Cyclometalated platinum(II) complexes [Pt(ppy)Cl(CNAr)] (ppy = 2-phenylpyridinato-C2,N; Ar = C6H4-2-I 1, C6H4-4-I 2, C6H3-2-F-4-I 3, and C6H3-2,4-I2 4) bearing ancillary isocyanide ligands were obtained by the bridge splitting reaction between the dimer [Pt(ppy)(mu-Cl)]2 and 2 equiv any one of the corresponding CNAr. Complex 2 was crystallized in two polymorphic forms, namely, 2I and 2II, exhibiting green (emission quantum yield of 0.5%) and orange (emission quantum yield of 12%) phosphorescence, respectively. Structure directing non-covalent contacts in these polymorphs were verified by a combination of experimental (X-ray diffraction) and theoretical methods (NCIplot analysis, combined electron localization function (ELF), and Bader quantum theory of atoms in molecules (QTAIM analysis)). A noticeable difference in the spectrum of non-covalent interactions of 2I and 2II is seen in the Pt & middot;& middot;& middot;Pt & nbsp;interactions in 2II and absence of these metallophilic contacts in 2I. The other solid luminophores, namely, 1, 3I & minus;II, 4, and 4 & middot;CHCl3, exhibit green luminescence; their structures include intermolecular C & minus;I & middot;& middot;& middot;Cl & minus;Pt halogen bonds as the structure-directing interactions. Crystals of 1, 2I, 3I, 3II, 4, and 4 & middot;CHCl3 demonstrated a reversible mechanochromic color change achieved by mechanical grinding (green to orange) and solvent adsorption (orange to green). Superscript/Subscript Available</comment

The Pt^II isocyanide complex [Pt(ppy)Cl(CNC₆H₄-C≡C-Ph)] (1, Hppy=2-phenylpyridine) was co-crystallized with 1,4-diiodotetrafluorobenzene (1,4-DITFB), yielding 1·½(1,4-DITFB) adduct. The I···Cl halogen-bonding and π-π-stacking interactions combined with the rare π-hole(isocyano group)⋅⋅⋅d_z²[Pt^II] interactions were identified via analysis of X-ray diffraction data of the co-crystals. These two types of structure-determining interactions supplemented each other, and the system of I⋯Cl and π-hole(isocyano group)⋅⋅⋅d_z²[Pt^II] contacts achieved a 1D extended ladder-type architecture. The density functional theory calculations, employing a set of computational tools, verified the role of I⋯Cl and π-hole(isocyano group)⋅⋅⋅d_z²[Pt^II] noncovalent bonds in the spectrum of noncovalent forces. The solid-state photophysical study revealed an amplification of luminescence intensity in the co-crystals, which is attributed to the suppression of the nonradiative relaxation pathways due to an increase in the rigidity of the chromophore center.

A series of cyclometalated platinum­(II) complexes bearing neutral isocyanide or acyclic diaminocarbene ancillary ligands were designed and developed. Their photophysical properties were systematically studied in different polymer systems: poly­(methyl methacrylate), polystyrene, poly­(isobornyl acrylate), and copolymers based on them. The dependence of luminescent characteristics on the concentration of the doped complex (0.5–10 wt %), composition, and properties of the polymer material was investigated as key factors for the measurement of quantum yields, excited-state lifetimes, and spectral profiles in routine studies.

Halogen bonding (HaB) serves as a directional noncovalent interaction between electrophilic halogen donors and nucleophilic acceptors. This study demonstrates the unique role of thiocyanate nitrogen as a HaB acceptor in the supramolecular assembly of transition metal complexes. Pt(II)–thiocyanate complexes featuring halogen-substituted aryl isocyanides [Pt(ppy)(SCN)(CNAr)] (ppy = 2-phenylpyridinato-C²,N; Ar = C₆H₃-2-I-4-Br 4, C₆H₃-2,4-I₂ 5, C₆H₃-2,4-Br₂ 6) were synthesized and fully characterized (HR ESIMS, IR, NMR, UV-vis, luminescence). Solution studies revealed a dynamic S/N-thiocyanate isomer equilibrium, while crystallization yielded exclusively S-coordinated solvates (4^S·CHCl₃, 5^S·CHCl₃, 6^S·MeNO₂). X-ray diffraction confirmed isomorphic structures stabilized by directional C–X⋯NCS (X = Br, I) HaBs, with the thiocyanate nitrogen acting as the preferred acceptor despite its coordination to platinum. Theoretical analyses (DFT, QTAIM, NCIplot, ELF, NBO) validated the σ-hole-driven interactions, revealing binding energies of 1.61–4.07 kcal mol⁻¹. A Cambridge Structural Database survey underscores the rarity of such N⋯X contacts in metal–thiocyanate systems compared to prevalent S⋯X interactions. These findings establish thiocyanate nitrogen as an underutilized supramolecular synthon for crystal engineering of metal–organic materials.