Complexes of pyridoxal thiosemicarbazones formed with vanadium(IV/V) and copper(II): Solution equilibrium and structure
作者:Tamás Jakusch、Károly Kozma、Éva A. Enyedy、Nóra V. May、Alexander Roller、Christian R. Kowol、Bernhard K. Keppler、Tamás Kiss
DOI:10.1016/j.ica.2017.08.018
日期:2018.3
pyridoxal moiety of the ligand causes an extra deprotonation step between pH 4 and 7 due to the non-coordinating pyridine-NH + . The pyridoxal-containing ligands form somewhat more stable complexes with both V IV O and Cu II ions than the reference compound salicylaldehyde thiosemicarbazone. Dimethylation of the terminal amino group resulted in the formation of V V and Cu II complexes with even higher stability
摘要通过pH-电位法(V IV O),EPR(V IV O)测定了吡ido醛硫代半碳酸钠和吡ido醛-N 3,N 3-二甲基硫代氨基脲的钒(IV / V)和铜(II)配合物的化学计量和热力学稳定性。 / Cu II),UV-Vis(Cu II,V IV O和VV)和51 V NMR光谱(VV)在30%(w / w)的二甲亚砜/水溶剂混合物中进行。在所有情况下,单配体络合物均以不同的质子化状态形成。此外,配体的质子离解常数还通过pH电位法,UV-Vis和1 H NMR光谱法测定。通过单晶X射线衍射分析表征了VV配合物的单质子化形式的固态结构(VVO 2(L 1 H)×1.5H 2 O和VVO 2(L 2 H)×0.8H 2 O)。 。Cu II和VV的单配体络合物在生理pH值上占主导地位。对于所有研究的金属离子,由于非配位吡啶-NH +,配体的吡pyr醛部分在pH 4和7之间引起额外的去质子化步骤。含吡咯醛的配体与V