Niobium(V) ethoxide is an metalorganic compound with formula Nb2(OC2H5)10. It is a colorless liquid that dissolves in some organic solvents but hydrolyzes readily.[2] It is mainly used for the sol-gel processing of materials containing niobium oxides.[4]
Metal alkoxides rarely adopt monomeric structures, and niobium(V) ethoxide is no exception. Early studies established that niobium alkoxides aggregate in solution as dimers.[5] Subsequent crystallographic analysis established that the methoxide and isopropoxides of niobium adopt bioctahedral structures.[6] From a geometric perspective, the ten ethoxide ligand oxygen atoms of the Nb2(OEt)10 molecule in solution define a pair of octahedra sharing a common edge with the two niobium atoms located at their centres. From a bonding perspective, each niobium centre is surrounded octahedrally by four monodentate and two bridging ethoxide ligands. The oxygen atoms of the bridging ethoxides are each bonded to both niobium centres, and these two ligands are cis to one another within the coordination sphere. The formula [(EtO)4Nb(μ-OEt)]2 more comprehensively represents this dimeric structure, though the simplified formula is commonly used for most purposes.
The most important reaction of niobium alkoxides is their hydrolysis to produce films and gels of niobium oxides.[4] Although these reactions are complex, they can be described by this simplified equation:
Nb2(OC2H5)10 + 5 H2O → Nb2O5 + 10 HOEt
The thermal decomposition of Nb(OC2H5)5 begins above 325 – 350 °C. This can be observed with QMS as an increasing amount of ethanol and ethane released. Diethyl ether, C2H5OC2H5, and niobium(V) oxide are the decomposition products released following an atomic layer deposition or chemical vapor deposition process. The decomposition reaction can be summarised as:[7]
Nb2(OC2H5)10 → Nb2O5 + 5 O(C2H5)2
ReferencesEdit
^"ChemSpider CSID:13600". ChemSpider. Retrieved 17 November 2012.
^ abW. M. Haynes. CRC Handbook of Chemistry and Physics, 93rd Edition. Physical Constants of Inorganic Compounds.
^ ab"Niobium(5+) ethanolate". webbook.nist.gov. Retrieved November 15, 2012.
^ abU. Schubert "Sol–Gel Processing of Metal Compounds" Comprehensive Coordination Chemistry II 2003, Pages 629–656 Volume 7. doi:10.1016/B0-08-043748-6/06213-7
^Bradley, D. C.; Holloway, C. E. (1968). "Nuclear Magnetic Resonance Studies on Niobium and Tantalum Penta-alkoxides". J. Chem. Soc. A: 219–223. doi:10.1039/J19680000219. S2CID 98638647.
^Mehrotra, Ram C.; Singh, Anirudh (1997). "Recent Trends in Metal Alkoxide Chemistry". In Karlin, Kenneth D. (ed.). Progress in Inorganic Chemistry. Vol. 46. John Wiley & Sons. pp. 239–454. doi:10.1002/9780470166475.ch4. ISBN9780470167045.
^Rahtu, Antti (2002). Atomic Layer Deposition of High Permittivity Oxides: Film Growth and In Situ Studies (Thesis). University of Helsinki. hdl:10138/21065. ISBN952-10-0646-3.
October 22, 2023
niobium, ethoxide, metalorganic, compound, with, formula, oc2h5, colorless, liquid, that, dissolves, some, organic, solvents, hydrolyzes, readily, mainly, used, processing, materials, containing, niobium, oxides, niobium, ethoxide, skeletal, structure, niobium. Niobium V ethoxide is an metalorganic compound with formula Nb2 OC2H5 10 It is a colorless liquid that dissolves in some organic solvents but hydrolyzes readily 2 It is mainly used for the sol gel processing of materials containing niobium oxides 4 Niobium V Ethoxide Skeletal structure of niobium V ethoxideIdentifiersCAS Number 3236 82 63D model JSmol Interactive imageChemSpider 21241198ECHA InfoCard 100 019 814EC Number 221 795 2PubChem CID 520571CompTox Dashboard EPA DTXSID5062924InChI Key PNCDAXYMWHXGON UHFFFAOYSA NInChI 1S 5C2H5O Nb c5 1 2 3 h5 2H2 1H3 q5 1 5 1 SMILES CCO Nb OCC OCC OCC OCCPropertiesChemical formula C10H25NbO5Molar mass 318 209 g mol 1Appearance Colourless liquidDensity 1 258 g cm 3Melting point 5 C 41 F 278 K Boiling point 203 C 397 F 476 K Solubility in water N A reacts with water 2 ThermochemistryStd enthalpy offormation DfH 298 1583 9 2 7 kJ mol 1 3 Std enthalpy ofcombustion DcH 298 6872 6 1 7 kJ mol 1 3 HazardsGHS labelling PictogramsSignal word DangerHazard statements H226 H314Precautionary statements P210 P233 P240 P241 P242 P243 P260 P264 P280 P301 P330 P331 P303 P361 P353 P304 P340 P305 P351 P338 P310 P321 P363 P370 P378 P403 P235 P405 P501NFPA 704 fire diamond 111CORFlash point 36 C 97 F 309 KExcept where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa Infobox referencesStructure EditMetal alkoxides rarely adopt monomeric structures and niobium V ethoxide is no exception Early studies established that niobium alkoxides aggregate in solution as dimers 5 Subsequent crystallographic analysis established that the methoxide and isopropoxides of niobium adopt bioctahedral structures 6 From a geometric perspective the ten ethoxide ligand oxygen atoms of the Nb2 OEt 10 molecule in solution define a pair of octahedra sharing a common edge with the two niobium atoms located at their centres From a bonding perspective each niobium centre is surrounded octahedrally by four monodentate and two bridging ethoxide ligands The oxygen atoms of the bridging ethoxides are each bonded to both niobium centres and these two ligands are cis to one another within the coordination sphere The formula EtO 4Nb m OEt 2 more comprehensively represents this dimeric structure though the simplified formula is commonly used for most purposes Preparation and reactions EditThis compound is prepared by salt metathesis from niobium pentachloride Et C2H5 10 NaOEt Nb2Cl10 Nb2 OC2H5 10 10 NaClThe most important reaction of niobium alkoxides is their hydrolysis to produce films and gels of niobium oxides 4 Although these reactions are complex they can be described by this simplified equation Nb2 OC2H5 10 5 H2O Nb2O5 10 HOEtThe thermal decomposition of Nb OC2H5 5 begins above 325 350 C This can be observed with QMS as an increasing amount of ethanol and ethane released Diethyl ether C2H5OC2H5 and niobium V oxide are the decomposition products released following an atomic layer deposition or chemical vapor deposition process The decomposition reaction can be summarised as 7 Nb2 OC2H5 10 Nb2O5 5 O C2H5 2References Edit ChemSpider CSID 13600 ChemSpider Retrieved 17 November 2012 a b W M Haynes CRC Handbook of Chemistry and Physics 93rd Edition Physical Constants of Inorganic Compounds a b Niobium 5 ethanolate webbook nist gov Retrieved November 15 2012 a b U Schubert Sol Gel Processing of Metal Compounds Comprehensive Coordination Chemistry II 2003 Pages 629 656 Volume 7 doi 10 1016 B0 08 043748 6 06213 7 Bradley D C Holloway C E 1968 Nuclear Magnetic Resonance Studies on Niobium and Tantalum Penta alkoxides J Chem Soc A 219 223 doi 10 1039 J19680000219 S2CID 98638647 Mehrotra Ram C Singh Anirudh 1997 Recent Trends in Metal Alkoxide Chemistry In Karlin Kenneth D ed Progress in Inorganic Chemistry Vol 46 John Wiley amp Sons pp 239 454 doi 10 1002 9780470166475 ch4 ISBN 9780470167045 Rahtu Antti 2002 Atomic Layer Deposition of High Permittivity Oxides Film Growth and In Situ Studies Thesis University of Helsinki hdl 10138 21065 ISBN 952 10 0646 3 Retrieved from https en wikipedia org w index php title Niobium V ethoxide amp oldid 1094032381, wikipedia, wiki, book, books, library,
