Potentiometric and spectroscopic studies on aluminium(III) complexes of some catechol derivatives

Turkel N., Berker M., Ozer U.

CHEMICAL & PHARMACEUTICAL BULLETIN, cilt.52, sa.8, ss.929-934, 2004 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 52 Sayı: 8
  • Basım Tarihi: 2004
  • Doi Numarası: 10.1248/cpb.52.929
  • Dergi Adı: CHEMICAL & PHARMACEUTICAL BULLETIN
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.929-934
  • Bursa Uludağ Üniversitesi Adresli: Hayır

Özet

The interactions of aluminium(III) ion with the triprotic catechol derivatives (H3L), 2,3-dihydroxybenzoic acid (2,3-DHBA), 3,4-dihydroxyphenylacetic acid (3,4-DHPA), 3,4-dihydroxybenzoic acid (3,4-DHBA), and 3,4-dihydroxyhydrocinnamic acid (3,4-DHHCA) were investigated in aqueous solution at 25.0degreesC. The Calvin-Bjerrum titration method was adopted for the determination of formation constants of proton-ligand and aluminium(III)-ligand complexes. Potentiometric and spectroscopic results indicated that these catechol derivatives exhibit a true bidentate character. The chelation occurs via their catecholate sites, with the exception of 2,3-DHBA. In the case of 2,3-DHBA complexes, the dominant species are either the salicylate type (COO-, O-) or catecholate type (O-, O-) complex. The protonation constants of ligands and their formation constants of AI(III) complexes were also correlated. The order of decreasing stabilities of complexes is: 3,4-DHPA>3,4DHBA>3,4-DHHCA>2,3-DHBA.