Synthesis of Bis(1,2,3-triazolyl)alkanes in Superbasic and Solvent-Free Conditions

Nucleophilic substitution reactions between 1,2,3-triazole and dibromomethane or 1,2-dirbomoethane in a superbasic medium potassium hydroxide–dimethyl sulfoxide gave mixtures of the isomeric bis(1,2,3-triazolyl)alkanes, in which (1,2,3-triazol-1-yl)(1,2,3-triazol-2-yl)alkanes and bis(1,2,3-triazol-2-yl)alkanes were the dominating products, while bis(triazol-1-yl)alkanes were detected only in trace amounts. The same products could also be obtained under solvent-free conditions in a neat reaction mixture. The proposed methods are economically feasible, do not require using toxic solvents or catalysts, and make the (1,2,3-triazol-2-yl)-derivatives, inaccessible by alkyne-azide cycloaddition (click) reactions, readily available.

Synthesis, Crystal Structure, and Luminescence of Cadmium(II) and Silver(I) Coordination Polymers Based on 1,3-Bis(1,2,4-triazol-1-yl)adamantane

Coordination polymers with a new rigid ligand 1,3-bis(1,2,4-triazol-1-yl)adamantane (L) were prepared by its reaction with cadmium(II) or silver(I) nitrates. Crystal structure of the coordination polymers was determined using single-crystal X-ray diffraction analysis. Silver formed two-dimensional coordination polymer [Ag(L)NO₃]_n, in which metal ions are linked by 1,3-bis(1,2,4-triazol-1-yl)adamantane ligands, coordinated by nitrogen atoms at positions 2 and 4 of 1,2,4-triazole rings. Layers of the coordination polymer consist of rare 18- and 30-membered {Ag₂L₂} and {Ag₄L₄} metallocycles. Cadmium(II) nitrate formed two kinds of one-dimensional coordination polymers depending on the metal-to-ligand ratio used in the synthesis. Coordination polymer [Cd(L)₂(NO₃)₂]_n was obtained in case of a 1:2 M:L ratio, while for M:L = 2:1 product {[Cd(L)(NO₃)₂(CH₃OH)]·0.5CH₃OH}_n was isolated. All coordination polymers demonstrated ligand-centered emission near 450 nm upon excitation at 370 nm.

Polymorphism of 1,3-X-adamantanes (X = Br, OH, CH3) and the crystal plastic phase formation ability

The polymorphism of 1,3-dimethyladamantane (13DMA), 1,3-adamantanediol (13DOHA) and 1,3-dibromoadamantane (13DBrA) has been studied by X-ray powder diffraction, density measurements and differential scanning calorimetry at normal and high-pressure.

Facile Synthesis of 3-(Azol-1-yl)-1-adamantanecarboxylic Acids-New Bifunctional Angle-Shaped Building Blocks for Coordination Polymers

For the first time, orthogonally substituted azole-carboxylate adamantane ligands were synthesized and used for preparation of coordination polymers. The angle-shaped ligands were prepared by the reaction of 1-adamantanecarboxylic acid and azoles (1H-1,2,4-triazole, 3-methyl-1H-1,2,4-triazole, 3,5-dimethyl-1H-1,2,4-triazole, 1H-tetrazole, 5-methyl-1H-tetrazole) in concentrated sulfuric acid. Variation of the solvent and substituents in azole rings allowed to prepare both 1D and 2D copper(II) and nickel(II) coordination polymers, [Cu₂(trzadc)₄(H₂O)_0.7]∙DMF∙0.3H₂O, [Cu(trzadc)₂(MeOH)]∙MeOH, [Ni(trzadc)₂(MeOH)₂] and [Cu₂(mtrzadc)₃(MeOH)]⁺NO₃^– (trzadc-3-(1,2,4-triazol-1-yl)-adamantane-1-carboxylic acid; mtrzadc-3-(3-methyl-1,2,4-triazol-1-yl)-adamantane-1-carboxylic acid) which were structurally characterized by single crystal X-ray diffraction. Complex [Cu(trzadc)₂(MeOH)]∙MeOH was shown to act as a catalyst in the Chan-Evans-Lam arylation reaction.