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1‑D “Platinum Wire” Stacking Structure Built of Platinum(II) Diimine Bis(σ-acetylide) Units with Luminescence in the NIR Region
journal contribution
posted on 2016-09-28, 16:09 authored by Jiajia Kang, Xiaoxin Zhang, Huajun Zhou, Xuqiao Gai, Ting Jia, Liang Xu, Jianjun Zhang, Yanqin Li, Jun NiA square-planar
platinum(II) complex, Pt(DiBrbpy)(CCC6H4Et-4)2 (1) (DiBrbpy = 4,4-dibromo-2,2′-bipyridine),
and crystals of its three solvated forms, namely, 1·DMSO, 1·1/2(CH3CN), and 1·1/8(CH2Cl2), were developed and characterized. 1·DMSO and 1·1/2(CH3CN) contain
quasi-dimeric and dimeric structures with luminescence in the visible
range, whereas 1·1/8(CH2Cl2) exhibits NIR luminescence at 1022 nm due to its intrinsic 1-D “platinum
wire” stacking structure with strong Pt–Pt interactions. 1·1/8(CH2Cl2) represents the first
compound based on platinum(II) diimine bis(σ-acetylide) molecular
units with the NIR luminescence beyond 1000 nm. 1 selectively
responds to DMSO and CH3CN by changing its color and luminescence
property and the three solvated forms can be reversibly converted
to each other upon exposure to corresponding solvent vapors. Their
desolvated forms, namely 1a, 1b, and 1c, obtained after heating 1·DMSO, 1·1/2(CH3CN), and 1·1/8(CH2Cl2), respectively, can also be restored to the
original solvated forms upon exposure to corresponding solvent vapors. 1a and 1b emit NIR luminescence peaked at 998
and 1018 nm respectively, suggesting indirect synthetic methods as
powerful alternatives to achieve NIR luminescence with long wavelength.
In contrast, 1c exhibits a red luminescence with a broad
unstructured emission band centered at 667 nm. All the responses to
organic solvent vapors and heating are due to the structural transformations
which result in the conversion of the lowest energy excited states
between 3MLCT/3LLCT and 3MMLCT in
solid-state as supported by time-dependent density functional theory
(TD-DFT) calculations.