Regulation of intra- and intermolecular Pt–Pt and π–π interactions of a U-shaped diplatinum complex to achieve pseudo-polymorphic emissions in solution and crystalline states. Issue 29 (12th July 2017)

• Record Type: Journal Article
• Authors: Gong, Zhong-Liang; Zhong, Yu-Wu; Yao, Jiannian
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 29(2017)
• Page Start: 7222
• Page End: 7229
• Publication Date: 2017-07-12
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7tc02282d
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Pseudo-polymorphic emissions of a U-shaped di-[Pt(NCN)] complex were achieved in crystalline and solution states by regulating the intramolecular conformation (open or closed) and intermolecular stacking mode (with or without Pt–Pt interaction). Abstract : For the purpose of developing multicolor emissive molecular materials, a U-shaped diplatinum molecular switch1 with an N, N -dimethylurea bridge was prepared. Three forms of single crystals of1 with yellow (1 A), orange (1 B), or red (1 C) emission were obtained. X-ray analysis shows that the two constituent [Pt(NCN)] units can have an open (1 A and1 C) or closed (1 B) conformation with different modes of crystal packing. In particular, intermolecular Pt–Pt interaction is evident for1 C with a short Pt–Pt distance of 3.226 Å. The interconversion among these crystals was triggered by external conditions, with the aid of an additional form of crystal1 D. The deep-red emissive crystal1 C exhibits excellent photophysical properties with λ max, emi of 650 nm, Φ of 36%, and τ of 846 ns. Spectroscopic analysis supports the hypothesis that compound1 has a dominant open conformation in CHCl3 and a closed conformation in MeOH solution. The conformational switching and the degree of intermolecular interaction with tunable emission colors can be regulated by solvent composition.