The Study of Some Stereochemical Problems by X-ray Analysis , The Structure of Ferroverdin, a Nitrosophenol iron (II) Chelate Produced by a Streptomycete Part II

摘要

Ferroverdin, a green iron-containing pigment, was isolated in 1955 from a streptomyces of unknown species. Chemical investiga¬tions led to the formula. X-ray crystallographic measurements show in two different crystal structures, that each iron atom is attached to three nitrosophenyl ligands and that the charge is balanced by sodium ions surrounded by six oxygen atoms from ferroverdin and solvent molecules. The crystal data for the two forms are:I Rhombohedral:space group, R3c;a = 16. 06 A, c = 88, 78 A;density 1. 42 g/cm3;M, asymmetric unit, 471;M, calculated for Fe/3 • Na/3 • C15H10NO4• CC14• CH3OH, 480, R = 16%. II Monoclinic:space group C2/c;a = 38.88 A;b = 13. 60 A, c = 18. 44 A;β =96° 41";density .1. 43 g/cm3;M, . asymmetric unit, 1, 042;M, calculated for Fe•Na• C45H30N3O12• 2(CH3)2CO, 1, 000. R = 11%. In this second part the refinement of the two structu¬res is discussed. The whole work is on three reports.