The combination of visible-light and tris(trimethylsilyl)silane promoting intramolecular reductive cyclization protocol for the synthesis of functionalized indolines and 2,3-dihydrobenzofurans has been developed. The transformations occur in the absence of transition metal and additional photocatalyst. In addition, quantum yield (Φ) was determined and electron paramagnetic resonance spectroscopy was performed to better understand the reaction pathway.

A structurally new heptadentate derivative of a 15-membered pyridine-based macrocycle containing two benzimidazol-2-yl-methyl N-pendant arms (L = 3,12-bis((1H-benzimidazol-2-yl)methyl)-6,9-dioxa-3,12,18-triazabicyclo[12.3.1]octadeca-1(18),14,16-triene) was synthesized and its complexes with the general formula [M(L)](ClO₄)₂·1.5CH₃NO₂ (M = Mn^II (1), Fe^II (2), Co^II (3) and Ni^II (4)) were thoroughly investigated. X-ray crystal structures confirmed that all complexes are seven-coordinate with axially compressed pentagonal bipyramidal geometry having the largest distortion for Ni^II complex 4. Fe^II, Co^II and Ni^II complexes 2, 3 and 4 show rather large magnetic anisotropy manifested by moderate to high obtained values of the axial zero-field splitting parameter D (7.9, 40.3, and −17.2 cm⁻¹, respectively). Magneto-structural correlation of the Fe^II, Co^II and Ni^II complexes with L and with previously studied structurally similar ligands revealed a significant impact of the functional group in pendant arms on the magnetic anisotropy especially that of the Co^II and Ni^II complexes and some recommendations concerning the ligand-field design important for anisotropy tuning in future. Furthermore, complex 3 showed field-induced single-molecule magnet behavior described with the Raman (C = 507 K⁻ⁿ s⁻¹ for n = 2.58) relaxation process. The magnetic properties of the studied complexes were supported by theoretical calculations, which very well correspond with the experimental data of magnetic anisotropy. Electrochemical measurements revealed high positive redox potentials for M^3+/2+ couples and high negative redox potentials for M^2+/+ couples, which indicate the stabilization of the oxidation state +II expected for the σ-donor/π-acceptor ability of benzimidazole functional groups.

Direct selective transformation of greenhouse methane (CH₄) to liquid oxygenates (methanol) can substitute energy‐intensive two‐step (reforming/Fischer–Tropsch) synthesis while creating environmental benefits. The development of inexpensive, selective, and robust catalysts that enable room temperature conversion will decide the future of this technology. Single‐atom catalysts (SACs) with isolated active centers embedded in support have displayed significant promises in catalysis to drive challenging reactions. Herein, high‐density Ni single atoms are developed and stabilized on carbon nitride (NiCN) via thermal condensation of preorganized Ni‐coordinated melem units. The physicochemical characterization of NiCN with various analytical techniques including HAADF‐STEM and X‐ray absorption fine structure (XAFS) validate the successful formation of Ni single atoms coordinated to the heptazine‐constituted CN network. The presence of uniform catalytic sites improved visible absorption and carrier separation in densely populated NiCN SAC resulting in 100% selective photoconversion of (CH₄) to methanol using H₂O₂ as an oxidant. The superior catalytic activity can be attributed to the generation of high oxidation (Ni^III═O) sites and selective C─H bond cleavage to generate •CH₃ radicals on Ni centers, which can combine with •OH radicals to generate CH₃OH.