Journal of Chemical Sciences | |
Chemistry of azopyrimidines. Part IV. Aromatic hydroxylation in palladium(II)-arylazopyrimidines | |
Ramkrishna Roy1  Chittaranjan Sinha11  Prasanta Kumar Santra1  | |
[1] Department of Chemistry, University of Burdwan, Burdwan 713 104, India$$ | |
关键词: Arylazopyrimidines; palladium(II); aromatic hydroxylation; oxygen insertion; spectral characterization; electrochemistry.; | |
DOI : | |
来源: Indian Academy of Sciences | |
【 摘 要 】
2-(Arylazo)pyrimidines (aapm) are N,N -chelating ligands and synthesise orange-red complexes of composition [Pd(aapm)Cl2], 1, with Pd(MeCN)2Cl2 in MeCN. The complex has cis-PdCl2 configuration [(Pd−Cl): 340, 360 cm-1]. The treatment of Tollen’s reagent (`AgOH’) leads to chelatative hydroxylation in the pendant aryl ring, affording a green phenolato complex, Pd(aapmO)Cl, 5 (aapmO is deprotonated 2-((8-hydroxo)arylazo)pyrimidine). The reaction is also carried out by controlled addition of dilute sodium hydroxide in air or by the addition of PhIO/ð‘š-chloroperbenzoic acid to a MeCN suspension of the complex. A single Pd-Cl stretch at 360 cm-1 supports the composition of phenolato complex. Unlike Pd(aapm)Cl2 the hydroxylated product, Pd(aapmO)Cl, has a structured intense absorption in the visible region near 670 nm. The Pd-Cl bond in Pd(aapmO)Cl is highly sensitive to nucleophilic substitution and slowly hydrolyses in aqueous medium.
【 授权许可】
Unknown
【 预 览 】
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RO201912040507372ZK.pdf | 108KB | download |