Waterstofoksalaat

**Eienskappe**
Algemeen
Naam	Waterstofoksalaat
IUSTC-naam	Waterstofetaandiöaat
Ander name	2-hidroksi-2-oksoasetaat
Struktuurformule van Waterstofoksalaat
Chemiese formule	HC₂O−4
Molêre massa	89,027 g•mol^-1
CAS-nommer	920-52-5
Fasegedrag
Smeltpunt
Kookpunt
Digtheid
Oplosbaarheid
Suur-basis eienskappe
pKa
Veiligheid
Flitspunt
Tensy anders vermeld is alle data vir standaardtemperatuur en -druk toestande.

Portaal Chemie

Waterstofoksalaat is 'n anioon met chemiese formule HC₂O−4 (of HO₂C-CO−2) wat van oksaalsuur deur die verlies van 'n enkele proton of, alternatiewelik, van die oksalaatanioon (C₂O2−4) deur byvoeging van 'n proton afgelei is.

Verskeie waterstofoksalate is goed bestudeer, insluitend natriumwaterstofoksalaat (NaHC₂O₄),^[1]^[2] kaliumwaterstofoksalaat (KHC₂O₄),^[3] ammoniumwaterstofoksalaat (NH₃HC₂O₄), rubidiumwaterstofoksalaat (RbHC₂O₄)^[4] en dimetielammoniumwaterstofoksalaat ((CH₃)₂NH₂HC₂O₄).^[5]

Veral in ouer literatuur word daar ook na waterstofoksalate as bioksalate, suuroksalate of monobasiese oksalate verwys.

Waterstofoksalaat word as amfoteries geklassifiseer dws. dit kan óf 'n as suur óf as 'n basis in 'n chemiese reaksie reageer.

Struktuur

Die meeste hidrogenoksalaatsoute is gehidreer. Byvoorbeeld, kaliumwaterstofoksalaat kristalliseer as 2KHC₂O₄·H₂O. Hierdie materiale vertoon uitgebreide strukture as gevolg van waterstofbinding en anioon-katioon interaksies. Die hidrate dehidreer by verhitting:^[3]

2KHC₂O₄·H₂O → 2KHC₂O₄ + H₂O

Waterstofoksalaat is gebruik om die intramolekulêre oordrag van die waterstofioon te bestudeer. Aangesien die reaksie oënskynlik bloot die beweging van die waterstofioon (proton) behels, is aanvaar dat die laagste energie-oriëntasie van die waterstofoksalaatmolekule wat die reaksie sou vergemaklik die cis-oriëntasie sou wees. 'n Meer ingewikkelde situasie is egter teenwoordig wat koppeling tussen die protonbeweging en die interne vryheidsgrade, beweging van die suurstofatome en kwantumtonneling van die waterstofioon behels.^[6]

Kyk ook

Waterstofkarbonaat

Verwysings

↑ Tellgren, Roland; Olovsson, Ivar (1971). "The crystal structures of normal and deuterated sodium hydrogen oxalate monohydrate NaHC₂O₄·H₂O and NaDC₂O₄·D₂O. Hydrogen bond studies XXXVI". The Journal of Chemical Physics. 54: 127–134. Bibcode:1971JChPh..54..127T. doi:10.1063/1.1674582.
↑ Delaplane, R. G.; Tellgren, R.; Olovsson, I. (1984). "Neutron diffraction study of sodium hydrogen oxalate monohydrate, NaHC₂O₄·H₂O, at 120 K". Acta Crystallographica. C40 (11): 1800–1803. doi:10.1107/S0108270184009616.
↑ ^3,0 ^3,1 "The decomposition of potassium hydrogen oxalate hemihydrate". Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character. The Royal Society. 125 (799): 635–646. 1929. doi:10.1098/rspa.1929.0192. ISSN 0950-1207.
↑ Hamadène, M.; Kherfi, H.; Guehria-Laidoudi, A. (2006). "The polymeric anhydrous rubidium hydrogen oxalate". Acta Crystallographica. A62: s280. doi:10.1107/S0108767306094414.
↑ Diallo, Waly; Gueye, Ndongo; Crochet, Aurélien; Plasseraud, Laurent; Cattey, Hélène (11 April 2015). "Crystal structure of dimethylammonium hydrogen oxalate hemi(oxalic acid)". Acta Crystallographica Section E Crystallographic Communications. International Union of Crystallography (IUCr). 71 (5): 473–475. doi:10.1107/s2056989015005964. ISSN 2056-9890.
↑ Bosch, Enric; Moreno, Miquel; Lluch, José María (1 Januarie 1992). "The role of coupling in intramolecular proton transfer reactions. The hydrogen oxalate anion as an example". Canadian Journal of Chemistry. Canadian Science Publishing. 70 (1): 100–106. doi:10.1139/v92-017. ISSN 0008-4042.

[Roland-1] Tellgren, Roland; Olovsson, Ivar (1971). "The crystal structures of normal and deuterated sodium hydrogen oxalate monohydrate NaHC₂O₄·H₂O and NaDC₂O₄·D₂O. Hydrogen bond studies XXXVI". The Journal of Chemical Physics. 54: 127–134. Bibcode:1971JChPh..54..127T. doi:10.1063/1.1674582.

[Delaplane-2] Delaplane, R. G.; Tellgren, R.; Olovsson, I. (1984). "Neutron diffraction study of sodium hydrogen oxalate monohydrate, NaHC₂O₄·H₂O, at 120 K". Acta Crystallographica. C40 (11): 1800–1803. doi:10.1107/S0108270184009616.

[RoyalSoc-3] 3,0 ^3,1 "The decomposition of potassium hydrogen oxalate hemihydrate". Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character. The Royal Society. 125 (799): 635–646. 1929. doi:10.1098/rspa.1929.0192. ISSN 0950-1207.

[Hamadene-4] Hamadène, M.; Kherfi, H.; Guehria-Laidoudi, A. (2006). "The polymeric anhydrous rubidium hydrogen oxalate". Acta Crystallographica. A62: s280. doi:10.1107/S0108767306094414.

[Diallo-5] Diallo, Waly; Gueye, Ndongo; Crochet, Aurélien; Plasseraud, Laurent; Cattey, Hélène (11 April 2015). "Crystal structure of dimethylammonium hydrogen oxalate hemi(oxalic acid)". Acta Crystallographica Section E Crystallographic Communications. International Union of Crystallography (IUCr). 71 (5): 473–475. doi:10.1107/s2056989015005964. ISSN 2056-9890.

[Bosch-6] Bosch, Enric; Moreno, Miquel; Lluch, José María (1 Januarie 1992). "The role of coupling in intramolecular proton transfer reactions. The hydrogen oxalate anion as an example". Canadian Journal of Chemistry. Canadian Science Publishing. 70 (1): 100–106. doi:10.1139/v92-017. ISSN 0008-4042.

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