Copper(II) complexes of hydroquinone-containing Schiff bases. Towards a structural model for copper amine oxidases

Redox‐Active p‐Quinone‐Based Bis(pyrazol‐1‐yl)methane Ligands: Synthesis and Coordination Behaviour

“…[28] Because p-quinones have not only been recognised as ubiquitous electrontransfer agents in biology, but also as important redox cofactors ("quinoenzymes"), [29] replacement of the 2-hydroxyphenyl substituent in (2-hydroxyphenyl)bis(pyrazol-1-yl)methanes by a p-hydroquinone moiety as in C could provide interesting perspectives for modelling the active sites of phydroquinone-containing metalloenzymes, such as copperdependent amine oxidases (cofactor: topaquinone = 2,4,5-trihydroxyphenylalaninequinone). [30][31][32] Further evidence for the potential of C-type ligands in homogeneous catalysis stems from Bäckvall et al who employed p-hydroquinone as a co-catalyst in Pd II -catalysed aerobic oxidations of monoolefins and conjugated dienes. [33] Moreover, Pd II complexes of simple bidentate nitrogen ligands are active catalysts for styrene/CO copolymerisation provided that p-benzoquinone is added to the methanolic reaction mixture.…”

Synthesis, characterization, and formation constant of hexacoordinate iron(III) complexes

“…Thermochromism and photochromism of the ligands [8], preparation, properties, and structural aspects of some Mn [9][10][11], Fe [12], Co [13][14][15], Cu [14][15][16][17], Ni [14,15], V [18], and Ga [12] complexes with these Schiff bases have been carried out. Comparatively little work is available on complexation and formation constants of Fe(III) compounds.…”

Biomimetic Applications of Metal Systems Supported by Scorpionates

“…5c) (Foster et al, 2000) was synthesized and electrochemically characterized in order to model Cu/TPQ interactions in CuAOases. In the structure of [HB(pz Ph,Ph ) 3 ]Cu(L), copper adopts a distorted square-pyramidal geometry, with a longer Cu-N interaction in axial position, as was previously found for similar complexes (Li et al, 2000) and in TPQ-on CuAOases (Nakamura et al, 1992;Speier et al, 1994). Model complexes have been reported to reproduce the peculiar structure and spectroscopic features of blue copper proteins Kitajima et al, 1992;Holland & Tolman, 1999;, or the function of these biological electron carriers (Rorabacher, 2004).…”