Structures and Properties of Novel Mononuclear Iron(III) Complexes with Benzimidazole Containing Tripodal Tetradentate Ligands

✍ Scribed by Matthias Pascaly; Çetin Nazikkol; Florian Schweppe; Andreas Wiedemann; Kristin Zurlinden; Bernt Krebs

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: German
• Weight: 139 KB
• Volume: 626
• Category: Article
• ISSN: 0372-7874
• DOI: 10.1002/(sici)1521-3749(200001)626:1<50::aid-zaac50>3.0.co;2-y

✦ Synopsis

The iron(III) complexes of the tripodal benzimidazole-containing ligands tris(2-benzimidazolylmethyl)amine (ntb), bis(2-benzimidazolylmethyl)(2-hydroxyethyl)-amine (bbimae) and tris(5,6-dimethyl-2-benzimidazolylmethyl)amine (me 2 ntb) are structural and functional models for intradiol cleaving catechol dioxygenases. The complexes [Fe(ntb)Cl 2 ]Cl ´3 CH 3 OH (1; P 1, a = 9.830(2) A Ê , b = 12.542(3) A Ê , c = 13.139(3) A Ê , a = 82.88(3)°, b = 73.45(3)°, c = 85.53(3)°, V = 1539.2(6) A Ê 3 ; Z = 2) and [Fe(bbimae)Cl 2 ]Cl (2; P2 1 /n, a = 7.461(2) A Ê , b = 18.994(5) A Ê , c = 14.515(4) A Ê , b = 98.22(2)°, V = 2035.8( 9) A Ê 3 , Z = 4) have been characterized by X-ray crystallography and spectroscopic methods. In the octahedrally coordinated complexes two cis coordination sites ± essential for catechol binding ± are occupied by chloride ligands. The significant intradiol cleaving catechol dioxygenase activity of the model complexes was examined using 3,5-di-tert-butylcatechol as a substrate.