A 1,3,5,7,9-pentaazanona-1,3,6,8-tetraenate (PANT) chloride platinum(II) complex (1) was obtained via the metal-mediated double coupling of 2,3-diphenylmaleimidine with both nitrile ligands in trans-[PtCl₂(NC^tBu)₂]. Compound 1 was then co-crystallized with diiodomethane forming solvate 1·½CH₂I₂. The XRD experiment reveals that this solvate displays the halogen bonds H₂C(I)–I⋯Cl–Pt and hydrogen bonds I₂C(H)–H⋯Cl–Pt, which join two complex and one CH₂I₂ molecules in a heterotrimeric supramolecular cluster. Inspection of the CCDC database reveals only one example of the halogen bond H₂C(I)–I⋯I–Pt between the CH₂I₂ molecule and metal-coordinated halide in the structure of VEMWOA. In VEMWOA, CH₂I₂ serves solely as a halogen bond donor with no hydrogen bond contribution. Results of the Hirshfeld surface analysis and DFT calculations (M06/DZP-DKH level of theory) followed by topological analysis of the electron density distribution within the formalism of Bader's theory (QTAIM method) for both 1·½CH₂I₂ and VEMWOA confirmed the formation of these weak interactions. The evaluated energies of halogen bonds involving CH₂I₂ are in the 2.2–2.8 kcal mol⁻¹ range.

A wide range of unsymmetric thioureas has been studied in reaction with N-arylmaleimides and maleic anhydride. The regioselectivity of the addition depends not only on steric factors but on both solvent polarity and type of maleic acid derivative (imide or anhydride). The general regularities have been established providing practical guidelines to control the reaction result. The unequivocal structural assignment of all products has been done using NMR spectroscopy including ¹⁵N–¹H HMBC experiments.