The experimental structural features of chalcogen bonding (ChB) interactions in over 34,000 linear fragments R–Ch⋯A (Ch = S, Se, Te; R = C, N, O, S, Se, Te; A = N, O, S, Se, Te, F, Cl, Br, I) were analyzed. The bond distances d_R–Ch and the interaction distances d_Ch⋯A were investigated, and the functions δ_R–Ch and δ_Ch⋯A were introduced to compare the structural data of R–Ch⋯A fragments involving different Ch atoms. The functions δ_R−Ch and δ_Ch⋯A were calculated by normalizing the differences between the relevant bond d_R–Ch and ChB interaction d_Ch⋯A distances with respect to the sum of the relevant covalent (r_covR + r_covCh) and the van der Waals (vdW) radii (r_vdWCh + r_vdWA), respectively. A systematic comparison is presented, highlighting the role of the chalcogen involved, the role of the R atoms covalently bonded to the Ch, and the role of the A species playing the role of chalcogen bond acceptor. Based on the results obtained, an innovative approach is proposed for the evaluation and categorization of the ChB strength based on structural data.

The reactions of 2,4-bis(4-methoxyphenyl)-1,3-dithio-2,4-diphosphetane-2,4-disulfide (Lawesson’s Reagent, LR) with benzylamine (BzNH₂) and 4-phenylbutylamine (PhBuNH₂) yield benzylammonium P-(4-methoxyphenyl)-N-benzyl-amidodithiophosphonate (BzNH₃)(BzNH-adtp) and 4-phenylbutylammonium P-(4-methoxyphenyl)-N-(4-phenylbutyl)-amidodithiophosphonate (PhBuNH₃)(PhBuNH-adtp). The relevant nickel complexes [Ni(BzNH-adtp)₂] and [Ni(PhBuNH-adtp)₂] and the corresponding hydrolysed derivatives (BzNH₃)₂[Ni(dtp)₂] and (PhBuNH₃)₂[Ni(dtp)₂] were prepared and fully characterized. The antimicrobial activity of the aforementioned amidodithiophosphonates against a set of Gram-positive and Gram-negative pathogen bacteria was evaluated, and [Ni(BzNH-adtp)₂] and [Ni(PhBuNH-adtp)₂] showed antiproliferative activity towards Staphylococcus aureus and Staphylococcus haemolyticus strains. density functional theory (DFT) calculations were performed to shed some light on the activity of reported compounds related to their tendency towards P–N bond cleavage.

Ammonium monoethyloxalate (AmEtOx) is proposed as a consolidanting agent for carbonate stones such as biomicritic limestone and marble, resulting in the formation of a microcrystalline passivating phase of calcium oxalate (whewellite and weddellite).

The reaction of the complex [Au(phen)Br₂](PF₆) (phen = 1,10-phenanthroline) with molecular dibromine afforded {[Au(phen)Br₂](Br₃)}_∞ (1). Single crystal diffraction analysis showed that the [Au(phen)Br₂]⁺ complex cations were bridged by asymmetric tribromide anions to form infinite zig-zag chains featuring the motif ···Au–Br···Br–Br–Br···Au–Br···Br–Br–Br···. The complex cation played an unprecedented halogen bonding (XB) donor role engaging type-I and type-II XB noncovalent interactions of comparable strength with symmetry related [Br₃]⁻ anions. A network of hydrogen bonds connects parallel chains in an infinite 2D network, contributing to the layered supramolecular architecture. DFT calculations allowed clarification of the nature of the XB interactions, showing the interplay between orbital mixing, analyzed at the NBO level, and electrostatic contribution, explored based on the molecular potential energy (MEP) maps of the interacting synthons.

The reactivity between bis(pyridin‐2‐yl)diselane ^oPy₂Se₂ and ditellane ^oPy₂Te₂ (L1 and L2, respectively; ^oPy=pyridyn‐2‐yl) and I₂/Br₂ is discussed. Single‐crystal structure analysis revealed that the reaction of L1 with I₂ yielded [(HL1⁺)(I⁻)⋅5/2I₂]_∞ (1) in which monoprotonated cations HL1⁺ template a self‐assembled infinite pseudo‐cubic polyiodide 3D‐network, while the reaction with Br₂ yielded the dibromide H^oPySe^IIBr₂ (2). The oxidation of L2 with I₂ and Br₂ yielded the compounds H^oPyTe^III₂ (3) and H^oPyTe^IVBr₄ (6), respectively, whose structures were elucidated by X‐ray diffraction analysis. FT‐Raman spectroscopy measurements are consistent with a 3c–4e description of all the X−Ch−X three‐body systems (Ch=Se, Te; X=Br, I) in compounds 2, 3, H^oPyTe^IIBr₂ (5), and 6. The structural and spectroscopic observations are supported by extensive theoretical calculations carried out at the DFT level that were employed to study the electronic structure of the investigated compounds, the thermodynamic aspects of their formation, and the role of noncovalent σ‐hole halogen and chalcogen bonds in the X⋅⋅⋅X, X⋅⋅⋅Ch and Ch⋅⋅⋅Ch interactions evidenced structurally.