Related Experiment Video
Updated: Jun 16, 2026
Time-resolved Photophysical Characterization of Triplet-harvesting Organic Compounds at an Oxygen-free Environment Using an iCCD Camera
Published on: December 27, 2018
Tetranuclear copper(I) iodide complexes of chelating bis(1-benzyl-1H-1,2,3-triazole) ligands: structural
Gerald F Manbeck1, William W Brennessel, Christopher M Evans
1Department of Chemistry, University of Rochester, Rochester, New York 14627, USA.
Abstract:
A series of tetranuclear Cu(4)I(4)(L(n))(2) clusters (1-3) supported by the chelating 4,4'-(4,5-diX-1,2-phenylene)bis(1-benzyl-1H-1,2,3-triazole) ligands (L1, X = H; L2, X = CH(3); L3, X = F) have been prepared. Crystal structure determinations have shown that the clusters adopt a distorted "step-type" geometry in which the triazole ligands exhibit both chelating and bridging coordination modes to Cu(I) ions. When L3 was employed in a 3:2 CuI/L3 ratio, a crystalline product, 4, was obtained. Product 4 is actually a 1:1 cocrystallization of the tetranuclear cluster 3 (denoted 4a) and the dinuclear Cu(2)I(2)(L3)(2) complex (4b). X-ray structures of 1, 2, and 4 show the presence of close Cu...Cu contacts in the tetranuclear and dinuclear forms. (1)H NMR experiments indicate that rapid exchange occurs in these systems. All clusters are brightly luminescent in the solid state at 77 K and at room temperature with lambda(max) = 495-524 nm. Emission intensity decays fit a single exponential with lifetimes on the order of 10 to 35 microseconds at room temperature and 90 to 140 microseconds at 77 K. The origin of emission is tentatively assigned as a metal-to-ligand phenylene pi* charge transfer.
Related Concept Videos
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.
01:26Variables Affecting Phosphorescence and Fluorescence
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
02:42Valence Bond Theory
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...
01:18Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group with both...