In chemistry, HOMO and LUMO are types of molecular orbitals. The acronyms stand for highest occupied molecular orbital and lowest unoccupied molecular orbital, respectively. HOMO and LUMO are sometimes collectively called the frontier orbitals, such as in the frontier molecular orbital theory.
Diagram of the HOMO and LUMO of a molecule. Each circle represents an electron in an orbital; when light of a high enough frequency is absorbed by an electron in the HOMO, it jumps to the LUMO.
3D model of the highest occupied molecular orbital in CO2
3D model of the lowest unoccupied molecular orbital in CO2
The energy difference between the HOMO and LUMO is the HOMO–LUMO gap. Its size can be used to predict the strength and stability of transition metalcomplexes, as well as the colors they produce in solution.[1] As a rule of thumb, the larger a compound's HOMO-LUMO gap, the more stable the compound.
In organometallic chemistry, the size of the LUMO lobe can help predict where addition to pi ligands will occur.
SOMO
A SOMO is a singly occupied molecular orbital such as half-filled HOMO of a radical.[3] This abbreviation may also be extended to semi occupied molecular orbital.
Subadjacent orbitals: NHOMO and SLUMO
If existent, the molecular orbitals at one energy level below the HOMO and one energy level above the LUMO are also found to play a role in frontier molecular orbital theory. They are named NHOMO for next-to-highest occupied molecular orbital and SLUMO for second lowest unoccupied molecular orbital.[4] These are also commonly referred to as HOMO−1 and LUMO+1 respectively.[5]
homo, lumo, homo, redirects, here, other, uses, homo, disambiguation, chemistry, types, molecular, orbitals, acronyms, stand, highest, occupied, molecular, orbital, lowest, unoccupied, molecular, orbital, respectively, sometimes, collectively, called, frontier. HOMO redirects here For other uses see Homo disambiguation In chemistry HOMO and LUMO are types of molecular orbitals The acronyms stand for highest occupied molecular orbital and lowest unoccupied molecular orbital respectively HOMO and LUMO are sometimes collectively called the frontier orbitals such as in the frontier molecular orbital theory Diagram of the HOMO and LUMO of a molecule Each circle represents an electron in an orbital when light of a high enough frequency is absorbed by an electron in the HOMO it jumps to the LUMO 3D model of the highest occupied molecular orbital in CO2 3D model of the lowest unoccupied molecular orbital in CO2 Contents 1 Gap 2 Semiconductors 3 Organometallic chemistry 4 SOMO 5 Subadjacent orbitals NHOMO and SLUMO 6 See also 7 References 8 Further reading 9 External linksGap EditThe energy difference between the HOMO and LUMO is the HOMO LUMO gap Its size can be used to predict the strength and stability of transition metal complexes as well as the colors they produce in solution 1 As a rule of thumb the larger a compound s HOMO LUMO gap the more stable the compound Semiconductors EditThe HOMO level is to organic semiconductors roughly what the maximum valence band is to inorganic semiconductors and quantum dots The same analogy can be made between the LUMO level and the conduction band minimum 2 Organometallic chemistry EditIn organometallic chemistry the size of the LUMO lobe can help predict where addition to pi ligands will occur SOMO EditA SOMO is a singly occupied molecular orbital such as half filled HOMO of a radical 3 This abbreviation may also be extended to semi occupied molecular orbital Subadjacent orbitals NHOMO and SLUMO EditIf existent the molecular orbitals at one energy level below the HOMO and one energy level above the LUMO are also found to play a role in frontier molecular orbital theory They are named NHOMO for next to highest occupied molecular orbital and SLUMO for second lowest unoccupied molecular orbital 4 These are also commonly referred to as HOMO 1 and LUMO 1 respectively 5 See also EditDiels Alder reaction Electron configuration Klopman Salem equation Koopmans theorem Ligand Woodward Hoffmann rulesReferences Edit Griffith J S and L E Orgel Ligand Field Theory Q Rev Chem Soc 1957 11 381 383 Bredas J L Mind the gap Mater Horiz 2014 1 17 19 IUPAC Compendium of Chemical Terminology 2nd ed the Gold Book 1997 Online corrected version 2006 SOMO doi 10 1351 goldbook S05765 IUPAC Compendium of Chemical Terminology 2nd ed the Gold Book 1997 Online corrected version 2006 subjacent orbital doi 10 1351 goldbook S06067 HOMO Molecular Orbital an overview ScienceDirect Topics Further reading EditFleming Ian 21 December 2009 Molecular Orbitals and Organic Chemical Reactions pp 1 360 ISBN 9780470746592 External links EditOrbiMol Molecular orbital database This quantum chemistry related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title HOMO and LUMO amp oldid 1131775650, wikipedia, wiki, book, books, library,
