The dissociation constants of 3,5-dimethyl-D,L-tyrosine(Dmtyr) and other three kinds of aromatic diamine as phen、bpy and en were determined by potentiometric method,using an automatic METERLER DL-21 titration,at 25℃...The dissociation constants of 3,5-dimethyl-D,L-tyrosine(Dmtyr) and other three kinds of aromatic diamine as phen、bpy and en were determined by potentiometric method,using an automatic METERLER DL-21 titration,at 25℃ and the ionic strengh of 0.1mol/L NaNO3 in solution.The stability constants of the corresponding binary complexes and the ternary complexes of Cu(Dmty)(DA)(DA=phen、bpy and en) were also determined under the same condition.ΔlogK、logX values were calculated and the effect factors of extra stability were analyzed.The dissociation constants of Dimt and the stability constants of the Cu(Dmtyr)2,Cu(Dmtyr)(DA)(DA =phen,bpy and en) were unreported.It was found that methyl show less effect on the dissociation of 4-hydroxyl group,however,in complexes methyl may enhance the static and hydrogen bond formation of 4-hydroxy group.1H-NMR of Cu(Dmtyr)(phen) was determined,the chemical displacements of aromatic hydrogen and methylic hydrogen were observed,which offered the evidence of ligand-ligand interaction.展开更多
文摘The dissociation constants of 3,5-dimethyl-D,L-tyrosine(Dmtyr) and other three kinds of aromatic diamine as phen、bpy and en were determined by potentiometric method,using an automatic METERLER DL-21 titration,at 25℃ and the ionic strengh of 0.1mol/L NaNO3 in solution.The stability constants of the corresponding binary complexes and the ternary complexes of Cu(Dmty)(DA)(DA=phen、bpy and en) were also determined under the same condition.ΔlogK、logX values were calculated and the effect factors of extra stability were analyzed.The dissociation constants of Dimt and the stability constants of the Cu(Dmtyr)2,Cu(Dmtyr)(DA)(DA =phen,bpy and en) were unreported.It was found that methyl show less effect on the dissociation of 4-hydroxyl group,however,in complexes methyl may enhance the static and hydrogen bond formation of 4-hydroxy group.1H-NMR of Cu(Dmtyr)(phen) was determined,the chemical displacements of aromatic hydrogen and methylic hydrogen were observed,which offered the evidence of ligand-ligand interaction.
