Solid State Phosphorescence Enhancement of PtII-Based Emitters via Combination of π-Hole(Isocyano Group)⋅⋅⋅ dz2[PtII] and I···Cl Halogen-Bonding Interactions

Abstract

The PtII 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)⋅⋅⋅dz2[PtII] 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)⋅⋅⋅dz2[PtII] 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)⋅⋅⋅dz2[PtII] 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.

4,5-Diiodo-1-H-imidazole-derived linker ligand and Cu(i) and Co(ii) coordination polymers based thereupon

“…While keen interest in this area is mostly driven by fundamental considerations, there are also many examples demonstrating that XBs can be utilized as a tool for “fine tuning” of certain useful properties. These include (but not limited to) their application in sensors, 4–6 luminescence, 7–11 catalysis, 12–17 magnets, 18,19 etc.…”

Conformation-Associated C···dz2-PtII Tetrel Bonding: The Case of Cyclometallated Platinum(II) Complex with 4-Cyanopyridyl Urea Ligand

“…Many studies demonstrate that a solid-state supramolecular structure plays a key role in reactivity [18] and photophysics [2,[19][20][21] of such compounds. Their supramolecular organization is determined by combination of various noncovalent interaction: hydrogen bonding (HB) [22], π•••π stacking [23], metallophilic interactions [24], halogen bonding [25], chalcogen bonding [26], pnictogen [27], and tetrel bonding (abbreviated as TtB) [28,29] etc.…”