Two different modes for copper(II) ion coordination to quinine-type ligands

Journal of the Brazilian Chemical Society

Pereira-Maia, Elene C.¹  Mangrich, Antonio S.¹  Rey, Nicolás A.¹  Universidade Federal de Minas Gerais, Belo Horizonte, Brazil¹  Centro de Desenvolvimento da Tecnologia Nuclear, Belo Horizonte, Brazil¹  Menezes, Maria Â. B. C.¹  Santos, Karina C. dos¹  Universidade Federal do Paraná, Curitiba, Brazil¹ 

关键词: quinine;    copper(II);    thermogravimetry;    IR spectroscopy;    EPR spectroscopy;   

DOI  :  10.1590/S0103-50532006000300010

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

Three new copper(II) complexes with the ligands quinuclidine [Cu(C7H13N)2(OH2)Cl]Cl·2H 2O (1), quinine [Cu(C20H23O2N2)(OH 2)2]ClO4 (2), and hydroquinidine [Cu(C20H27O2N2)(OH 2) Cl2]Cl·½H2O (3) have been isolated and characterized. The binding sites were assigned on the basis of vibrational spectroscopy, electron paramagnetic resonance, and thermal analysis results. The possibility of the involvement of the quinuclidinic nitrogen in the coordination was evidenced in complex 1, in which copper(II) is coordinated to two quinuclidine molecules. In the case of quinine-type ligands, if the starting material is deprotonated in both nitrogens, copper(II) coordination occurs through the quinuclidinic nitrogen, as in complex 2. In contrast, if the starting material is protonated in the quinuclidinic nitrogen the binding site is the quinolinic nitrogen, as in complex 3. Therefore, both nitrogens of quinine-type ligands constitute binding sites for copper(II) ions.

【 授权许可】

Unknown