两种新型铬配合物TBA[Cr(SA)2(en)] 和 [Cr(SA)(en)2]Br的合成，表征和动力学性质.docVIP

  Two novel Cr(III) complexes TBA[Cr(SA)2(en)] and [Cr(SA)(en)2]Br：Synthesis, characterization and kinetics properties# 5 10 15 20  Abstract: Two novel Cr(III) complexes TBA[Cr(SA)2(en)] (I) and [Cr(SA)(en)2]Br (II) have been synthesized (TBA=Tetrabutylammonium, H2SA=Salicylic acid, en=ethylenediamine) and determined by X-ray crystallography. The competition reaction with EDTA or apoovotransferrin (apoOTf) was monitored by UV-Visible and fluorescence spectra at 37 °C in 0.01 M Tris-HCl pH=7.4. The rate constant k for the reaction with EDTA is kEDTA(I)=(1.2±0.03)×10-3 and kEDTA(II)=(2.3±0.07)×10-3 M-1S-1, while the rate constant k for the reaction with apoovotransferrin is kOTf(I) =(8.9±0.3)×10-2, kOTf(II)= (1.5±0.07)×10-1 M-1S-1, respectively.The bond length, steric hindrance or electrostatic repulsion is responsable for the different kinetics behavior of the title complexes. Key words: Chromium(III); Salicylic acid; Ovotransferrin; EDTA 0 Introduction Chromium(III), an important part of glucose tolerance, is a necessary microelement, playing an important role in normal physiological function of human bodies[1-5]. Till to now, many chromium(III) complexes were synthesized and fully studied, such as Cr(pic)3[6], [Cr(D-Phe)3][7], NBC[8], CDNC[9], LMWCr[10], Cr-amino acid[11]. However, chromium bioavailability and biological activity are dependent upon the ligand to which chromium is bound [12] have been many proposed chromium complexes for use in dietary, most are inadequate or poorly characterized, and there still remains a need in the art for an improved synthetic chromium 25 30 35 compound, which demonstrates improved biological activity, bioavailability, stability, solubility and/or sensory characteristics[13]. To assess the molecular basis of chromium action in biological systems, many models of non-toxicological action of Cr(III) in biological systems have been advanced recently, such as intracellular mechanisms[4], extracellular model[14], redox mecha