Bonding Capabilities of the Biochemical Buffer TRIS toward Copper(II) Ion. Structure and Magnetic Properties of Binuclear and Tetranuclear Systems

Abstract

SummaryFollowing X-ray crystal structure studies, the products of the reaction between Cu(I1) halides and tris(hydroxymethy1)methylamine (TRIS) can be formulated as [Cu(TRISH-,)(TRIS)],X, and [Cu(TRISH_,)X], (X = C1, Br). TRISH-, is the deprotonated ligand. Initial metal-ligand stoichiometric ratios of 1 : 2 and 1 : 1 are required to obtain the former and the latter species, respectively. Relevant crystal data for the dimeric compound with X = Br are: monoclinic, a = 11.394 (2) the arrangement is significantly puckered at this vector. One of these bridging O-atoms has p3 character as it serves as a weak apical donor for a Cu-atom of another binuclear unit. Thus a step-like geometry of the central core is obtained. Both compounds have constant magnetic moments at least down to the liquid N, temperature. In this respect, they differ from other complexes of Cu(I1) having comparable geometries, but temperature-dependent magnetic moments.Introduction. ~ The compound tris(hydroxymethy1)methylamine (TRIS)

Bis axially coordinated (phthalocyaninato)ruthenium(II) compounds

“…Examples for the polymers 1 are the (phthalocyaninato)iron and (tetrabenzoporphinato)iron compounds [PcFe(pyz)]", [PcFe(dib)]", [PcFe(bpy)]",2 [PcFe(tz)]"3 (tz = tetrazine), and [(TBP)Fe(dib)]^,4 for which we have recently published the preparation, characterization, and conductivities.…”

Ruthenium coordination preferences in imidazole‐containing systems revealed by electrospray ionization mass spectrometry and molecular modeling: Possible cues for the surprising stability of the Ru (III)/tris (hydroxymethyl)‐aminomethane/imidazole complexes

“…The reactivity of commonly used buffering compounds towards a wide range of biomolecules, particularly ones incorporating metal ions, is now widely recognized . Tris (tris (hydroxymethyl)‐aminomethane) in particular is known to form complexes with a variety of transition metals, and we recently observed facile oxidation and ligand exchange within the [Ru II (NH 3 ) 5 Cl] + complex upon its placement in Tris buffer under aerobic conditions . Earlier studies of Ru III complexation by tris (hydroxymethyl)‐aminomethane resulted in the complex structure assignment as [(RuTCl) 2 ]Cl 2 , where T denotes tris (hydroxymethyl)‐aminomethane .…”

“…The reactivity of commonly used buffering compounds towards a wide range of biomolecules, particularly ones incorporating metal ions, is now widely recognized. 24 Tris (tris (hydroxymethyl)-aminomethane) in particular is known to form complexes with a variety of transition metals, [25][26][27] Lastly, with only one exception, all Ru-containing complexes appear to contain the metal in its oxidized (ie, Ru III ) form (vide infra).…”

ChemInform Abstract: Interaction Between the Buffer Tris and the Eu(III) Ion: Luminescence and Potentiometric Investigation

“…Indeed, complexes with several transition metal ions, e.g. Mn(II), Fe(III), Co(III), Ni(II), Cu(II), have been isolated [2] [3], and the crystal structures of two Cu(I1) complexes have been established [3].Increasing interest for the role of metal ions in biochemical processes is stimulating numerous investigations. When spectroscopically silent metal ions such as Ca(I1) or Zn(I1) are involved, it is common practice to substitute them by metal ions having similar chemical properties and specific magnetic and/or spectroscopic properties.…”

“…Indeed, complexes with several transition metal ions, e.g. Mn(II), Fe(III), Co(III), Ni(II), Cu(II), have been isolated [2] [3], and the crystal structures of two Cu(I1) complexes have been established [3].…”