Artem V. Semenov

The first study of the functionalization of 2‐aryl‐2 H ‐1,2,3‐triazole N ‐oxides via aryne chemistry is reported. Under optimized conditions using TBAF in DCM, various N ‐oxides react with arynes generated from o ‐silylaryl triflates to afford 2‐(2‐aryl‐2 H ‐1,2,3‐triazol‐4‐yl)phenols in moderate‐to‐excellent yields (41%–91%). Notably, N ‐oxides bearing a methoxycarbonyl group at the 4‐position undergo a subsequent intramolecular cyclization, yielding 2‐arylchromeno[3,4‐ d ][1,2,3]triazol‐4(2 H )‐ones. The latter compounds exhibit violet‐to‐blue photoluminescence with quantum yields of up to 72% in solution and up to 28% in solid state, depending on the substituent pattern. This work establishes a versatile and straightforward route to both triazolylphenols and fluorescent chromenotriazolones.

A novel approach for controlled mono- and double-insertion of sulfonamide fragments into Ni-S bonds of [Ni(S₂CNR₂)₂] complexes has been developed using aryl and alkyl sulfonyl azides as sulfonamide sources. The reaction selectivity is governed by the choice of solvent (hexafluoro-2-propanol for the monoinsertion versus isopropanol for the double-insertion) and temperature (50 and 80 °C, respectively). This method provides convenient access to previously unreported monoinsertion products [NiL(S₂CNR₂)] along with the double-insertion complexes [NiL₂] (L = NSO₂(R')S₂NR₂) under mild conditions. The scope of the reaction was demonstrated using 18 sulfonyl azides and 6 nickel(II) dithiocarbamates, affording the target complexes (38 examples) isolated in 9-97% yields. The method's practicality was confirmed through gram-scale syntheses of three representative examples (72, 76, and 92%). X-ray diffraction analysis of 15 new complexes revealed that sulfonamide fragments occupy axial positions relative to the dithiocarbamate plane, with the modified C-S bonds showing inequivalent lengths (1.76-1.78 Å for C-SN vs ∼ 1.71 Å for C-SNi). Mechanistic studies uncovered that insertion products can undergo spontaneous disproportionation in solution.

A series of 2‐nitrochalcogenocyanato(hetero)arenes were synthesized by the reaction of 2‐nitrohalo(hetero)arenes with potassium thio‐ or selenocyanate. These compounds were characterized by NMR spectroscopy, high‐resolution mass spectrometry, and X‐ray crystallography. In the obtained crystal structures, strong intramolecular Ch⋅⋅⋅O_NO2 (Ch=S, Se) chalcogen bonds between the chalcogen atom of the chalcogenocyanate moiety and the nitro group were revealed. These interactions prevent rotation of the nitro group, and thus stabilize the obtained 2‐nitrochalcogenocyanato(hetero)arenes in a distorted planar geometry. In addition, intermolecular Ch⋅⋅⋅N chalcogen bonds were observed in some structures. Both intra‐ and intermolecular interactions were studied using methods based on first‐principles and DFT approaches (e. g. QTAIM, IGMH, ELF, NBO). Two of the synthesized chalcogenocyanates namely, 4‐nitro‐5‐thiocyanatophthalonitrile (2a) and 4‐nitro‐5‐selenocyanatophthalonitrile (2b) were identified as promising supramolecular tectons for cocrystallizations with aromatic hydrocarbons, and four new cocrystals (2 a⋅PhMe, 2 a⋅o‐XylH, 2 a⋅p‐XylH, and 2 b⋅1.5(p‐XylH)) were obtained. X‐ray diffraction studies of these cocrystals demonstrated that in all cases molecules of the phthalonitrile (2 a or 2 b) and the corresponding hydrocarbon are packed into infinity columnar stacks via π⋅⋅⋅π interactions, whereas intermolecular Ch⋅⋅⋅O/N ChBs bound them to form the final supramolecular architecture.

The planar bis-chelated complex [Pd(N^∩O)₂] (1; N^∩O = 4-MeC₅H₃NNC(O)NMe₂) exhibits two distinct stacking modes with electron-deficient aromatics: π···π stacking with hexafluorobenzene (C₆F₆) versus charge-transfer π-hole interactions with 1,2,4,5-tetracyanobenzene (TCB). Cocrystallization of the complex with C₆F₆ or TCB yields cocrystals 1·3(C₆F₆) and 1·2TCB, respectively, which display different colors and stacking patterns despite similar structural motifs. Comprehensive analysis using X-ray diffraction, combined with quantum theory of atoms-in-molecules (QTAIM), an independent gradient model based on Hirshfeld partition (IGMH), extended transition state natural orbital for chemical valence theory with charge displacement function (ETS-NOCV/CDF), many-body interaction analysis, and symmetry-adapted perturbation theory (SAPT), reveals fundamentally different interaction mechanisms. In 1·3(C₆F₆), the stacking is primarily governed by intermolecular polarization without significant charge transfer, with dispersion forces contributing approximately 70% of the attractive energy. In contrast, 1·2TCB exhibits pronounced charge transfer (35 me) and significant inductive components alongside dispersion forces, characteristic of π-hole interactions. This dichotomy in stacking behavior provides new insights into the nature of organic-inorganic planar assemblies and demonstrates that seemingly similar structural patterns can arise from distinctly different combinations of noncovalent forces, which is essential for rational crystal engineering of hybrid materials.

In this work, a Pd(II)-C,N-cyclometalated complex was grafted to polysiloxanes via azide–alkyne cycloaddition. The obtained polymer–metal complex (Pd-PDMS) acts as a catalyst in the Suzuki–Miyaura reaction. Pd-PDMS was drop-casted onto a carbon fiber support, and the resulting membrane demonstrated catalytic activity in the cross-coupling reaction without yield loss after several catalytic cycles. The catalytic membrane allows for easy catalyst recycling and provides ultra-low palladium levels in Suzuki–Miyaura reaction products.

A place for M⋯O NO ₂ semicoordination was found in the entire range of interactions that occur between a NO ₂ group and metal sites.

The nucleophilic addition of 3-(4-cyanopyridin-2-yl)-1,1-dimethylurea (1) to cis-[Pt(CNXyl)₂Cl₂] (2) gave a new cyclometallated compound 3. It was characterized by NMR spectroscopy (¹H, ¹³C, ¹⁹⁵Pt) and high-resolution mass spectrometry, as well as crystallized to obtain two crystalline forms (3 and 3·2MeCN), whose structures were determined by X-ray diffraction. In the crystalline structure of 3, two conformers (3A and 3B) were identified, while the structure 3·2MeCN had only one conformer 3A. The conformers differed by orientation of the N,N-dimethylcarbamoyl moiety relative to the metallacycle plane. In both crystals 3 and 3·2MeCN, the molecules of the Pt(II) complex are associated into supramolecular dimers, either {3A}₂ or {3B}₂, via stacking interactions between the planes of two metal centers, which are additionally supported by hydrogen bonding. The theoretical consideration, utilizing a number of computational approaches, demonstrates that the C···d_z²(Pt) interaction makes a significant contribution in the total stacking forces in the geometrically optimized dimer [3A]₂ and reveals the d_z²(Pt)→π*(PyCN) charge transfer (CT). The presence of such CT process allowed for marking the C···Pt contact as a new example of a rare studied phenomenon, namely, tetrel bonding, in which the metal site acts as a Lewis base (an acceptor of noncovalent interaction).