Related Experiment Video
Updated: Feb 18, 2026
05:47
Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts
Published on: August 7, 2018
8.1K
Emission from Zeolite-Occluded Manganese-Diimine Complexes
Peter-Paul H J M Knops-Gerrits1, Frans C De Schryver2, Mark Van Der Auweraer2
1Centrum voor Oppervlaktechemie en Katalyse, Katholieke Universiteit Leuven Kardinaal Mercierlaan 92, 3001 Heverlee (Belgium) Fax: Int. code +(16)321998.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|November 28, 2017
Summary
Manganese complexes within zeolites exhibit unique luminescence properties due to matrix-induced distortions. These zeolite-encapsulated metal complexes show enhanced stability and millisecond-range decay times, unlike their solution counterparts.
Area of Science:
- Coordination Chemistry
- Materials Science
- Photochemistry
Background:
- Zeolites offer unique confined environments for synthesizing and studying metal complexes.
- Manganese complexes with bipyridine (bpy) and phenanthroline (phen) ligands are of interest for their electronic and photophysical properties.
Purpose of the Study:
- To synthesize and characterize manganese complexes within NaX, NaY, and NaEMT zeolites.
- To investigate the coordination, redox, and emission properties of these encapsulated complexes.
- To elucidate the role of the zeolite matrix in influencing the complexes' photophysical behavior.
Main Methods:
- Synthesis of manganese complexes within zeolite supercages and hypercages.
- Characterization using ESCA, CA, FT-IR, FT-Raman, diffuse reflectance, and emission spectroscopy.
- Analysis of metal-to-ligand charge transfer (MLCT) and emission properties.
Main Results:
- FT-IR/FT-Raman confirmed cis coordination and revealed steric constraints in phen complexes.
- [Mn(bpy)2 ]2+ complexes exhibited MLCT at 495 nm; broadening in [Mn(phen)2 ]2+-NaY was due to distortion.
- Zeolite-induced steric restrictions enhanced emission quantum yield and caused ipsochromic shifts.
- Matrix-induced complex distortion was identified as the key factor governing emission properties.
- Decay times for [Mn-(bpy)2 ]2+-NaY were in the millisecond range (7.5-11.5 ms).
Conclusions:
- Zeolite matrices significantly influence the coordination and photophysical properties of manganese complexes.
- Encapsulation in zeolites enhances complex stability, enabling luminescence from charge transfer states not observed in solution.
- Zeolites act as supramolecular cryptands, protecting complexes from photodissociation and promoting unique emissive behaviors.
More Related Videos
Related Concept Videos
01:21Radical Oxidation of Allylic and Benzylic Alcohols
3.0K
Activated manganese(IV) oxide can selectively oxidize allylic and benzylic alcohols via a radical intermediate mechanism. Primary allylic alcohols are oxidized to aldehydes, while secondary allylic alcohols yield ketones. The redox reaction of potassium permanganate with an Mn(II) salt such as manganese sulfate (under either alkaline or acidic conditions), followed by thorough drying, yields the oxidizing agent: activated MnO2. While MnO2 is insoluble in the solvents used for the reaction, the...
3.0K
03:02Colors and Magnetism
14.2K
Color in Coordination Complexes
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...
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...
14.2K
02:58Crystal Field Theory - Octahedral Complexes
31.1K
Crystal Field Theory
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...
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...
31.1K
02:42Valence Bond Theory
11.4K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
11.4K
02:21Oxidation of Alkenes: Syn Dihydroxylation with Potassium Permanganate
17.1K
Alkenes can be dihydroxylated using potassium permanganate. The method encompasses the reaction of an alkene with a cold, dilute solution of potassium permanganate under basic conditions to form a cis-diol along with a brown precipitate of manganese dioxide.
17.1K