Aromaticity : modern computational methods and applications /
Evaluating the aromaticity of a molecular system and the influence of this concept on its properties is a crucial step in the development of novel aromatic systems.Modern computational methods can provide researchers with a high level of insight into such aromaticity, but identifying the most approp...
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| Format: | eBook |
| Language: | English |
| Published: |
Amsterdam :
Elsevier,
2021.
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| Online Access: | Connect to the full text of this electronic book |
Table of Contents:
- Cover Page
- Half Title
- Full Title
- Copyright
- Contents
- Contributors
- Foreword
- Chapter 1
- Aromaticity in molecules and transition structures: from atomic and molecular orbitals to simple ring current models
- Introduction
- Aromaticity in Hubcckel and Heilbronner-Mobius theories
- Aromaticity in SCF-MO and DFT theories
- Aromaticity and valence bond theory
- Ring currents and atomic orbitals in aromatic systems
- Summary
- Acknowledgements
- References
- Chapter 2
- Overview of the computational methods to assess aromaticity
- Introduction
- Molecular orbital-based methods
- Huckel
- Adaptive Natural Density Partitioning
- Energy-based methods
- Resonance energy
- Aromatic stabilization energy
- Isomerization stabilization energy
- Harmonic oscillator stabilization energy
- Magnetic-based methods
- Magnetic susceptibility anisotropy
- Diamagnetic susceptibility exaltation
- 1H-NMR chemical shifts
- Nucleus-independent chemical shift
- Multidimensional NICS
- Iso-chemical shielding surface
- Anisotropy of the induced current density
- Vorticity of the current density tensor
- Geometry-based methods
- Julg index (A)
- Harmonic oscillator model of aromaticity
- Bird index
- Electron delocalization methods
- Multicenter bond index
- Electron localization function
- Para-delocalization index
- Fluctuation index
- Electron density-based methods
- Ring critical point density and aromaticity
- Ellipticity index
- Shannon aromaticity
- Vibrational spectroscopy
- Conclusions
- References
- Chapter 3
- Molecular geometry as a source of electronic structure of Pi-electron systems and their physicochemical properties
- Introduction
- Bond length and its multiplicity
- Geometry-based indices of aromaticity
- The first steps
- The HOMA index
- Modifications of the HOMA index
- Applications.
- Substituent effects on aromaticity of benzenoid hydrocarbons
- Polycyclic Pi-electron alternant hydrocarbons
- Nonalternant Pi-electron hydrocarbons and their heteroanalogs
- Summary
- References
- Chapter 4
- NICS
- Nucleus-independent Chemical Shift
- Historical and physical background of NICS
- Evolution of NICS as an aromaticity index
- NICS methods for monocyclic systems
- NICS methods for polycyclic systems
- NICS methods for macrocyclic systems
- The importance of dissected NICS
- NICS beyond ^^cf^^80-systems
- How NICS compares to other indices
- Best practices for using NICS
- NICS in practice
- References
- Chapter 5
- Current density, current-density pathways, and molecular aromaticity
- Magnetic fields in quantum mechanics
- Current density
- Current-density susceptibility
- Current-density vector field
- Nuclear magnetic shielding
- Nuclear magnetic shieldings and current densities
- Magnetic susceptibilities and closed-shell paramagnetic molecules
- Treatment of the gauge origin in quantum chemistry
- The gauge-including magnetically induced current method
- Investigating current-density pathways in molecules
- Integrating the strength of the current density
- The aromatic ring-current criterion
- Aromatic pathways in polycyclic molecules
- Aromatic and antiaromatic porphyrinoids
- M^^c3^^b6bius-twisted molecules
- Carbon nanostructures
- Fullerene C60
- Gaudiene
- Toroidal carbon nanotubes
- Aluminum clusters
- Scope and limitations of the GIMIC method
- References
- Chapter 6
- Quantifying aromaticity according to the energetic criterion
- Introduction
- Resonance energy
- Aromatic stabilization energies
- The isomerization stabilization energy method
- Aromatic stabilization energies from the block-localized wave function method.
- Aromatic stabilization energies derived from energy decomposition analysis
- Quantification of aromaticity in expanded porphyrins
- Relationship between energetic indices and nonenergetic descriptors for aromaticity
- Summary
- Acknowledgments
- References
- Chapter 7
- Aromaticity descriptors based on electron delocalization
- Introduction
- Methodology
- The electron-sharing indices
- Aromaticity indices
- Geometrical aromaticity indices
- Electronic aromaticity indices
- Bond-order alternation
- Aromatic fluctuation index
- Para-delocalization index
- Iring
- Multicenter index
- Normalized versions of Iring and MCI
- AV1245 and AVmin
- Computational details
- Discussion
- Six-membered rings
- Porphyrinic systems
- C10H10 and C14H14
- Conclusions
- Acknowledgments
- References
- Chapter 8
- The electron density of delocalized bonds (EDDBs) as a measure of local and global aromaticity
- Introduction
- Electron density of delocalized bonds
- The RunEDDB program
- EDDBP as a local aromaticity descriptor
- The correlation analyses (T1 )
- The benzene distortions test
- Aromaticity changes along chemical reactions
- The performance comparison of EDDBP and IRing (T2 )
- Hückel's vs. Craig-Möbius aromaticity in metallacycles
- Visualization of global aromaticity using the EDDBG/H (r ) function
- Summary
- Acknowledgments
- References
- Chapter 9
- Conceptual density functional theory and aromaticity
- Introduction
- Conceptual density functional theory
- Reactivity descriptors
- Aromaticity and antiaromaticity
- Aromaticity descriptors
- Some applications of aromatic compounds
- Conclusions
- Acknowledgments
- References
- Chapter 10
- Antiaromatic compounds: a brief history, applications, and the many ways they escape antiaromaticity
- Introduction
- Why can't we make cyclobutadiene?.
- Antiaromaticity in cyclobutadiene: a molecular orbital analysis
- How do [4n -rings escape antiaromaticity?
- Six-interstitial aromaticity-cap-ring interactions remove antiaromaticity
- Through-space aromaticity-stacking antiaromaticity away
- Möbius aromaticity-a topological escape from antiaromaticity
- Excited-state aromaticity-reversing the Hückel rule with light
- Makeable and usable antiaromatic compounds
- References
- Chapter 11
- Cycloaromatization reactions
- Introduction-cycloaromatization reactions: making radicals without using radicals
- Unusual electronic features of cycloaromatization reactions
- Molecular orbital analysis of cycloaromatization reactions
- Ionic and zwitterionic cycloaromatizations
- Metal-catalyzed cycloaromatizations
- Five-membered heterocyclic diradicals
- Secondary aromaticity effects in cycloaromatization processes
- Aromaticity: the effect of additional aromatic rings annealed to the core
- Electronic control via direct reduction and oxidation of enediyne moiety
- Unusual electronic features of redox- and photo-activated cycloaromatizations: cyclo-RE-aromatization and activation of remote substituent effects via MO crossings
- Photochemical C1-C5 cyclization of enynes-an example of rearomatization-driven photoreaction
- Conclusions
- Acknowledgment
- References
- Chapter 12
- Baird aromaticity in excited states and open-shell ground states
- Introduction
- Theoretical derivation of Baird's rule
- Assessing excited-state aromaticity computationally
- Multidimensional character of aromaticity
- Geometric indices
- Energetic indices
- Magnetic indices
- Electronic indices
- Reactivity indices
- Illustrative applications
- Fulvenes and aromatic chameleons
- Expanded porphyrins
- Ground-state triplets
- Nonconventional aromaticity
- Concluding remarks and open challenges.
- Clarification of how Baird's rule applies to singlet states
- Monitoring aromaticity along excited-state reaction paths
- Baird aromaticity in polycyclic systems and macrocyclic systems
- References
- Chapter 13
- Global aromaticity in 2D macrocyclic polyradicaloids and 3D fully conjugated molecular cages
- Introduction
- History of aromaticity and various aromaticity rules
- Aromaticity and diradical character
- Macrocyclic polyradicaloids with global aromaticity
- Expanded porphyrinoids with radical character
- Macrocyclic polyradicaloids with Hückel's (anti )aromaticity
- Baird-type aromaticity in macrocyclic diradical/polyradical systems
- Global antiaromaticity in transition state
- 3D global aromaticity in fully conjugated diradicaloid cages
- Conclusion and outlook
- Acknowledgments
- References
- Chapter 14
- Spherical aromaticity in inorganic chemistry
- Introduction
- Adaptive natural density partitioning
- Shielding magnetic response
- Systems with S-supershell filled
- Simplest tetrahedral clusters
- Adamantane dication
- Multicenter bonding in [AuP (Bu )342+
- d-AO spherical aromaticity in Ce6O8
- Systems with P-supershell filled
- Spherical aromaticity in supertetrahedron B16F4 cluster arising from nonaromatic building blocks
- [Pd3Sn8Bi64, eight-electron spherical aromatic intermetalloid cluster
- [Sb@In8Sb123/5 and [Bi@In8Bi123/5 spherical aromatic clusters
- Charge controlled switch between amp
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- Spherical aromaticity in multilayer structures through the prism of AdNDP and magnetic criteria.