Iridium(III) Complexes with Fluorinated Phenyl-tetrazoles as Cyclometalating Ligands: Enhanced Excited-State Energy and Blue Emission

被引:14
作者
Baschieri, Andrea [2 ]
Sambri, Letizia [1 ]
Mazzanti, Andrea [1 ]
Carlone, Armando [2 ]
Monti, Filippo [3 ]
Armaroli, Nicola [3 ]
机构
[1] Univ Bologna, Dipartimento Chim Ind Toso Montanari, I-40136 Bologna, Italy
[2] Univ Aquila, Dipartimento Sci Fis & Chim, I-67100 Laquila, Italy
[3] CNR, Ist Sintesi Organ & Fotoreatt, I-40129 Bologna, Italy
关键词
TRANSITION-METAL-COMPLEXES; ANCILLARY LIGAND; PHOTOPHYSICAL PROPERTIES; PHOTOCHEMICAL PROPERTIES; DENSITY FUNCTIONALS; QUANTUM YIELDS; BEARING; SUBSTITUTION; INSIGHTS;
D O I
10.1021/acs.inorgchem.0c01995
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
Five cationic iridium(III) complexes with fluorinated cyclometalating tetrazole ligands [Ir(dfptrz)(2)L](+), where Hdfptrz = 5-(2,4-difluorophenyl)-2-methyl-2H-tetrazole and L = 2,2'-bypiridine (1F), 4,4'-ditert-butyl-2,2'-bipyridine (2F), 1,10-phenantroline (3F), 4,4'-bis(dimethylamino)-2,2'-bipyridine (4F), and tert-butyl isocyanide (5F), were prepared following a one-pot synthetic strategy based on a bis-cyclometalated solvato complex obtained via silver(I)-assisted cyclometalation, which was then reacted with the proper ancillary ligand to get the targeted complexes. The X-ray crystal structures of 2F and 4F were determined, showing that the tetrazole ligands are in a trans arrangement with respect to the iridium center. Electrochemical and photophysical properties, along with density functional theory calculations, allowed a full rationalization of the electronic properties of 1F-5F. In acetonitrile solution at 298 K, complexes 1F-3F, equipped with bipyridine and phenanthroline ligands, exhibit strong vibronically structured luminescence bands in the blue region with photoluminescence quantum yields (PLQYs) in the range 56-76%. This behavior is radically different from the nonfluorinated analogues reported previously, which emits in the green region from (MLCT)-M-3 excited states. 4F shows relatively strong emission (PLQY = 40%) of charge transfer character centered on the amino-bipyridine ancillary ligand, whereas the emission of 5F is very weak (PLQY = 0.6%), further blue-shifted and attributed to the lowest ligand-centered (3LC) triplet state of the tetrazolyl cyclometalated moiety. A similar photophysical behavior is observed in PMMA at 298 K, whereas in a 77 K matrix, all of the compounds are strong emitters. This novel fluorinated phenyl-tetrazole cyclometalating ligand provides the corresponding iridium(III) complexes with a combination of excited-state energy and redox potentials that make them very promising as photoredox catalysts.
引用
收藏
页码:16238 / 16250
页数:13
相关论文
共 65 条
[1]   The calculations of excited-state properties with Time-Dependent Density Functional Theory [J].
Adamo, Carlo ;
Jacquemin, Denis .
CHEMICAL SOCIETY REVIEWS, 2013, 42 (03) :845-856
[2]   Tuning the photophysical properties of cationic iridium(III) complexes containing cyclometallated 1-(2,4-difluorophenyl)-1H-pyrazole through functionalized 2,2′-bipyridine ligands: blue but not blue enough [J].
Baranoff, Etienne ;
Bolink, Henk J. ;
Constable, Edwin C. ;
Delgado, Manuel ;
Haeussinger, Daniel ;
Housecroft, Catherine E. ;
Nazeeruddin, Mohammad K. ;
Neuburger, Markus ;
Orti, Enrique ;
Schneider, Gabriel E. ;
Tordera, Daniel ;
Walliser, Roche M. ;
Zampese, Jennifer A. .
DALTON TRANSACTIONS, 2013, 42 (04) :1073-1087
[3]   Cyclometalated Iridium(III) Complexes Based on Phenyl-Imidazole Ligand [J].
Baranoff, Etienne ;
Fantacci, Simona ;
De Angelis, Filippo ;
Zhang, Xianxi ;
Scopelliti, Rosario ;
Graetzel, Michael ;
Nazeeruddin, Md. Khaja .
INORGANIC CHEMISTRY, 2011, 50 (02) :451-462
[4]   Introducing a New Family of Biotinylated Ir(III)-Pyridyltriazole Lumophores: Synthesis, Photophysics, and Preliminary Study of Avidin-Binding Properties [J].
Baschieri, Andrea ;
Muzzioli, Sara ;
Fiorini, Valentina ;
Matteucci, Ella ;
Massi, Massimiliano ;
Sambri, Letizia ;
Stagni, Stefano .
ORGANOMETALLICS, 2014, 33 (21) :6154-6164
[5]   Phenyl-1H-[1,2,3]triazoles as New Cyclometallating Ligands for Iridium(III) Complexes [J].
Beyer, Beatrice ;
Ulbricht, Christoph ;
Escudero, Daniel ;
Friebe, Christian ;
Winter, Andreas ;
Gonzalez, Leticia ;
Schubert, Ulrich S. .
ORGANOMETALLICS, 2009, 28 (18) :5478-5488
[6]   Near-Quantitative Internal Quantum Efficiency in a Light-Emitting Electrochemical Cell [J].
Bolink, Henk J. ;
Coronado, Eugenio ;
Costa, Ruben D. ;
Lardies, Nora ;
Orti, Enrique .
INORGANIC CHEMISTRY, 2008, 47 (20) :9149-9151
[7]   Transition-metal phosphors with cyclometalating ligands: fundamentals and applications [J].
Chi, Yun ;
Chou, Pi-Tai .
CHEMICAL SOCIETY REVIEWS, 2010, 39 (02) :638-655
[8]   Ligand-Based Charge-Transfer Luminescence in Ionic Cyclometalated Iridium(III) Complexes Bearing a Pyrene-Functionalized Bipyridine Ligand: A Joint Theoretical and Experimental Study [J].
Constable, Edwin C. ;
Neuburger, Markus ;
Roesel, Pirmin ;
Schneider, Gabriel E. ;
Zampese, Jennifer A. ;
Housecroft, Catherine E. ;
Monti, Filippo ;
Armaroli, Nicola ;
Costa, Ruben D. ;
Orti, Enrique .
INORGANIC CHEMISTRY, 2013, 52 (02) :885-897
[9]   Time-dependent density functional theory for molecules in liquid solutions [J].
Cossi, M ;
Barone, V .
JOURNAL OF CHEMICAL PHYSICS, 2001, 115 (10) :4708-4717
[10]   Luminescent Ionic Transition-Metal Complexes for Light-Emitting Electrochemical Cells [J].
Costa, Ruben D. ;
Orti, Enrique ;
Bolink, Henk J. ;
Monti, Filippo ;
Accorsi, Gianluca ;
Armaroli, Nicola .
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 2012, 51 (33) :8178-8211