Premium
Stepwise Strategy to Cyclometallated Pt II Complexes with N‐Heterocyclic Carbene Ligands: A Luminescence Study on New β‐Diketonate Complexes
Author(s) -
Fuertes Sara,
García Hector,
Perálvarez Mariano,
Hertog Wim,
Carreras Josep,
Sicilia Violeta
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201404915
Subject(s) - acetylacetone , carbene , chemistry , ligand (biochemistry) , luminescence , ring (chemistry) , medicinal chemistry , iodide , stereochemistry , crystallography , catalysis , inorganic chemistry , materials science , organic chemistry , biochemistry , receptor , optoelectronics
Abstract The imidazolium salt 3‐methyl‐1‐(naphthalen‐2‐yl)‐1 H ‐imidazolium iodide ( 2 ) has been treated with silver(I) oxide and [{Pt(μ‐Cl)(η 3 ‐2‐Me‐C 3 H 4 )} 2 ] (η 3 ‐2‐Me‐C 3 H 4 =η 3 ‐2‐methylallyl) to give the intermediate N‐heterocyclic carbene complex [PtCl(η 3 ‐2‐Me‐C 3 H 4 )(H $\widehat{CC}$ *‐κC*)] ( 3 ) (H $\widehat{CC}$ *‐κC*=3‐methyl‐1‐(naphthalen‐2‐yl)‐1 H‐ imidazol‐2‐ylidene). Compound 3 undergoes regiospecific cyclometallation at the naphthyl ring of the NHC ligand to give the five‐membered platinacycle compound [{Pt(μ‐Cl)( $\widehat{CC}$ *)} 2 ] ( 4 ). Chlorine abstraction from 4 with β‐diketonate Tl derivatives rendered the corresponding neutral compounds [Pt( $\widehat{CC}$ *)(L‐ O , O′ )] {L=acac (HL=acetylacetone) 5 , phacac (HL=1,3‐diphenyl‐1,3‐propanedione) 6 , hfacac (HL=hexafluoroacetylacetone) 7 }. All of the compounds ( 3 – 7 ) were fully characterized by standard spectroscopic and analytical methods. X‐ray diffraction studies were performed on 5 – 7 , revealing short PtPt and π–π interactions in the solid‐state structure. The influence of the R‐substituents of the β‐diketonate ligand on the photophysical properties and the use of the most efficient emitter, 5 , as phosphor converter has also been studied.