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Published on: December 16, 2013
Intramolecular pi-stacking in copper(I) diketiminate phenanthroline complexes
Paul O Oguadinma1, Alexandre Rodrigue-Witchel, Christian Reber
1Département de chimie, Université de Montréal, 2900 Boul. E.-Montpetit, Montréal, QC, H3T 1J4, Canada.
Dalton Transactions (Cambridge, England : 2003)
|August 18, 2010
Summary
This study synthesized novel copper(I) phenanthroline complexes using various diketimines. Intramolecular pi-stacking interactions were observed, influencing the complexes
Area of Science:
- Organometallic Chemistry
- Coordination Chemistry
- Materials Science
Background:
- Diketiminate ligands are versatile in coordinating with metal ions.
- Copper(I) complexes with phenanthroline ligands are of interest for their photophysical properties.
Purpose of the Study:
- To synthesize and characterize novel neutral, tetracoordinated diketiminate copper(I) phenanthroline complexes.
- To investigate the structural and photophysical properties of these complexes, focusing on the role of intramolecular pi-stacking.
Main Methods:
- Synthesis of five diketimines: N,N'-dibenzyl-2-amino-4-imino-pent-2-ene (1), S,S-N,N'-di(phenylethyl)-2-amino-4-imino-pent-2-ene (2), N,N'-bis(3,4,5-trimethoxyphenylmethyl)-2-amino-4-imino-pent-2-ene (3), N,N'-bis(pentafluorophenylmethyl)-2-amino-4-imino-pent-2-ene (4), and N,N'-diisobutyl-2-amino-4-imino-pent-2-ene (5).
- Reaction of diketimines with CuOtBu in the presence of 2,9-R2-1,10-phenanthroline to form copper(I) complexes.
- X-ray crystallography for structural determination.
- UV/vis absorption spectroscopy and luminescence spectroscopy for photophysical characterization.
Main Results:
- Successful synthesis of neutral, tetracoordinated diketiminate copper(I) phenanthroline complexes.
- Crystal structures revealed intramolecular pi-stacking between phenanthroline and N-benzyl substituents in several complexes.
- UV/vis spectra showed characteristic diketiminate and MLCT transitions.
- All complexes exhibited weak luminescence in solid state and solution with short lifetimes.
Conclusions:
- Intramolecular pi-stacking interactions play a significant role in the structural and photophysical properties of these copper(I) complexes.
- These interactions appear to enhance luminescence intensities by preventing flattening distortions.
- The synthesized complexes represent a new class of luminescent copper(I) materials.
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