Органованадий химия

Химия органованадия - химия органометаллических соединений, содержащих углерод (C) с ванадия (V) химической связью . ^{[ 1 ]} Соединения органованадия обнаруживают лишь незначительное использование в качестве реагентов в органическом синтезе , но являются значимыми для химии полимеров в качестве катализаторов . ^{[ 2 ]}

Состояния окисления для ванадия составляют +2, +3, +4 и +5. Низкая валентность ванадия обычно стабилизируется карбонильными лигандами. Производные оксо встречаются относительно распространены, в отличие от органических комплексов соседних элементов.

Составные классы

Карбонилы

Ванадий карбонил может быть приготовлен путем восстановительного карбонилирования солей ванадия:

4 Na + VCl ₃ + 6 CO → Na[V(CO) ₆] + 3 NaCl

Соль может быть окислена до 17e бинарного карбонила V (CO) ₆ .

Циклопентадиенильные производные

(Cycloheptatrienyl)(cyclopentadienyl)vanadium is one of many organovanadium compounds that is paramagnetic.

Ванадоценовый дихлорид , первые комплексы органованадий, о которых сообщают, ^{[ 3 ]} готовится из тетрахлорида натрия циклопентадиенила и ванадия :

2 NaC₅H₅ + VCl₄ → VCp₂Cl₂ + 2NaCl

Reduction of this compound gives the parent vanadocene (Cp₂V):

VCp₂Cl₂ + LiAlH₄ → VCp₂

Cp₂V₂(CO)₅ featuring a pair of semi-bridging CO ligands.^[4]

Vanadocene is the lightest transition metal metallocene that is isolable at room temperature.^[5] Vanadocene reacts with high pressures of carbon monoxide to give CpV(CO)₄.^[6] Photolysis of the tetracarbonyl gives Cp₂V₂(CO)₅. Several analogous indenyl complexes are known.

Monocyclopentadienyl vanadium chlorides include CpVCl₃ and the diamagnetic CpVOCl₂.

Arene complexes

Vanadium forms a variety of arene complexes, e.g. with benzene:

VCl₄ + Al + 2 C₆H₆ → [V(η⁶-C₆H₆)₂]AlCl₄

[V(η⁶-C₆H₆)₂]AlCl₄ + H₂O → V(η⁶-C₆H₆)₂ + ...

Alkyl and aryl derivatives

A handful of alkyl and aryl complexes exist. The reactive species V(mesityl)₃ forms from VCl₃:^[7]

VCl₃(THF)₃ + 3 LiC₆H₂-2,4,6-Me₃ → V(C₆H₂-2,4,6-Me₃)₃(THF) + 3 LiCl

This species binds CO and, under appropriate conditions, N₂. V(mesityl)₃ adds a fourth mesityl group and the resulting "ate complex" can be oxidized to the vanadium(IV) derivative:

V(mes)₃(THF) + LiMes → Li[V(mes)₄]

Li[V(mes)₄] + air → V(mes)₄(THF)

The tetrakis(norbornyl) complex is also known.

Vanadium oxytrichloride is a starting material for organovanadium(IV) and organovanadium(V) compounds:

VOCl₃ + Li(mes) → Li[VO(mes)₃]

Li[VO(mes)₃] + chloranil → VO(mes)₃

VOCl₃ + ZnPh₂ → VOPhCl₂ + "ZnPh(Cl)"

Catalysts and reagents

Well-defined vanadium compounds do not appear as catalysts in any commercial process.^[8] However organovanadium species are clearly implicated as catalysts for the production of butadiene-based rubbers. These catalysts are generated in situ by treating soluble coordination complexes such as vanadium(III) acetylacetonate with organoaluminium activators.^[9]^[10]

References

^ Synthesis of Organometallic Compounds: A Practical Guide Sanshiro Komiya Ed. 1997
^ Kotohiro Nomura; Shu Zhang (2011). "Design of Vanadium Complex Catalysts for Precise Olefin Polymerization". Chem. Rev. 111 (3): 2342–2362. doi:10.1021/cr100207h. PMID 21033737.
^ Wilkinson, G.; Birmingham, J. G. (1954). "Bis-cyclopentadienyl Compounds of Ti, Zr, V, Nb and Ta". Journal of the American Chemical Society. 76 (17): 4281–4284. doi:10.1021/ja01646a008.
^ Fischer, Ernst Otto; Schneider, Robert J. J. (1970). "Über Aromatenkomplexe von Metallen, CXIV. Darstellung und Reaktionen von Dicyclopentadienyl-divanadin-pentacarbonyl, (C 5 H 5 ) 2 V 2 (CO) 5". Chemische Berichte. 103 (11): 3684–3695. doi:10.1002/cber.19701031133.
^ Robert Choukroun, Christian Lorber (2005). "Adventures in Vanadocene Chemistry". Eur. J. Inorg. Chem. 2005 (23): 4683–4692. doi:10.1002/ejic.200500371.
^ King, R.B.; Stone, F.G.A (1963). "Cyclopentadienyl Metal Carbonyls and Some Derivatives". Inorganic Syntheses. Vol. 7. pp. 99–115. doi:10.1002/9780470132388.ch31. ISBN 978-0-470-13238-8. {{cite book}}: |journal= ignored (help)
^ Vivanco, M.; Ruiz, J.; Floriani, C.; Chiesi-Villa, A.; Rizzoli, C. "Chemistry of the vanadium-carbon .sigma. bond. 1. Insertion of carbon monoxide, isocyanides, carbon dioxide, and heterocumulenes into the V-C bond of Tris(mesityl)vanadium(III)" Organometallics 1993 volume 12, 1794–1801. doi:10.1021/om00029a042
^ Toshikazu Hirao (1997). "Vanadium in Modern Organic Synthesis". Chemical Reviews. 97 (8): 2707–2724. doi:10.1021/cr960014g. PMID 11851478.
^ Kotohiro Nomura; Shu Zhang (2011). "Design of Vanadium Complex Catalysts for Precise Olefin Polymerization". Chem. Rev. 111 (3): 2342–2362. doi:10.1021/cr100207h. PMID 21033737.
^ Werner Obrecht; Jean-Pierre Lambert; Michael Happ; Christiane Oppenheimer-Stix; John Dunn; Ralf Krüger (2012). "Rubber, 4. Emulsion Rubber". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.o23_o01. ISBN 978-3527306732.

[1] Synthesis of Organometallic Compounds: A Practical Guide Sanshiro Komiya Ed. 1997

[2] Kotohiro Nomura; Shu Zhang (2011). "Design of Vanadium Complex Catalysts for Precise Olefin Polymerization". Chem. Rev. 111 (3): 2342–2362. doi:10.1021/cr100207h. PMID 21033737.

[wilkinson-3] Wilkinson, G.; Birmingham, J. G. (1954). "Bis-cyclopentadienyl Compounds of Ti, Zr, V, Nb and Ta". Journal of the American Chemical Society. 76 (17): 4281–4284. doi:10.1021/ja01646a008.

[4] Fischer, Ernst Otto; Schneider, Robert J. J. (1970). "Über Aromatenkomplexe von Metallen, CXIV. Darstellung und Reaktionen von Dicyclopentadienyl-divanadin-pentacarbonyl, (C 5 H 5 ) 2 V 2 (CO) 5". Chemische Berichte. 103 (11): 3684–3695. doi:10.1002/cber.19701031133.

[5] Robert Choukroun, Christian Lorber (2005). "Adventures in Vanadocene Chemistry". Eur. J. Inorg. Chem. 2005 (23): 4683–4692. doi:10.1002/ejic.200500371.

[RBK-6] King, R.B.; Stone, F.G.A (1963). "Cyclopentadienyl Metal Carbonyls and Some Derivatives". Inorganic Syntheses. Vol. 7. pp. 99–115. doi:10.1002/9780470132388.ch31. ISBN 978-0-470-13238-8. {{cite book}}: |journal= ignored (help)

[7] Vivanco, M.; Ruiz, J.; Floriani, C.; Chiesi-Villa, A.; Rizzoli, C. "Chemistry of the vanadium-carbon .sigma. bond. 1. Insertion of carbon monoxide, isocyanides, carbon dioxide, and heterocumulenes into the V-C bond of Tris(mesityl)vanadium(III)" Organometallics 1993 volume 12, 1794–1801. doi:10.1021/om00029a042

[8] Toshikazu Hirao (1997). "Vanadium in Modern Organic Synthesis". Chemical Reviews. 97 (8): 2707–2724. doi:10.1021/cr960014g. PMID 11851478.

[9] Kotohiro Nomura; Shu Zhang (2011). "Design of Vanadium Complex Catalysts for Precise Olefin Polymerization". Chem. Rev. 111 (3): 2342–2362. doi:10.1021/cr100207h. PMID 21033737.

[Ullmann-10] Werner Obrecht; Jean-Pierre Lambert; Michael Happ; Christiane Oppenheimer-Stix; John Dunn; Ralf Krüger (2012). "Rubber, 4. Emulsion Rubber". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.o23_o01. ISBN 978-3527306732.

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