Coordination compounds of pteridine, alloxazine and flavin ligands: structures and properties

The pteridine and (iso)alloxazine pi systems are the underlying heterocycli c structures of coenzymatic constituents (pterins, lumazines, flavins) of o xidoreductase enzymes. These molecules are potential ligands for metal cent ers which, in the absence of additional coordination sites, bind predominan tly through O(4) and N(5) to form five-membered, redox-active alpha-iminoke to chelate rings. Recent results from spectroscopic and electrochemical stu dies and structural data are summarized in this article. (C) 1999 Elsevier Science S.A. All rights reserved.