Šestostruka veza

Šestostruka veza je tip kovalentne veze u kojoj učestvuje 12 vezujućih elektrona i čiji red veze je 6. Jedini poznati molekuli sa šestostrukim vezama su diatomski dimolibden (Mo₂) i divolfram (W₂), koji postoje u gasovitoj fazi. Postoji uverljiva evidencija da dva elementa periodnog sistema ne mogu da formiraju vezu većeg reda od 6.^[1]

Dimolibden i divolfram

Dimolibden (Mo₂) se može detektovati u gasovitoj fazi na niskim temperaturama (7 K) primenom tehnike laserskog isparavanja koristeći molibdensku ploču koristeći, na primer, blisko infracrvenu spektroskopiju ili UV spektroskopiju.^[2] Poput dihroma, singlet stanje se očekuje od dimolibdena.^[3] Viši red veze se odražava u kraćoj dužini veze od 194 pm.

Drugi molekuli

Mada diatomski Cr₂ i U₂ imaju formalne strukture sa vezama od dvanaest elektrona, njihovi efektivni redovi veze izvedeni iz kvantno hemijskih proračuna su manji od 5 (što odgovara petostrukim vezama).^[1]

Reference

^ ^а ^б Roos, Björn O.; Borin, Antonio C.; Gagliardi, Laura (2007). „Reaching the Maximum Multiplicity of the Covalent Chemical Bond” (PDF). Angewandte Chemie International Edition. 46 (9): 1469. PMID 17225237. doi:10.1002/anie.200603600.
^ D. Kraus, M. Lorenz & V. E. Bondybey (2001). „On the dimers of the VIB group: a new NIR electronic state of Mo₂”. PhysChemComm. 4 (10): 44—48. doi:10.1039/b104063b.
^ Merino, Gabriel; Donald, Kelling J.; D, Jason S.’Acchioli & Hoffmann, Roald (2007). „The Many Ways To Have a Quintuple Bond”. J. Am. Chem. Soc. 129 (49): 15295—15302. PMID 18004851. doi:10.1021/ja075454b.

Literatura

Bursten, Bruce E.; F. Albert Cotton; Hall, Michael B. (1980). „Dimolybdenum: nature of the sextuple bond”. Journal of the American Chemical Society. 102 (20): 6348. doi:10.1021/ja00540a034.
Borin, A; Gobbo, João Paulo; Roos, Björn O. (2008). „A theoretical study of the binding and electronic spectrum of the Mo2 molecule”. Chemical Physics. 343 (2–3): 210. Bibcode:2008CP....343..210B. doi:10.1016/j.chemphys.2007.05.028.
Goodgame, Marvin M. & Goddard, William A. III (1981). „The "sextuple" bond of chromium dimer”. The Journal of Physical Chemistry. 85 (3): 215. doi:10.1021/j150603a001.
Chisholm, Mh (2007). „Metal to metal multiple bonds in ordered assemblies” (Free full text). Proceedings of the National Academy of Sciences of the United States of America. 104 (8): 2563—70. Bibcode:2007PNAS..104.2563C. PMC 1815223 . PMID 17299047. doi:10.1073/pnas.0610364104.
Norman, Joe G.; Ryan, P. Barry (1980). „Metal-metal bond energies in diatomic molybdenum, octachloromolybdate (Mo2Cl84-), and molybdenum formate (Mo2(O2CH)4)”. Journal of Computational Chemistry. 1 (1): 59—63. doi:10.1002/jcc.540010107.
Atha, P. M.; Hillier, I. H.; Guest, M. F. (1980). „Electron correlation and the nature of the sextuple bond in the dimolybdenum molecule”. Chemical Physics Letters. 75 (1): 84—86. Bibcode:1980CPL....75...84A. doi:10.1016/0009-2614(80)80469-6.
Wood, Carol; Doran, Mark; Hillier, Ian H.; Guest, Martyn F. (1980). „Theoretical study of the electronic structure of the transition metal dimers, discandium, dichromium, dimolybdenum, and dinickel”. Faraday Symp. R. Soc. Chem. 14 (Diatomic Met. Met. Clusters): 159—169. doi:10.1039/fs9801400159.

[Roos-1] а ^б Roos, Björn O.; Borin, Antonio C.; Gagliardi, Laura (2007). „Reaching the Maximum Multiplicity of the Covalent Chemical Bond” (PDF). Angewandte Chemie International Edition. 46 (9): 1469. PMID 17225237. doi:10.1002/anie.200603600.

[2] D. Kraus, M. Lorenz & V. E. Bondybey (2001). „On the dimers of the VIB group: a new NIR electronic state of Mo₂”. PhysChemComm. 4 (10): 44—48. doi:10.1039/b104063b.

[3] Merino, Gabriel; Donald, Kelling J.; D, Jason S.’Acchioli & Hoffmann, Roald (2007). „The Many Ways To Have a Quintuple Bond”. J. Am. Chem. Soc. 129 (49): 15295—15302. PMID 18004851. doi:10.1021/ja075454b.

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