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Four new crystal structures of trithiocyanuric acid (TTCA) with diazine derivatives have been determined, revealing key N–H⋯S interactions that stabilize molecular aggregates. TTCA forms two types of chains—linear and zigzag—each with distinct structural characteristics. Geometry and Hirshfeld surface analyses, supported by quantum-theoretical calculations, demonstrate that both chain arrangements are equally feasible, arising from inherent preferences in the crystal's structural organization. The critical role of intermolecular hydrogen bonds, particularly those involving amine groups as proton donors, in stabilizing these cocrystals is highlighted. To analyze the energy parameters, we applied the many-body extension of the supramolecular interaction energy approach for chain complexes in their crystal-state geometry, allowing decomposition of the interaction energy into two- and many-body contributions. The prevalent hydrogen bonding synthon, R 22 (8), which forms both linear and zigzag chain structures, was found to be crucial in stabilizing the TTCA aggregates. [ABSTRACT FROM AUTHOR]

In this work, α-tocopherol and trolox were studied as compounds that have high biological activity. α-Tocopherol is considered a food additive because the refining process of vegetable oils causes the depletion of this vitamin, and thus, its inclusion is required to keep them from oxidizing. Computational tools have determined the antioxidant activity of these additives. The geometries of the studied molecules were optimized using two density functional methods, including M05-2X and M06-2X, in combination with the 6-311++G(2d,2p) basis set. The results indicated that when comparing the antioxidant activity of α-tocopherol and trolox, they were very similar to each other, but α-tocopherol had an antioxidant activity slightly higher, around 1.2 kJ/mol, than trolox. Thus, these additives can be used as polymer additives to protect materials from free-radical-induced stress. To test their applicability in polymeric formulations, flexible polyurethane foams were prepared with varying α-tocopherol ratios and NCO indices (1.0 and 1.1). Increasing the α-tocopherol content reduced the compressive force and altered the mechanical properties, likely due to its presence in the foam structure. This additive not only fine-tuned the mechanical properties but also provided antioxidant effects, enabling multiple enhancements in polymeric products with a single additive. [ABSTRACT FROM AUTHOR]

Cocrystals of thiourea with pyrazine N‐oxide as thiourea–pyrazine N‐oxide (2/1), C4H4N2O·2CH4N2S, (I), and with phenazine as thiourea–phenazine (6/7), 7C12H8N2·6CH4N2S, (II), both crystallize in the monoclinic space group P21/c. In the crystalline state, molecules of both components are linked by N—H...N hydrogen bonds. In addition, there are R22(8) hydrogen‐bond synthons between thiourea molecules in both crystal structures. Furthermore, bifurcated hydrogen bonds between the –NH groups in the thiourea molecule and the N and O atoms in the N‐oxide ring [in (I)], as well as the N atom in the central phenazine ring [in (II)], play a significant role in both structures. This emerging motif was thoroughly examined using quantum chemistry methods. [ABSTRACT FROM AUTHOR]

We have found that amines significantly accelerate iodide substitution in CpFe(CO)2I (1) (Cp = η5-cyclopentadienyl) with phosphines and allow the synthesis of new complexes that are not available through reactions carried out without an amine. The reaction of equimolar amounts of 1 and triphenylphosphine in toluene containing DIPA afforded [CpFe(CO)2PPh3]+I− within 5 min at room temperature in 72% yield (90% after 24 h). DIPA and pyrrolidine gave the highest yields of the tested amines. We performed a similar reaction using model bisphosphines 1,3-bis(diphenylphosphino)ethane (dppe) and 1,1′-bis(diphenylphosphino)ferrocene (dppf). The products depended on the reagent ratio and bore the CpFe(CO)2 moiety coordinated to one or two phosphine phosphorus atoms. Chelates [CpFe(CO)(dppe)]+I− (4) and [Cp2Fe2(CO)4(dppe)]2+2I− (5) were formed in 72% and 98% yield, respectively. We also performed the DIPA-catalyzed reaction of 1 with triethyl phosphite and obtained the product of an Michaelis–Arbuzov-like rearrangement, CpFe(CO)2[P(O)(OCH2CH3)2] (11). All complexes were characterized with spectroscopic analysis by NMR, FT-IR, and ESI-MS, and by XRD for three complexes. To clarify the reaction mechanism, we performed theoretical calculations of the intermolecular interactions between 1 and amine molecules. We propose two possible reaction mechanisms to explain the formation of products. [ABSTRACT FROM AUTHOR]

Thiochalcones undergo cycloaddition reactions in THF solution at 60 °C with the synthetically unexplored 1-phenyl-4H-phosphinin-4-one 1-oxide in a highly regio- and stereoselective manner, yielding hitherto unknown bicyclic P,S-heterocycles containing fused thiopyran and phosphinine rings. The stereochemical structures of two of the obtained (4+2)-cycloadducts were unambiguously assigned by means of the X-ray single-crystal analysis. Based on these assignments, a concerted mechanism of the hetero-Diels–Alder reaction via the preferred endo approach of the heterodiene from the less hindered P=O side of the phosphininone molecule is postulated to explain the established rac-(4RS,8SR,9SR,10SR)-configured (4+2)-cycloadducts isolated as major products. [ABSTRACT FROM AUTHOR]

Reactions of dimethyl 2‐arylcyclopropane‐1,1‐dicarboxylates, used as representatives of D‐A cyclopropanes, with tropothione were carried out in the presence of scandium triflate as a catalyst, under mild conditions (CH2Cl2 solution, rt). The anticipated (8+3)‐cycloaddition products, cycloheptatriene fused thiopyrans, were obtained in good to excellent yields. Cycloadditions occurred with complete diastereoselectivity and in all cases single diastereomers were formed. Structures of isolated cycloadducts were established based on spectroscopic data and in two cases they were unambiguously confirmed by single crystal X‐ray diffraction analysis. In contrast to an analogous (8+3)‐cycloaddition reported for parent tropone, which was performed in the presence of Ni(ClO4)2, no 1,3‐H shift leading to products possessing a CH2 moiety located within the seven‐membered ring was observed. [ABSTRACT FROM AUTHOR]