Related Experiment Video
Updated: May 9, 2026
ARL Spectral Fitting as an Application to Augment Spectral Data via Franck-Condon Lineshape Analysis and Color Analysis
Published on: August 19, 2021
Photophysical behaviour of cyclometalated iridium(III) complexes with phosphino(terthiophene) ligands
Stephanie A Moore1, David L Davies, Marcus M Karim
1Department of Chemistry, University of British Columbia, Vancouver, BC V6 T 1Z1, Canada.
Abstract:
Six new Ir(III) complexes containing the 3'-phosphino-2,2':5',2''-terthiophene (PT3) ligand in three different coordination modes are reported. The electronic properties of the complexes are characterized by cyclic voltammetry, absorption, emission and time-resolved transient absorption spectroscopies and DFT/TDDFT calculations. The electrochemical and photophysical behaviour of the complexes was found to be dominated by the PT3 ligand. For the complexes in which the PT3 ligand is coordinated in a bidentate P,S or P,C mode, the lowest energy absorption band is attributed to π-π* PT3 localized transitions consistent with observations from DFT calculations. Emission quantum yields are low in all cases (<0.07) and emission lifetimes are short (<50 ns). Intersystem crossing leads to a long-lived triplet state ((3)L) also localized on the PT3 group. In the complex where the PT3 ligand is coordinated only via the phosphine, TDDFT calculations suggest that there is some MLCT (and Cl-PT3 CT) character in the lowest energy transition.
More Related Videos
09:45Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
12:19Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization
Published on: November 29, 2018
Related Concept Videos
01:26Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
01:14Photoluminescence: Applications
01:17Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.