Effects of Steric Constraint on Chromium(III) Complexes of Tetraazamacrocycles. 3. Insights into the Temperature-Dependent Radiationless Deactivation of the2Eg(Oh) Excited State oftrans-[Cr(N4)(CN)2]+Complexes

2006 ◽  
Vol 45 (9) ◽  
pp. 3789-3793 ◽  
Author(s):  
Michael T. Vagnini ◽  
Noel A. P. Kane-Maguire ◽  
Paul S. Wagenknecht
Keyword(s):  
Excited State ◽  
Temperature Dependent ◽  
Steric Constraint

scholarly journals Thermochromic aggregation-induced dual phosphorescence via temperature-dependent sp3-linked donor-acceptor electronic coupling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tao Wang ◽  
Zhubin Hu ◽  
Xiancheng Nie ◽  
Linkun Huang ◽  
Miao Hui ◽  
...  
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Electronic Coupling ◽  
Temperature Dependent ◽  
Molecular Systems ◽  
Donor And Acceptor ◽  
Theoretical Investigations ◽  
Donor Acceptor ◽  
And Control ◽  
Two Temperature

AbstractAggregation-induced emission (AIE) has proven to be a viable strategy to achieve highly efficient room temperature phosphorescence (RTP) in bulk by restricting molecular motions. Here, we show that by utilizing triphenylamine (TPA) as an electronic donor that connects to an acceptor via an sp3 linker, six TPA-based AIE-active RTP luminophores were obtained. Distinct dual phosphorescence bands emitting from largely localized donor and acceptor triplet emitting states could be recorded at lowered temperatures; at room temperature, only a merged RTP band is present. Theoretical investigations reveal that the two temperature-dependent phosphorescence bands both originate from local/global minima from the lowest triplet excited state (T1). The reported molecular construct serves as an intermediary case between a fully conjugated donor-acceptor system and a donor/acceptor binary mix, which may provide important clues on the design and control of high-freedom molecular systems with complex excited-state dynamics.

scholarly journals Excited-State Relaxation in Luminescent Molybdenum(0) Complexes with Isocyanide Chelate Ligands

Inorganics ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 14
Author(s):  
Patrick Herr ◽  
Oliver S. Wenger
Keyword(s):  
Excited State ◽  
Excited States ◽  
Quantum Yields ◽  
Nonradiative Relaxation ◽  
Temperature Dependent ◽  
Tert Butyl ◽  
Thermally Activated ◽  
Ligand Charge Transfer ◽  
Order Of Magnitude ◽  
Electronic Ground

Diisocyanide ligands with a m-terphenyl backbone provide access to Mo0 complexes exhibiting the same type of metal-to-ligand charge transfer (MLCT) luminescence as the well-known class of isoelectronic RuII polypyridines. The luminescence quantum yields and lifetimes of the homoleptic tris(diisocyanide) Mo0 complexes depend strongly on whether methyl- or tert-butyl substituents are placed in α-position to the isocyanide groups. The bulkier tert-butyl substituents lead to a molecular structure in which the three individual diisocyanides ligated to one Mo0 center are interlocked more strongly into one another than the ligands with the sterically less demanding methyl substituents. This rigidification limits the distortion of the complex in the emissive excited-state, causing a decrease of the nonradiative relaxation rate by one order of magnitude. Compared to RuII polypyridines, the molecular distortions in the luminescent 3MLCT state relative to the electronic ground state seem to be smaller in the Mo0 complexes, presumably due to delocalization of the MLCT-excited electron over greater portions of the ligands. Temperature-dependent studies indicate that thermally activated nonradiative relaxation via metal-centered excited states is more significant in these homoleptic Mo0 tris(diisocyanide) complexes than in [Ru(2,2′-bipyridine)3]2+.

scholarly journals Temperature dependent excited state relaxation of a red emitting DNA-templated silver nanocluster

2017 ◽  
Vol 53 (93) ◽  
pp. 12556-12559 ◽  
Author(s):  
Cecilia Cerretani ◽  
Miguel R. Carro-Temboury ◽  
Stefan Krause ◽  
Sidsel Ammitzbøll Bogh ◽  
Tom Vosch
Keyword(s):  
Excited State ◽  
Decay Time ◽  
Fluorescence Decay ◽  
Silver Nanoclusters ◽  
Temperature Dependent ◽  
Silver Nanocluster ◽  
Fluorescence Decay Time ◽  
Average Fluorescence

The average fluorescence decay time of DNA-stabilized silver nanoclusters is temperature dependent and could find applications in nanothermometry.

Temperature dependent iodide oxidation by MLCT excited states

2014 ◽  
Vol 43 (47) ◽  
pp. 17856-17863 ◽  
Author(s):  
Atefeh Taheri ◽  
Gerald J. Meyer
Keyword(s):  
Excited State ◽  
Excited States ◽  
Temperature Dependent ◽  
Iodide Oxidation ◽  
First Time

Temperature dependent excited state iodide oxidation by two heteroleptic Ru polypyridyl compounds was quantified for the first time.

Temperature-dependent water penetration in Tween20:cholesterol niosome membrane: a study using excited state prototropism of 1-naphthol

2017 ◽  
Vol 41 (16) ◽  
pp. 8270-8278 ◽  
Author(s):  
Jitendriya Swain ◽  
Jhili Mishra ◽  
Akanksha Singh ◽  
Ashok Kumar Mishra
Keyword(s):  
Excited State ◽  
Core Region ◽  
Temperature Dependent ◽  
Water Penetration

The niosomal core region remains unaffected, whereas interfacial hydration occurs with an increase in temperature.

scholarly journals Thermochromic AIE Dual Phosphorescence via Temperature-Dependent sp3-Linked Donor-Acceptor Electronic Coupling

2020 ◽  
Author(s):  
Tao Wang ◽  
Zhubin Hu ◽  
Xiancheng Nie ◽  
Linkun Huang ◽  
Hui Miao ◽  
...  
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Electronic Coupling ◽  
Triplet States ◽  
Molecular Motions ◽  
Temperature Dependent ◽  
Molecular Systems ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
And Control

<p>Aggregation-induced emission (AIE) has proven to be a viable strategy to achieve highly efficient RTP in bulk by restricting molecular motions. Here we show that by utilizing triphenylamine (TPA) as an electronic donor which connects to an acceptor via an sp3 linker, six TPA-based AIE-active RTP luminophores were obtained. Both the TPA AIE-gen and the <i>sp</i><sup>3</sup>-linkage can suppress aggregation-caused quenching. Consequently, dual phosphorescence bands emitting from localized donor and acceptor triplet states, respectively, could be recorded at lowered temperatures; at room temperature, only a single RTP band corresponding to the lowest triplet state is present, presumably due to thermally assisted electronic coupling between the two states. The reported molecular construct serves as an “intermediary case” between a fully conjugated donor-acceptor system and a do-nor/acceptor binary mix, which may provide important clues on the design and control of molecular systems with complex excited-state dynamics.<br></p>

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