Complexes of some tervalent metals with N-alkyl(benzyl)nitrozohydroxylamine derivatives

Abstract

Twenty two new complexes of some tervalent metals (aluminum, chromium, iron, and lanthanides) with nitrozohydroxylamine N-alkyl(benzyl) derivatives · nH 2 O, (m = 1-5) were synthesized and isolated in a crystalline state. The crystal and molecular structures of the iron(III) complex with N-(2-fluorobenzyl)-N-nitrozohydroxylamine were determined by X-ray diffraction. An octahedral coordination of the central ion and a bidentate chelating coordination of the organic ligand were established. The spectral criteria of coordination of nitrozohydroxylamine alkyl(benzyl) derivatives were determined, and the complexation processes in solutions were studied.The compounds containing N-nitrozohydroxylamine moieties are good chelating reagents able of forming stable metal complexes with metals of various types. They are widely used in chemistry as analytical reagents for the extraction of many metals [1][2][3][4][5][6][7][8][9][10][11][12][13][14] and their spectrophotometric analysis [15], and as precursors for the synthesis of nanoparticles of metal oxides [16][17][18][19][20].

Iron Coordination Properties of Gramibactin as Model for the New Class of Diazeniumdiolate Based Siderophores

“…For the [Fe(GBT)] − species, metal binding is clearly evidenced by a hypsochromic shift of the ligand absorption band upon coordination (from 246 to 240 nm), which is associated with a dramatic decrease in intensity. This is in agreement with what is reported in literature, namely for the iron(III) complex of the N ‐nitroso‐ N ‐methyl‐hydroxylamine ligand ( λ max : [L] − =246 nm, [FeL 3 ]=242 nm) [19, 30] . Moreover, upon coordination of the gramibactin ligand, an additional band for the [Fe(GBT)] − species is observed at 343 nm (Figure S2), which can be assigned to a ligand‐to‐metal charge transfer between the α‐hydroxocarboxylate hydroxy oxygen donor and iron(III) ion [24] .…”

“…The observed behavior can be rationalized based on the literature‐known protonation‐associated variation of the optical properties of the N ‐nitroso‐ N ‐hydroxylamine group. The protonated form is characterized by an intense, broad asymmetric UV absorption band at about 229 to 232 nm, which is assigned to a π–π* transition, whereas upon deprotonation this absorption band undergoes a bathochromic shift and appears in the range from 244 to 258 nm with a slight increase in the molar attenuation coefficient [19, 28–31] . Consequently, the present spectra support the deprotonation equilibria depicted in Scheme S2.…”

“…The protonatedf orm is characterized by an intense, broad asymmetric UV absorption band at about 229 to 232 nm, which is assigned to a p-p*t ransition, whereas upon deprotonation this absorption band undergoes ab athochromic shift and appearsi nt he range from 244 to 258 nm with as light increase in the molar attenuation coefficient. [19,[28][29][30][31] Consequently,t he present spectra support the deprotonatione quilibria depicted in Scheme S2.…”

“…[b] This work; I =0.1 mol dm −3 (KCl) and T= 298.15 K. [c] Ref. [31]; EtOH, T not indicated. [d] Ref.…”