-3-cyano-5-fluoropyridyl-6-nitrene (D_T  = 1.000 cm^-1 , E_T  = 0), triplet 2,4-diazido-3-cyano-5-fluoropyridyl-2-nitrene (D_T  = 1.043 cm^-1 , E_T  = 0), triplet 2,6-diazido-3-cyano-5-fluoropyridyl-4-nitrene (D_T  = 1.128 cm^-1 , E_T  = 0 cm^-1 ), quintet 4-azido-3-cyano-5-fluoropyridyl-2,6-dinitrene (D_Q  = 0.211 cm^-1 , E_Q  = 0.0532 cm^-1 ), quintet 2-azido-3-cyano-5-fluoropyridyl-4,6-dinitrene (D_Q  = 0.208 cm^-1 , E_Q  = 0.0386 cm^-1 ), and septet 3-cyano-5-fluoropyridyl-2,4,6-trinitrene (D_S  = -0.1017 cm^-1 , E_S  = -0.0042 cm^-1 ) in a 38:4:7:22:14:4 ratio, respectively.

Six-Membered Aromatic Polyazides: Synthesis and Application

Aromatic polyazides are widely used as starting materials in organic synthesis and photochemical studies, as well as photoresists in microelectronics and as cross-linking agents in polymer chemistry. Some aromatic polyazides possess high antitumor activity, while many others are of considerable interest as high-energy materials and precursors of high-spin nitrenes and C₃N₄ carbon nitride nanomaterials. The use of aromatic polyazides in click-reactions may be a new promising direction in the design of various supramolecular systems possessing interesting chemical, physical and biological properties. This review is devoted to the synthesis, properties and applications of six-membered aromatic compounds containing three and more azido groups in the ring.