Theoretical study of the substituent effect controlling the radiative and non-radiative decay processes of platinum(ii) complexes

2017 ◽  
Vol 19 (34) ◽  
pp. 23532-23540 ◽  
Author(s):  
Wei Shen ◽  
Wenting Zhang ◽  
Chaoyuan Zhu
Keyword(s):  
Substituent Effect ◽  
Radiative Decay ◽  
Theoretical Study ◽  
Energy Gap ◽  
Organometallic Complexes ◽  
Relaxation Dynamics ◽  
Energy Gap Law ◽  
Triplet Triplet Annihilation

By taking into account the energy gap law, relaxation dynamics and triplet–triplet annihilation (TTA), six organometallic complexes are systematically investigated for possible non-radiative decay processes.

scholarly journals Inverted energy gap law for the nonradiative decay in fluorescent floppy molecules: larger fluorescence quantum yields for smaller energy gaps

2019 ◽  
Vol 6 (12) ◽  
pp. 1948-1954 ◽  
Author(s):  
Junqing Shi ◽  
Maria A. Izquierdo ◽  
Sangyoon Oh ◽  
Soo Young Park ◽  
Begoña Milián-Medina ◽  
...  
Keyword(s):  
Radiative Decay ◽  
Energy Gap ◽  
Quantum Yields ◽  
Nonradiative Decay ◽  
Fluorescence Quantum Yields ◽  
Energy Gaps ◽  
Energy Gap Law ◽  
Solution Increase ◽  
Floppy Molecules ◽  
Franck Condon

The non-radiative decay of substituted dicyano-distyrylbenzenes in solution increase with the Franck–Condon energy, being opposite to the conventional energy gap law.

The energy gap law for non-radiative decay in large molecules

1970 ◽  
Vol 1-2 ◽  
pp. 134-142 ◽  
Author(s):  
Robert Englman ◽  
Joshua Jortner
Keyword(s):  
Radiative Decay ◽  
Energy Gap ◽  
Large Molecules ◽  
Energy Gap Law

scholarly journals Multiple Resonance Deep-red Emitters with Hybridized π-bonding/ non-bonding Orbitals to Surpass the Energy Gap Law

2021 ◽  
Author(s):  
Yuewei Zhang ◽  
Dongdong Zhang ◽  
Tianyu Huang ◽  
Alexander Gillett ◽  
Yang Liu ◽  
...  
Keyword(s):  
Radiative Decay ◽  
Near Infrared ◽  
Energy Gap ◽  
Light Emitting Diode ◽  
Resonance Effect ◽  
Infrared Region ◽  
Decay Rates ◽  
Quantum Yields ◽  
Multiple Resonance ◽  
Energy Gap Law

Abstract Efficient organic emitters in the deep-red to near infrared region are rare due to the ‘energy gap law’. Here, multiple boron (B)- and nitrogen (N)-atoms embedded polycyclic heteroaromatics featuring hybridized π-bonding/ non-bonding molecular orbitals are constructed, providing a way to overcome the above luminescent boundary. The introduction of B-phenyl-B and N-phenyl-N structures enhances the electronic coupling of those para-positioned atoms, forming restricted π-bonds on the phenyl-core for delocalized excited states and thus a narrow energy gap. The mutually ortho-positioned B- and N-atoms also induce a multiple resonance effect on the peripheral skeleton for the non-bonding orbitals, creating shallow potential energy surfaces to eliminate the high-frequency vibrational quenching. The corresponding deep-red emitters with peaks at 662 nm and 692 nm exhibit narrow full-width at half-maximums of 38 nm, high radiative decay rates of ~108 s-1, ~100% photo-luminance quantum yields and record-high maximum external quantum efficiencies of >28% in a normal planar organic light-emitting diode structure, simultaneously.

scholarly journals Overcome the Energy Gap Law in Near-Infrared Emissive Aggregates via Nonadiabatic Coupling Suppression

2021 ◽  
Author(s):  
Jie Xue ◽  
Jingyi Xu ◽  
Jiajun Ren ◽  
Qingxin Liang ◽  
Qi Ou ◽  
...  
Keyword(s):  
Radiative Decay ◽  
Near Infrared ◽  
High Efficiency ◽  
Organic Materials ◽  
Energy Gap ◽  
Delayed Fluorescence ◽  
Decay Rates ◽  
Nonadiabatic Coupling ◽  
Innovative Strategy ◽  
Energy Gap Law

<p>The pursuing of purely organic materials with high-efficiency near-infrared (NIR) emissions is fundamentally limited by the large non-radiative decay rates (<i>k</i><sub>nr</sub>) governed by the energy gap law. Here, we demonstrated a feasible and innovative strategy by employing intermolecular charge-transfer (CT) aggregates (CTA) to realize high-efficiency NIR emissions via nonadiabatic coupling suppression. The formation of CTA engenders intermolecular CT in the excited states; thereby, not only reducing the electronic nonadiabatic coupling and contributing to small <i>k</i><sub>nr</sub> for high-efficiency NIR photoluminescence, but also stabilizing excited-state energies and achieving thermally activated delayed fluorescence for high-efficiency NIR electroluminescence. This work provides new insights into aggregates and opens a new avenue for organic materials to overcome the energy gap law and achieve high-efficiency NIR emissions.<br></p>

scholarly journals Overcome the Energy Gap Law in Near-Infrared Emissive Aggregates via Nonadiabatic Coupling Suppression

2021 ◽  
Author(s):  
Jie Xue ◽  
Jingyi Xu ◽  
Jiajun Ren ◽  
Qingxin Liang ◽  
Qi Ou ◽  
...  
Keyword(s):  
Radiative Decay ◽  
Near Infrared ◽  
High Efficiency ◽  
Organic Materials ◽  
Energy Gap ◽  
Delayed Fluorescence ◽  
Decay Rates ◽  
Nonadiabatic Coupling ◽  
Innovative Strategy ◽  
Energy Gap Law

<p>The pursuing of purely organic materials with high-efficiency near-infrared (NIR) emissions is fundamentally limited by the large non-radiative decay rates (<i>k</i><sub>nr</sub>) governed by the energy gap law. Here, we demonstrated a feasible and innovative strategy by employing intermolecular charge-transfer (CT) aggregates (CTA) to realize high-efficiency NIR emissions via nonadiabatic coupling suppression. The formation of CTA engenders intermolecular CT in the excited states; thereby, not only reducing the electronic nonadiabatic coupling and contributing to small <i>k</i><sub>nr</sub> for high-efficiency NIR photoluminescence, but also stabilizing excited-state energies and achieving thermally activated delayed fluorescence for high-efficiency NIR electroluminescence. This work provides new insights into aggregates and opens a new avenue for organic materials to overcome the energy gap law and achieve high-efficiency NIR emissions.<br></p>

Diffusional distortion of the free‐energy gap law

1995 ◽  
Vol 103 (18) ◽  
pp. 7927-7933 ◽  
Author(s):  
A. I. Burshtein
Keyword(s):  
Free Energy ◽  
Energy Gap ◽  
Energy Gap Law

Substituent effect on N–H bond dissociation enthalpies of carbamates: a theoretical study

2015 ◽  
Vol 93 (3) ◽  
pp. 279-288 ◽  
Author(s):  
Rupinder preet Kaur ◽  
Damanjit Kaur ◽  
Ritika Sharma
Keyword(s):  
Substituent Effect ◽  
Density Functional ◽  
Theoretical Study ◽  
Natural Bond Orbital ◽  
Stabilization Energy ◽  
Isodesmic Reactions ◽  
Bond Dissociation ◽  
Density Functional Methods ◽  
Functional Methods ◽  
Orbital Analysis

The present investigation deals with the study of the N–H bond dissociation enthalpies (BDEs) of the Y-substituted (NH2-C(=X)Y-R) and N-substituted ((R)(H)NC(=X)YH) carbamates (X, Y = O, S, Se; R = H, CH3, F, Cl, NH2), which have been evaluated using ab initio and density functional methods. The variations in N−H BDEs of these Y-substituted and N-substituted carbamates as the effect of substituent have been understood in terms of molecule stabilization energy (ME) and radical stabilization energy (RE), which have been calculated using the isodesmic reactions. The natural bond orbital analysis indicated that the electrodelocalization of the lone pairs of heteroatoms in the molecules and radicals affect the ME and RE values depending upon the type and site of substitution (whether N- or Y-). The variations in N−H BDEs depend upon the combined effect of molecule stabilization and radical stabilization by the various substituents.

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