Halogen Bonding to Amplify Luminescence: A Case Study Using a Platinum Cyclometalated Complex

Vasily V Sivchik; Anastasia I Solomatina; Yi-Ting Chen; Antti J Karttunen; Sergey P Tunik; Pi-Tai Chou; Igor O Koshevoy

doi:10.1002/anie.201507229

Halogen Bonding to Amplify Luminescence: A Case Study Using a Platinum Cyclometalated Complex

Angew Chem Int Ed Engl. 2015 Nov 16;54(47):14057-60. doi: 10.1002/anie.201507229. Epub 2015 Sep 25.

Authors

Vasily V Sivchik¹, Anastasia I Solomatina², Yi-Ting Chen³, Antti J Karttunen⁴, Sergey P Tunik², Pi-Tai Chou⁵, Igor O Koshevoy⁶

Affiliations

¹ Department of Chemistry, University of Eastern Finland, 80101 Joensuu (Finland).
² Department of Chemistry, St. Petersburg State University, Universitetskii pr. 26, 198504 St. Petersburg (Russia).
³ Department of Chemistry, National Taiwan University, Taipei 106 (Taiwan).
⁴ Department of Chemistry, Aalto University, 00076 Aalto (Finland).
⁵ Department of Chemistry, National Taiwan University, Taipei 106 (Taiwan). chop@ntu.edu.tw.
⁶ Department of Chemistry, University of Eastern Finland, 80101 Joensuu (Finland). igor.koshevoy@uef.fi.

PMID: 26403269
DOI: 10.1002/anie.201507229

Abstract

The cocrystallization of a weakly luminescent platinum complex [Pt(btpy)(PPh3)Cl](1) (Hbtpy=2-(2benzothienyl)pyridine; emission quantum yield Φem=0.03) with fluorinated bromo- and iodoarenes C6F6-nXn (X=Br, I; n=1, 2) results in the formation of efficient halogen-bonding (XB) interactions Pt-Cl⋅⋅⋅X-R. An up to 22-fold enhancement (Φem =0.65) in the luminescence intensity of the cocrystallized compound is detected, without a substantial change of the emission energy. Based on crystallographic, photophysical, and theoretical investigations, the contribution of the XB donors C6F6-n Xn to the amplification of luminescence intensity is attributed to the enhancement of spin-orbit coupling through the heavy-atom effect, and simultaneously to the suppression of the nonradiative relaxation pathways by increasing the rigidity of the chromophore center.

Keywords: crystal engineering; halogen bonding; luminescence; noncovalent interactions; platinum complexes.

Publication types

Research Support, Non-U.S. Gov't