Clusterization-Induced Emission Shift in Copper(I) Thiones
Bikash Lahkar1, Dinesh Harijan1, Gopendra Muduli1
1Organometallics and Materials Chemistry Lab, Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana 502285, India.
None:
Cluster-induced luminescence depicts a significant role in light-emitting applications. The reaction between 1-isopropyl-3-(pyridine-2-yl)-benzimidazol-2-thione (L) and one equivalent of copper(I) iodide gave luminogen copper cluster, [(L)Cu(μ2-I)]2 (1). Cluster 1 is further seeded with a tetranuclear copper cluster by treating L with four equivalents of copper iodide to isolate luminogen [(L)Cu(μ2-I)]2·[(μ2-L)Cu2(μ2-I)(μ3-I)]2 (2), with unique emissive properties. The cocluster (2) consists of two distinct copper clusters [(L)Cu(μ2-I)]2 and [(μ2-L)Cu2(μ2-I)(μ3-I)]2. A redshift of Δλem = 55 nm in crystalline state emission has been observed for cocluster 2 as compared to that of cluster 1. Such variation in crystalline state emissions is due to the presence of different noncovalent interactions due to crystal packing. The optical band gaps of 2.40 eV (1) and 2.45 eV (2) have been calculated using the Tauc plot. Furthermore, to investigate the electronic properties of both clusters, DFT and TD-DFT calculations were performed. The HOMO-LUMO energy gap of 1 (3.03 eV) is considerably higher than that of 2 (2.75 eV). TD-DFT calculations revealed that the nature of emission in these clusters is a combination of 3XLCT, 3MLCT, and 3ILCT transitions. Both clusters have been coated on the surface of a commercially available 3 V LED. The emissions of the coated LEDs are similar to those of crystalline samples of pure clusters.
More Related Videos
11:04Ion Mobility-Mass Spectrometry Techniques for Determining the Structure and Mechanisms of Metal Ion Recognition and Redox Activity of Metal Binding Oligopeptides
Published on: September 7, 2019
![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
09:12[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
Published on: May 21, 2019
Related Concept Videos
01:14π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds
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...
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...
01:27π Electron Effects on Chemical Shift: Overview
01:27Inductive Effects on Chemical Shift: Overview
01:26Variables Affecting Phosphorescence and Fluorescence