The Role of Substituent Effects in Tuning Metallophilic Interactions and Emission Energy of Bis-4-(2-pyridyl)-1,2,3-triazolatoplatinum(II) Complexes

M R Ranga Prabhath; Julia Romanova; Richard J Curry; S Ravi P Silva; Peter D Jarowski

doi:10.1002/anie.201502390

The Role of Substituent Effects in Tuning Metallophilic Interactions and Emission Energy of Bis-4-(2-pyridyl)-1,2,3-triazolatoplatinum(II) Complexes

Angew Chem Int Ed Engl. 2015 Jun 26;54(27):7949-53. doi: 10.1002/anie.201502390. Epub 2015 May 26.

Authors

M R Ranga Prabhath¹, Julia Romanova¹, Richard J Curry¹, S Ravi P Silva¹, Peter D Jarowski²

Affiliations

¹ University of Surrey, Advanced Technology Institute, Guildford, GU2 7XH (UK).
² University of Surrey, Advanced Technology Institute, Guildford, GU2 7XH (UK). p.d.jarowski@surrey.ac.uk.

PMID: 26015153
DOI: 10.1002/anie.201502390

Abstract

The photoluminescence spectra of a series of 5-substituted pyridyl-1,2,3-triazolato Pt(II) homoleptic complexes show weak emission tunability (ranging from λ=397-408 nm) in dilute (10(-6) M) ethanolic solutions at the monomer level and strong tunability in concentrated solutions (10(-4) M) and thin films (ranging from λ=487-625 nm) from dimeric excited states (excimers). The results of density functional calculations (PBE0) attribute this "turn-on" sensitivity and intensity in the excimer to strong Pt-Pt metallophilic interactions and a change in the excited-state character from singlet metal-to-ligand charge transfer ((1)MLCT) to singlet metal-metal-to-ligand charge transfer ((1)MMLCT) emissions in agreement with lifetime measurements.

Keywords: charge transfer; density functional calculations; photoluminescence; platinum; stacking interactions.