A new N,O-donor binucleating ligand and its first iron(III) complex as a model for the purple acid phosphatases

Synthesis, molecular structure and spectroscopic, electrochemical and magnetic properties of a new dinuclear iron complex containing µ-sulfate-di-µ-alkoxo bridges: evaluating the influence of the sulfate bridge on the physicochemical properties of the di-µ-alkoxo-diiron unit

“…The study of the properties of the complex [ 2 ] 2+ , 2, allowed us to confirm that the number and kind of bridging groups have a great influence on some physicochemical properties of these diiron compounds. In fact, the electrochemical and UV-Vis properties are the most sensitive to the changes in the number and kind of the bridging groups.…”

“…Furthermore, complex 3 helped us to confirm that the third bridging group (μ-SO 4 ) prevents the Fe-(μ-alkoxo) 2 -Fe unit from adopting a planar shape. Thus, only complex 2, which contains only two alkoxo bridging groups, presents a planar Fe-(μ-alkoxo) 2 (2) and 2.07(2) Å. 7 The packing arrangement of 3 is governed by both Van der Waals forces and hydrogen bonds.…”

“…[2][3][4][5][6][7][16][17][18][19] This is due to the high ε values observed in electronic spectra of PAPs, which are attributed to a tyrosine→Fe III charge transfer transition. Thus, such dinucleating ligands hold the two metal centers in close proximity and provide phenolate coordinating groups, allowing the study of the influence of such groups on the properties exhibited by the metal centers in the complexes as well as in the enzyme.…”

“…18 The elucidation of the molecular structure through X-ray diffraction of a number of different PAP enzymes has shown unequivocally that only one tyrosine residue is present in their active site, this being bound to the nonreducible iron ion. [12][13][14] As part of our continuing investigation into dinuclear iron complexes as models for the active site of PAPs, 2 21,22 Although the same ligand was used in the synthesis of complexes 1 and 2 (Table 1), the compounds exhibited distinct structural and physicochemical properties. In 1 the ligand H 2 BPClNOL showed a facial coordination mode and three bridging groups were formed (two alkoxo and one acetate), while in 2 the ligand showed a meridional coordination mode with only two alkoxo bridges.…”

Determination of catechin in green tea using a catechol oxidase biomimetic sensor

“…[1][2][3][4][5][6][7][8][9] The development of functional models of metalloenzymes for catalyst oxidation reactions is a subject of great interest. [10][11][12][13][14][15][16] Neves et al [17][18][19][20][21][22][23][24][25] have extensively synthesized and characterized model complexes to mimic the active site of the different enzymes (e.g., catechol oxidase, peroxidase, galactose oxidase, catalase, purple acid phosphatase). The majority of O 2 -reactive copper models have been based on the binuclear-Cu catechol oxidase.…”