Tuning the tautomeric behavior of tris(salicylaldimines)

2017 ◽  
Vol 15 (39) ◽  
pp. 8418-8424 ◽  
Author(s):  
S. Hessam M. Mehr ◽  
Hiroya Oshima ◽  
Veronica Carta ◽  
Brian O. Patrick ◽  
Nicholas G. White ◽  
...  
Keyword(s):  
Electron Delocalization

The tautomeric state of the versatile tris(salicylaldimine) (TSAN) motif is shown to be tunable through the electron delocalization properties of its peripheral groups.

Carbo-[3]oxocarbon and its isomers: evaluation of the stability and of the electron delocalization

2008 ◽  
Vol 10 (24) ◽  
pp. 3578 ◽  
Author(s):  
Mickaël Gicquel ◽  
Jean-Louis Heully ◽  
Christine Lepetit ◽  
Remi Chauvin
Keyword(s):  
Electron Delocalization ◽  
The Stability

scholarly journals Understanding Topological Insulators in Real Space

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2965
Author(s):  
Angel Martín Pendás ◽  
Francisco Muñoz ◽  
Carlos Cardenas ◽  
Julia Contreras-García
Keyword(s):  
Quantum Theory ◽  
Chiral Symmetry ◽  
Topological Insulator ◽  
Real Space ◽  
Electron Delocalization ◽  
Electron Localization ◽  
Visualization Tool ◽  
Atom Pairs ◽  
Chemical Concepts ◽  
Bulk Behavior

A real space understanding of the Su–Schrieffer–Heeger model of polyacetylene is introduced thanks to delocalization indices defined within the quantum theory of atoms in molecules. This approach enables to go beyond the analysis of electron localization usually enabled by topological insulator indices—such as IPR—enabling to differentiate between trivial and topological insulator phases. The approach is based on analyzing the electron delocalization between second neighbors, thus highlighting the relevance of the sublattices induced by chiral symmetry. Moreover, the second neighbor delocalization index, δi,i+2, also enables to identify the presence of chirality and when it is broken by doping or by eliminating atom pairs (as in the case of odd number of atoms chains). Hints to identify bulk behavior thanks to δ1,3 are also provided. Overall, we present a very simple, orbital invariant visualization tool that should help the analysis of chirality (independently of the crystallinity of the system) as well as spreading the concepts of topological behavior thanks to its relationship with well-known chemical concepts.

Super-bridged thiophene-based conjugated systems with enhanced π-electron delocalization, photoluminescence efficiency and stability

1998 ◽  
Vol 22 (6) ◽  
pp. 547-549 ◽  
Author(s):  
Philippe Blanchard ◽  
Hugues Brisset ◽  
Ame´de´e Riou ◽  
Rolland Hierle ◽  
Jean Roncali
Keyword(s):  
Electron Delocalization ◽  
Conjugated Systems ◽  
Photoluminescence Efficiency

Comparison of P- and As-core-modified porphyrins with the parental porphyrin: a computational study

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Aleksey E. Kuznetsov
Keyword(s):  
Computational Study ◽  
Electron Delocalization ◽  
Energy Structure ◽  
Frontier Molecular Orbitals ◽  
The Core ◽  
Potential Applications ◽  
Noticeable Reduction ◽  
Internal Electron ◽  
Porphyrin Core ◽  
Homo Lumo

Abstract The first comparative DFT (B3LYP/6-31G*) study of the Zn-porphyrin and its two derivatives, ZnP(P)4 and ZnP(As)4, is reported. For all three species studied, ZnP, ZnP(P)4 and ZnP(As)4, the singlet was calculated to be the lowest-energy structure and singlet-triplet gap was found to decrease from ca. 41—42 kcal/mol for N to ca. 17—18 kcal/mol for P and to ca. 10 kcal/mol for As. Both ZnP(P)4 and ZnP(As)4 were calculated to attain very pronounced bowl-like shapes. The frontier molecular orbitals (MOs) of the core-modified porphyrins are quite similar to the ZnP frontier MOs. For the HOMO-2 of the core-modified porphyrins due to the ZnP(P)4/ZnP(As)4 bowl-like shapes we might suppose the existence of “internal” electron delocalization inside the ZnP(P)4/ZnP(As)4 “bowls”. Noticeable reduction of the HOMO/LUMO gaps was calculated for ZnP(P)4 and ZnP(As)4, by ca. 1.10 and 1.47 eV, respectively, compared to ZnP. The core-modification of porphyrins by P and especially by As was found to result in significant decrease of the charge on Zn-centers, by ca. 0.61—0.67e for P and by ca. 0.69—0.76e for As. Charges on P- and As-centers were computed to have large positive values, ca. 0.41—0.45e and ca. 0.43—0.47e, for P and As, respectively, compared to significant negative values, ca. −0.65 to −0.66e for N. The porphyrin core-modification by heavier N congeners, P and As, can noticeably modify the structures, electronic, and optical properties of porphyrins, thus affecting their reactivity and potential applications.

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