The cobalt(II)-substituted proinsulin and insulin hexamers have been studied in solution via electronic absorption spectroscopy. Hexameric proinsulin is shown to undergo the phenol-induced T6 to R6 conformational transition in a manner analogous to that previously established for insulin. In the absence of coordinating anions, the coordination spheres of the Co(II) ions in the proinsulin and in...

Anticancer drugs A series of monoand dinuclear (η-arene) ruthenium(II) complexes were prepared by reaction of thiosemicarbazone ligands derived from benzaldehyde and ruthenium(II) precursors of the general formula [Ru(η-arene)(μ-Cl)Cl]2, where arene=p-PrC6H4Me or C6H5C3H6COOH. These complexes were characterized by NMR and IR spectroscopy, ESI-mass spectrometry and elemental analysis. The molecu...

A new molecular precursor strategy has been used to prepare a series of single-site catalysts that possess isolated iron centers supported on mesoporous SBA-15 silica. The iron centers were introduced via grafting reactions of the tris(tert-butoxy)siloxy iron(III) complex Fe[OSi(O(t)Bu)(3)](3)(THF) with SBA-15 in dry hexane. This complex reacts cleanly with the hydroxyl groups of SBA-15 to elim...

S=2 oxoiron(IV) species act as reactive intermediates in the catalytic cycle of nonheme iron oxygenases. The few available synthetic FeIV=O complexes known to date are often limited trigonal bipyramidal and very rarely octahedral geometries. Herein we describe generation characterization an pseudotetrahedral complex 2 supported by sterically demanding 1,4,7-tri-tert-butyl-1,4,7-triazacyclononan...

The high-spin pseudotetrahedral complex [Co(C3S5)2](2-) exhibits slow magnetic relaxation in the absence of an applied dc magnetic field, one of a small number of mononuclear complexes to display this property. Fits to low-temperature magnetization data indicate that this single-molecule magnet possesses a very large and negative axial zero-field splitting and small rhombicity. The presence of ...

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In this article, we submit the description of synthesis and identification of manganese(II) complexes with pyrogenic nanosilica-immobilized (d av = 10 nm; S sp = 290 m(2)/g) hydroxyaldimine ligands [Formula: see text]: salicilaldiminopropyl (L1); 5-bromosalicilaldiminopropyl (L2); 2-hydroxynaphtaldiminopropyl (L3); 2-hydroxy-3-methoxybenzaldiminopropyl (L4); 2-hydroxy-3,5-dichloroacetophenonimi...

in this paper, two double helical dinuclear copper(ii) complexes of bis-n,o-bidentate schiff base ligands bis(3-methoxy-n-salicylidene-4,4'-diaminodiphenyl)sulfone (l1) and bis(5-bromo-n-salicylidene-4,4'-diaminodiphenyl)sulfone (l2) were prepared and characterized by elemental analyses (chn), as well as thermal analysis. elemental analyses (chn) suggested that the reaction between ligands and ...

This paper presents aspects of the coordination chemistry of mono- and divalent manganese complexes supported by the anionic tris(phosphino)borate ligand, [PhBP(i)(Pr)3] (where [PhBP(i)(Pr)3] = [PhB(CH(2)P(i)Pr2)3]-). The Mn(II) halide complexes, [PhBP(i)(Pr)3]MnCl (1) and [PhBP(i)(Pr)3]MnI (2), have been characterized by X-ray diffraction, SQUID magnetometry, and EPR spectroscopy. Compound 2 s...