Physics:Quantum chemical bond

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Short description: Quantum-mechanical association of atoms into molecules and matter


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Chemical bond is the association of atoms or ions into molecules, crystals, metals, and other forms of matter. In quantum physics, bonding is explained by the behavior of electrons, their wavefunctions, and the allowed atomic orbitals and molecular orbitals.

A chemical bond may result from electrostatic attraction between oppositely charged ions, as in ionic bonding, or from the sharing and delocalization of electrons, as in covalent and metallic bonding. In a quantum description, constructive wavefunction interference can stabilize two nuclei by forming a lower-energy electronic state.[1] The equilibrium bond distance reflects a balance between attractive and repulsive interactions that can be treated quantitatively by quantum theory.[2][3]

Covalent bonding in hydrogen can be described by electron sharing in a bonding orbital.

Quantum description

All chemical bonds can be described by quantum mechanics, although simplified models remain useful in chemistry. The electron density in a bond is not simply assigned to one atom; it may be shared, polarized, or delocalized across several atoms. Models such as the octet rule and VSEPR are useful approximations, while more advanced descriptions include valence bond theory, molecular orbital theory, orbital hybridization, resonance, and ligand field theory.[4][5][6][7]

Main types of chemical bonds

Covalent bond

In a covalent bond, two or more atoms share valence electrons. A single bond shares one electron pair, while double and triple bonds share two and three electron pairs. In quantum terms, the shared electrons occupy bonding states whose spatial distribution lowers the energy of the combined system. The stability of the hydrogen molecule, for example, can be understood in terms of electron delocalization and the resulting change in kinetic and potential energy.[8][9]

Covalent bonding is central to molecules, polymers, organic compounds, and network solids such as diamond and quartz. Non-polar covalent bonds have small electronegativity differences, while polar covalent bonds have unequal electron sharing and partial charge separation.[10]

Ionic bond

In an ionic bond, electrons are transferred so that one atom becomes a positive ion and another becomes a negative ion. The attraction is mainly electrostatic. Ionic bonding is common in salts such as sodium chloride. An electronegativity difference above about 1.7 is often treated as strongly ionic, while smaller differences are more covalent in character.[11]

Metallic bonding

In metallic bonding, electrons are delocalized over a lattice of metal atoms. This collective electron behavior explains metallic properties such as electrical conductivity, thermal conductivity, ductility, tensile strength, and luster.

Coordinate covalent bond

A coordinate covalent bond is a covalent bond in which both shared electrons originate from the same atom. Such bonds occur in Lewis acid-base adducts and transition-metal complexes.

History

Early chemical theory developed before atoms were fully understood. Robert Boyle, Antoine Lavoisier, Joseph Proust, Humphry Davy, Jöns Jakob Berzelius, Edward Frankland, August Kekulé, A. S. Couper, Alexander Butlerov, Hermann Kolbe, and Richard Abegg contributed to ideas about elements, compounds, valency, and chemical combination.[12][13][14][15][16][17]

The nuclear atom and the role of electrons became clearer through the work of Hantaro Nagaoka, Ernest Rutherford, Max Planck, and Niels Bohr.[18][19][20]

In 1916 Gilbert N. Lewis introduced the electron-pair bond model, while Walther Kossel developed an ionic bonding model. Bohr also proposed an early model of chemical bonding.[21][22][23]

In 1927 Øyvind Burrau gave a quantum treatment of the hydrogen molecular ion, and Walter Heitler and Fritz London developed the approach that became valence bond theory.[24][25] Molecular orbital theory, LCAO methods, and later density functional theory became major tools in quantum chemistry.[26]

Bond energies and lengths

Strong chemical bonds are intramolecular forces that hold atoms together in molecules and solids. Their lengths and energies vary by element, bond order, and chemical environment. Typical bond energy tables are useful approximations for comparing bond strengths.[27]

Intermolecular bonding

Chemical bonding also includes weaker interactions between molecules. Van der Waals forces include interactions between partial charges and repulsions between closed electron shells.[28] Keesom forces act between permanent dipoles, London dispersion forces arise from induced dipoles, and hydrogen bonds occur when a hydrogen atom bound to an electronegative atom interacts with a lone pair on another electronegative atom.[28]: 701 [28]: 702 [28]: 703 [28]: 705-6 

Theories of chemical bonding

In pure ionic bonding, the force between atoms can be approximated by electrostatic attraction between ions. Covalent bonds require quantum-mechanical descriptions such as valence bond theory and molecular orbital theory. Valence bond theory emphasizes localized electron pairs and orbital overlap, while molecular orbital theory treats electrons as occupying orbitals delocalized over the molecule. These approaches are complementary and are both used in modern quantum chemistry. Polar covalent bonds form an intermediate case between covalent and ionic bonding.[29]

See also

Table of contents (176 articles)

Index

Full contents

1. Foundations (11)↑
  1. Physics:Quantum basics
  2. Physics:Quantum Postulates
  3. Physics:Quantum Hilbert space
  4. Physics:Quantum Observables and operators
  5. Physics:Quantum mechanics
  6. Physics:Quantum mechanics measurements
  7. Physics:Quantum state
  8. Physics:Quantum system
  9. Physics:Quantum superposition
  10. Physics:Quantum probability
  11. Physics:Quantum Mathematical Foundations of Quantum Theory
2. Conceptual and interpretations (13)↑
  1. Physics:Quantum Interpretations of quantum mechanics
  2. Physics:Quantum Wave–particle duality
  3. Physics:Quantum Complementarity principle
  4. Physics:Quantum Uncertainty principle
  5. Physics:Quantum Measurement problem
  6. Physics:Quantum Bell's theorem
  7. Physics:Quantum Hidden variable theory
  8. Physics:Quantum nonlocality
  9. Physics:Quantum contextuality
  10. Physics:Quantum Darwinism
  11. Physics:Quantum A Spooky Action at a Distance
  12. Physics:Quantum A Walk Through the Universe
  13. Physics:Quantum The Secret of Cohesion and How Waves Hold Matter Together
3. Mathematical structure and systems (13)↑
  1. Physics:Quantum Density matrix
  2. Physics:Quantum Exactly solvable quantum systems
  3. Physics:Quantum Formulas Collection
  4. Physics:Quantum A Matter Of Size
  5. Physics:Quantum Symmetry in quantum mechanics
  6. Physics:Quantum Angular momentum operator
  7. Physics:Quantum Runge–Lenz vector
  8. Physics:Quantum Approximation Methods
  9. Physics:Quantum Matter Elements and Particles
  10. Physics:Quantum Dirac equation
  11. Physics:Quantum Klein–Gordon equation
  12. Physics:Quantum pendulum
  13. Physics:Quantum configuration space
4. Atomic and spectroscopy (14)↑
    Quantum atomic structure and spectroscopy: orbitals, energy levels, and emission and absorption spectra.
  1. Physics:Quantum Atomic structure and spectroscopy
  2. Physics:Quantum Hydrogen atom
  3. Physics:Quantum number
  4. Physics:Quantum Multi-electron atoms
  5. Physics:Quantum Fine structure
  6. Physics:Quantum Hyperfine structure
  7. Physics:Quantum Isotopic shift
  8. Physics:Quantum defect
  9. Physics:Quantum Zeeman effect
  10. Physics:Quantum Stark effect
  11. Physics:Quantum Spectral lines and series
  12. Physics:Quantum Selection rules
  13. Physics:Quantum Fermi's golden rule
  14. Physics:Quantum beats
5. Wavefunctions and modes (9)↑
    A quantum wavefunction showing probability amplitude in space; the square of its magnitude gives the probability density.
  1. Physics:Quantum Wavefunction
  2. Physics:Quantum Superposition principle
  3. Physics:Quantum Eigenstates and eigenvalues
  4. Physics:Quantum Boundary conditions and quantization
  5. Physics:Quantum Standing waves and modes
  6. Physics:Quantum Normal modes and field quantization
  7. Physics:Number of independent spatial modes in a spherical volume
  8. Physics:Quantum Density of states
  9. Physics:Quantum carpet
6. Quantum dynamics and evolution (17)↑
  1. Physics:Quantum Time evolution
  2. Physics:Quantum Schrödinger equation
  3. Physics:Quantum Time-dependent Schrödinger equation
  4. Physics:Quantum Stationary states
  5. Physics:Quantum Perturbation theory
  6. Physics:Quantum Time-dependent perturbation theory
  7. Physics:Quantum Adiabatic theorem
  8. Physics:Quantum Scattering theory
  9. Physics:Quantum S-matrix
  10. Physics:Quantum tunnelling
  11. Physics:Quantum speed limit
  12. Physics:Quantum revival
  13. Physics:Quantum reflection
  14. Physics:Quantum oscillations
  15. Physics:Quantum jump
  16. Physics:Quantum boomerang effect
  17. Physics:Quantum chaos
7. Measurement and information (8)↑
  1. Physics:Quantum Measurement theory
  2. Physics:Quantum Measurement operators
  3. Physics:Quantum Projective measurement
  4. Physics:Quantum POVM
  5. Physics:Quantum Weak measurement
  6. Physics:Quantum Measurement collapse
  7. Physics:Quantum Zeno effect
  8. Physics:Quantum limit
8. Quantum information and computing (10)↑
  1. Physics:Quantum information theory
  2. Physics:Quantum Qubit
  3. Physics:Quantum Entanglement
  4. Physics:Quantum Gates and circuits
  5. Physics:Quantum Computing Algorithms in the NISQ Era
  6. Physics:Quantum Noisy Qubits
  7. Physics:Quantum random access code
  8. Physics:Quantum pseudo-telepathy
  9. Physics:Quantum network
  10. Physics:Quantum money
9. Quantum optics and experiments (5)↑
    Experimental quantum physics: qubits, dilution refrigerators, quantum communication, and laboratory systems.
  1. Physics:Quantum Nonlinear King plot anomaly in calcium isotope spectroscopy
  2. Physics:Quantum optics beam splitter experiments
  3. Physics:Quantum Ultra fast lasers
  4. Physics:Quantum Experimental quantum physics
  5. Physics:Quantum optics
    6. Template:Quantum optics operators
10. Open quantum systems (9)↑
  1. Physics:Quantum Open systems
  2. Physics:Quantum Master equation
  3. Physics:Quantum Lindblad equation
  4. Physics:Quantum Decoherence
  5. Physics:Quantum dissipation
  6. Physics:Quantum Markov semigroup
  7. Physics:Quantum Markovian dynamics
  8. Physics:Quantum Non-Markovian dynamics
  9. Physics:Quantum Trajectories
11. Quantum field theory (19)↑
    Structural dependency map of quantum field theory.
  1. Physics:Quantum field theory (QFT) basics
  2. Physics:Quantum field theory (QFT) core
  3. Physics:Quantum Fields and Particles
  4. Physics:Quantum Second quantization
  5. Physics:Quantum Harmonic Oscillator field modes
  6. Physics:Quantum Creation and annihilation operators
  7. Physics:Quantum vacuum fluctuations
  8. Physics:Quantum Propagators in quantum field theory
  9. Physics:Quantum Feynman diagrams
  10. Physics:Quantum Path integral formulation
  11. Physics:Quantum Renormalization in field theory
  12. Physics:Quantum Renormalization group
  13. Physics:Quantum Field Theory Gauge symmetry
  14. Physics:Quantum Non-Abelian gauge theory
  15. Physics:Quantum Electrodynamics (QED)
  16. Physics:Quantum chromodynamics (QCD)
  17. Physics:Quantum Electroweak theory
  18. Physics:Quantum Standard Model
  19. Physics:Quantum triviality
12. Statistical mechanics and kinetic theory (9)↑
  1. Physics:Quantum Statistical mechanics
  2. Physics:Quantum Partition function
  3. Physics:Quantum Distribution functions
  4. Physics:Quantum Liouville equation
  5. Physics:Quantum Kinetic theory
  6. Physics:Quantum Boltzmann equation
  7. Physics:Quantum BBGKY hierarchy
  8. Physics:Quantum Relaxation and thermalization
  9. Physics:Quantum Thermodynamics
13. Condensed matter and solid-state physics (13)↑
  1. Physics:Quantum Band structure
  2. Physics:Quantum Fermi surfaces
  3. Physics:Quantum Semiconductor physics
  4. Physics:Quantum Phonons
  5. Physics:Quantum Electron-phonon interaction
  6. Physics:Quantum Superconductivity
  7. Physics:Quantum Topological phases of matter
  8. Physics:Quantum well
  9. Physics:Quantum spin liquid
  10. Physics:Quantum spin Hall effect
  11. Physics:Quantum phase transition
  12. Physics:Quantum critical point
  13. Physics:Quantum dot
14. Plasma and fusion physics (8)↑
    Conceptual illustration of plasma physics in a fusion context, showing magnetically confined ionized gas in a tokamak and the collective behavior governed by electromagnetic fields and transport processes.
  1. Physics:Quantum Fusion reactions and Lawson criterion
  2. Physics:Quantum Plasma (fusion context)
  3. Physics:Quantum Magnetic confinement fusion
  4. Physics:Quantum Inertial confinement fusion
  5. Physics:Quantum Plasma instabilities and turbulence
  6. Physics:Quantum Tokamak core plasma
  7. Physics:Quantum Tokamak edge physics and recycling asymmetries
  8. Physics:Quantum Stellarator
15. Timeline (8)↑
  1. Physics:Quantum mechanics/Timeline
  2. Physics:Quantum mechanics/Timeline/Pre-quantum era
  3. Physics:Quantum mechanics/Timeline/Old quantum theory
  4. Physics:Quantum mechanics/Timeline/Modern quantum mechanics
  5. Physics:Quantum mechanics/Timeline/Quantum field theory era
  6. Physics:Quantum mechanics/Timeline/Quantum information era
  7. Physics:Quantum mechanics/Timeline/Quantum technology era
  8. Physics:Quantum mechanics/Timeline/Quiz
16. Advanced and frontier topics (9)↑
  1. Physics:Quantum topology
  2. Physics:Quantum battery
  3. Physics:Quantum Supersymmetry
  4. Physics:Quantum Black hole thermodynamics
  5. Physics:Quantum Holographic principle
  6. Physics:Quantum gravity
  7. Physics:Quantum De Sitter invariant special relativity
  8. Physics:Quantum Doubly special relativity
  9. Physics:Quantum arithmetic geometry

References

  1. ↑ Levine, Daniel S.; Head-Gordon, Martin (2020-09-29). "Clarifying the quantum mechanical origin of the covalent chemical bond". Nature Communications (Springer Science and Business Media LLC) 11 (1): 4893. doi:10.1038/s41467-020-18670-8. ISSN 2041-1723. PMID 32994392. Bibcode: 2020NatCo..11.4893L. 
  2. ↑ Pauling, L. (1931), "The nature of the chemical bond. Application of results obtained from the quantum mechanics and from a theory of paramagnetic susceptibility to the structure of molecules", Journal of the American Chemical Society 53 (4): 1367–1400, doi:10.1021/ja01355a027, Bibcode: 1931JAChS..53.1367P 
  3. ↑ Hund, F. (1928). "Zur Deutung der Molekelspektren. IV" (in de). Zeitschrift für Physik 51 (11–12): 759–795. doi:10.1007/BF01400239. ISSN 1434-6001. Bibcode: 1928ZPhy...51..759H. http://link.springer.com/10.1007/BF01400239. 
  4. ↑ Frenking, Gernot; Krapp, Andreas (2007-01-15). "Unicorns in the world of chemical bonding models" (in en). Journal of Computational Chemistry 28 (1): 15–24. doi:10.1002/jcc.20543. PMID 17109434. Bibcode: 2007JCoCh..28...15F. 
  5. ↑ Jensen, Frank (1999). Introduction to Computational Chemistry. John Wiley and Sons. ISBN 978-0-471-98425-2. 
  6. ↑ Pauling, Linus (1960). "The Concept of Resonance". The Nature of the Chemical Bond – An Introduction to Modern Structural Chemistry (3rd ed.). Cornell University Press. pp. 10–13. ISBN 978-0801403330. https://books.google.com/books?id=L-1K9HmKmUUC&pg=PA10. 
  7. ↑ Gillespie, R.J. (2004), "Teaching molecular geometry with the VSEPR model", Journal of Chemical Education 81 (3): 298–304, doi:10.1021/ed081p298, Bibcode: 2004JChEd..81..298G 
  8. ↑ Housecroft, Catherine E.; Sharpe, Alan G. (2005). Inorganic Chemistry (2nd ed.). Pearson Prentice-Hal. p. 100. ISBN 0130-39913-2. 
  9. ↑ Rioux, F. (2001). "The Covalent Bond in H2". The Chemical Educator 6 (5): 288–290. doi:10.1007/s00897010509a. 
  10. ↑ Streitwieser, Andrew; Heathcock, Clayton H.; Kosower, Edward M. (1992). Introduction to organic chemistry.. Heathcock, Clayton H., Kosower, Edward M. (4th ed.). New York: Macmillan. pp. 250. ISBN 978-0024181701. OCLC 24501305. https://archive.org/details/introductiontoor00stre_0/page/250. 
  11. ↑ Atkins, Peter; Loretta Jones (1997). Chemistry: Molecules, Matter and Change. New York: W.H. Freeman & Co.. pp. 294–295. ISBN 978-0-7167-3107-8. 
  12. ↑ Whittaker, Edmund T. (1989). A history of the theories of aether & electricity. 1: The classical theories (Repr ed.). New York: Dover Publ. ISBN 978-0-486-26126-3. 
  13. ↑ Pullman, Bernard (1998). The Atom in the History of Human Thought. Oxford, England: Oxford University Press. pp. 31–33. ISBN 978-0-19-515040-7. https://books.google.com/books?id=IQs5hur-BpgC&. Retrieved 25 October 2020. 
  14. ↑ "Law of definite proportions | chemistry" (in en). https://www.britannica.com/science/law-of-definite-proportions. 
  15. ↑ Hudson, John (1992) (in en). The History of Chemistry. Boston, MA: Springer US. doi:10.1007/978-1-4684-6441-2. ISBN 978-1-4684-6443-6. http://link.springer.com/10.1007/978-1-4684-6441-2. 
  16. ↑ Frankland, E. (1852). "On a New Series of Organic Bodies Containing Metals". Philosophical Transactions of the Royal Society of London 142: 417–444. doi:10.1098/rstl.1852.0020. 
  17. ↑ Abegg, R. (1904). "Die Valenz und das periodische System. Versuch einer Theorie der Molekularverbindungen" (in German). Zeitschrift für anorganische Chemie 39 (1): 330–380. doi:10.1002/zaac.19040390125. https://babel.hathitrust.org/cgi/pt?id=uc1.b3959087;view=1up;seq=344. 
  18. ↑ The Genesis of the Bohr Atom, John L. Heilbron and Thomas S. Kuhn, Historical Studies in the Physical Sciences, Vol. 1 (1969), pp. vi, 211-290 (81 pages), University of California Press.
  19. ↑ B. Bryson (2003). A Short History of Nearly Everything. Broadway Books. ISBN 0-7679-0817-1. 
  20. ↑ Original Proceedings of the 1911 Solvay Conference published 1912. THÉORIE DU RAYONNEMENT ET LES QUANTA. RAPPORTS ET DISCUSSIONS DELA Réunion tenue à Bruxelles, du 30 octobre au 3 novembre 1911, Sous les Auspices dk M. E. SOLVAY. Publiés par MM. P. LANGEVIN et M. de BROGLIE. Translated from the French, p. 127.
  21. ↑ Lewis, Gilbert N. (1916). "The Atom and the Molecule". Journal of the American Chemical Society 38 (4): 772. doi:10.1021/ja02261a002. Bibcode: 1916JAChS..38..762L. http://osulibrary.oregonstate.edu/specialcollections/coll/pauling/bond/papers/corr216.3-lewispub-19160400.html.  a copy
  22. ↑ Pais, Abraham (1986). Inward Bound: Of Matter and Forces in the Physical World. New York: Oxford University Press. pp. 228–230. ISBN 978-0-19-851971-3. https://archive.org/details/inwardboundofmat00pais_0/page/228. 
  23. ↑ Svidzinsky, Anatoly A.; Marlan O. Scully; Dudley R. Herschbach (2005). "Bohr's 1913 molecular model revisited". Proceedings of the National Academy of Sciences 102 (34): 11985–11988. doi:10.1073/pnas.0505778102. PMID 16103360. PMC 1186029. Bibcode: 2005PNAS..10211985S. http://www.pnas.org/content/102/34/11985.full.pdf. 
  24. ↑ Laidler, K. J. (1993). The World of Physical Chemistry. Oxford University Press. p. 346. ISBN 978-0-19-855919-1. https://archive.org/details/worldofphysicalc0000laid. 
  25. ↑ Heitler, W.; London, F. (1927). "Wechselwirkung neutraler Atome und homoopolare Bindung nach der Quantenmechanik". Zeitschrift für Physik 44 (6–7): 455–472. doi:10.1007/bf01397394. Bibcode: 1927ZPhy...44..455H.  English translation in Hettema, H. (2000). Quantum Chemistry: Classic Scientific Papers. World Scientific. pp. 140. ISBN 978-981-02-2771-5. https://books.google.com/books?id=qsidHRJmUoIC. Retrieved 2012-02-05. 
  26. ↑ James, H.H.; Coolidge, A S. (1933). "The Ground State of the Hydrogen Molecule". Journal of Chemical Physics 1 (12): 825–835. doi:10.1063/1.1749252. Bibcode: 1933JChPh...1..825J. 
  27. ↑ "Bond Energies". Chemistry Libre Texts. 2 October 2013. https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Chemical_Bonding/Fundamentals_of_Chemical_Bonding/Bond_Energies. 
  28. ↑ 28.0 28.1 28.2 28.3 28.4 Atkins, Peter; de Paula, Julio (2002). Physical Chemistry (7th ed.). W.H.Freeman. pp. 696–706. ISBN 0-7167-3539-3. 
  29. ↑ Ouellette, Robert J.; Rawn, J. David (2015). "Polar Covalent Bond". Science Direct. https://www.sciencedirect.com/topics/chemistry/polar-covalent-bond. "A polar covalent bond exists when atoms with different electronegativities share electrons in a covalent bond." 


Author: Harold Foppele





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