Ligand‐Modification Effects on the Reactivity,Solubility, and Stability of Organometallic Tantalum Complexes in Water |
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Authors: | Dr. Ana Conde Dr. Rosa Fandos Dr. Carolina Hernández Prof. Dr. Antonio Otero Dr. Ana Rodríguez Dr. María José Ruiz |
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Affiliation: | 1. Departamento de Química Inorgánica, Orgánica y Bioquímica, Universidad de Castilla‐La Mancha, Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL), Facultad de Ciencias del Medio Ambiente, Avda. Carlos III, s/n, 45071 Toledo (Spain), Fax: (+34)?925268840;2. Departamento de Química Inorgánica, Orgánica y Bioquímica, Universidad de Castilla‐La Mancha, Facultad de Químicas, Campus de Ciudad Real, Avd. Camilo José Cela, 10, 13071 Ciudad Real (Spain), Fax: (+34)?926295318;3. Departamento de Química Inorgánica, Orgánica y Bioquímica, Universidad de Castilla‐La Mancha, ETS Ingenieros Industriales, Campus de Ciudad Real, Avd. Camilo José Cela, 3,13071 Ciudad Real (Spain) |
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Abstract: | Tantalum complexes [TaCp*Me{κ4‐C,N,O,O‐(OCH2)(OCHC(CH2NMe2)?CH)py}] ( 4 ) and [TaCp*Me{κ4‐C,N,O,O‐(OCH2)(OCHC(CH2NH2)?CH)py}] ( 5 ), which contain modified alkoxide pincer ligands, were synthesized from the reactions of [TaCp*Me{κ3‐N,O,O‐(OCH2)(OCH)py}] (Cp*=η5‐C5Me5) with HC?CCH2NMe2 and HC?CCH2NH2, respectively. The reactions of [TaCp*Me{κ4‐C,N,O,O‐(OCH2)(OCHC(Ph)?CH)py}] ( 2 ) and [TaCp*Me{κ4‐C,N,O,O‐(OCH2)(OCHC(SiMe3)?CH)py}] ( 3 ) with triflic acid (1:2 molar ratio) rendered the corresponding bis‐triflate derivatives [TaCp*(OTf)2{κ3‐N,O,O‐(OCH2)(OCHC(Ph)?CH2)py}] ( 6 ) and [TaCp*(OTf)2{κ3‐N,O,O‐(OCH2)(OCHC(SiMe3)?CH2)py}] ( 7 ), respectively. Complex 4 reacted with triflic acid in a 1:2 molar ratio to selectively yield the water‐soluble cationic complex [TaCp*(OTf){κ4‐C,N,O,O‐(OCH2)(OCHC(CH2NHMe2)?CH)py}]OTf ( 8 ). Compound 8 reacted with water to afford the hydrolyzed complex [TaCp*(OH)(H2O){κ3‐N,O,O‐(OCH2)(OCHC(CH2NHMe2)?CH2)py}](OTf)2 ( 9 ). Protonation of compound 8 with triflic acid gave the new tantalum compound [TaCp*(OTf){κ4‐C,N,O,O‐(OCH2)(HOCHC(CH2NHMe2)?CH)py}](OTf)2 ( 10 ), which afforded the corresponding protonolysis derivative [TaCp*(OTf)2{κ3‐N,O,O‐(OCH2)(HOCHC(CH2NHMe2)?CH2)py}](OTf) ( 11 ) in solution. Complex 8 reacted with CNtBu and potassium 2‐isocyanoacetate to give the corresponding iminoacyl derivatives 12 and 13 , respectively. The molecular structures of complexes 5 , 7 , and 10 were established by single‐crystal X‐ray diffraction studies. |
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Keywords: | alkoxides ligand effects organometallic complexes pincer ligands tantalum |
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