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- Metal_aromaticity abstract "Metal aromaticity is simply the concept of aromaticity found in many organic compounds is extended to metals. The first experimental evidence for the existence of aromaticity in metals was found in aluminium cluster compounds of the type MAl4− where M stands for lithium, sodium or copper. These anions can be generated in a helium gas by laser vaporization of an aluminium / lithium carbonate composite or a copper or sodium / aluminium alloy, separated and selected by mass spectrometry and analyzed by photoelectron spectroscopy. The evidence for aromaticity in these compounds is based on several considerations. Computational chemistry shows that these aluminium clusters consist of a tetranuclear Al42− plane and a counterion at the apex of a square pyramid. The Al42− unit is perfectly planar and is not perturbed the presence of the counterion or even the presence of two counterions in the neutral compound M2Al4. In addition its HOMO is calculated to be a doubly occupied delocalized pi system making it obey Hückel's rule. Finally a match exists between the calculated values and the experimental photoelectron values for the energy required to remove the first 4 valence electrons. D-orbital aromaticity is found in trinuclear tungsten W3O9− and molybdenum Mo3O9− metal clusters generated by laser vaporization of the pure metals in the presence of oxygen in a helium stream. In these clusters the three metal centers are bridged by oxygen and each metal has two terminal oxygen atoms. The first signal in the photoelectron spectrum corresponds to the removal of the valence electron with the lowest energy in the anion to the neutral M3O9 compound. This energy turns out to be comparable to that of bulk tungsten trioxide and molybdenum trioxide. The photoelectric signal is also broad which suggests a large difference in conformation between the anion and the neutral species. Computational chemistry shows that the M3O9− anions and M3O92− dianions are ideal hexagons with identical metal-to-metal bond lengths. The molecules discussed thus far only exist diluted in the gas phase. A study exploring the properties of a compound formed in water from sodium molybdate (Na2MoO4.2H2O) and iminodiacetic acid also revealed evidence of aromaticity, but this compound has actually been isolated. X-ray crystallography showed that the sodium atoms are arranged in layers of hexagonal clusters akin to pentacenes. The sodium-to-sodium bond lengths are unusually short (327 pm versus 380 pm in elemental sodium) and, like benzene, the ring is planar. In this compound each sodium atom has a distorted octahedral molecular geometry with coordination to molybdenum atoms and water molecules. The experimental evidence is supported by computed NICS aromaticity values.".
- Metal_aromaticity wikiPageID "3220879".
- Metal_aromaticity wikiPageLength "4153".
- Metal_aromaticity wikiPageOutDegree "36".
- Metal_aromaticity wikiPageRevisionID "677449464".
- Metal_aromaticity wikiPageWikiLink Alloy.
- Metal_aromaticity wikiPageWikiLink Aromaticity.
- Metal_aromaticity wikiPageWikiLink Bond_length.
- Metal_aromaticity wikiPageWikiLink Category:Chemical_bonding.
- Metal_aromaticity wikiPageWikiLink Category:Cluster_chemistry.
- Metal_aromaticity wikiPageWikiLink Cluster_chemistry.
- Metal_aromaticity wikiPageWikiLink Computational_chemistry.
- Metal_aromaticity wikiPageWikiLink Counterion.
- Metal_aromaticity wikiPageWikiLink LUMO.
- Metal_aromaticity wikiPageWikiLink Helium.
- Metal_aromaticity wikiPageWikiLink Hxc3xbcckels_rule.
- Metal_aromaticity wikiPageWikiLink Iminodiacetic_acid.
- Metal_aromaticity wikiPageWikiLink Ion.
- Metal_aromaticity wikiPageWikiLink Laser_ablation.
- Metal_aromaticity wikiPageWikiLink Lithium.
- Metal_aromaticity wikiPageWikiLink Lithium_carbonate.
- Metal_aromaticity wikiPageWikiLink Mass_spectrometry.
- Metal_aromaticity wikiPageWikiLink Metal.
- Metal_aromaticity wikiPageWikiLink Molybdenum.
- Metal_aromaticity wikiPageWikiLink Molybdenum_trioxide.
- Metal_aromaticity wikiPageWikiLink NICS_aromaticity.
- Metal_aromaticity wikiPageWikiLink Octahedral_molecular_geometry.
- Metal_aromaticity wikiPageWikiLink Organic_compound.
- Metal_aromaticity wikiPageWikiLink Oxygen.
- Metal_aromaticity wikiPageWikiLink Pentacene.
- Metal_aromaticity wikiPageWikiLink Photoemission_spectroscopy.
- Metal_aromaticity wikiPageWikiLink Picometre.
- Metal_aromaticity wikiPageWikiLink Sodium.
- Metal_aromaticity wikiPageWikiLink Sodium_molybdate.
- Metal_aromaticity wikiPageWikiLink Square_pyramidal_molecular_geometry.
- Metal_aromaticity wikiPageWikiLink Tungsten.
- Metal_aromaticity wikiPageWikiLink Tungsten_trioxide.
- Metal_aromaticity wikiPageWikiLink X-ray_crystallography.
- Metal_aromaticity wikiPageWikiLinkText "Metal aromaticity".
- Metal_aromaticity wikiPageWikiLinkText "metal aromaticity".
- Metal_aromaticity wikiPageUsesTemplate Template:Chemical_bonds.
- Metal_aromaticity wikiPageUsesTemplate Template:Reflist.
- Metal_aromaticity wikiPageUsesTemplate Template:Use_dmy_dates.
- Metal_aromaticity subject Category:Chemical_bonding.
- Metal_aromaticity subject Category:Cluster_chemistry.
- Metal_aromaticity comment "Metal aromaticity is simply the concept of aromaticity found in many organic compounds is extended to metals. The first experimental evidence for the existence of aromaticity in metals was found in aluminium cluster compounds of the type MAl4− where M stands for lithium, sodium or copper.".
- Metal_aromaticity label "Metal aromaticity".
- Metal_aromaticity sameAs Q6822727.
- Metal_aromaticity sameAs Aromaticidad_metálica.
- Metal_aromaticity sameAs Aromaticidade_metálica.
- Metal_aromaticity sameAs m.08_8_8.
- Metal_aromaticity sameAs Aromatičnost_metala.
- Metal_aromaticity sameAs Aromatičnost_metala.
- Metal_aromaticity sameAs Q6822727.
- Metal_aromaticity wasDerivedFrom Metal_aromaticity?oldid=677449464.
- Metal_aromaticity isPrimaryTopicOf Metal_aromaticity.