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Synthesis, Crystal Structure of Cis ‐dioxo‐catecholatotungsten(VI) Complex and Its NMR Studies on the Interaction with ATP
Author(s) -
XiaoMing Lu,
ShunCheng Liu,
Ling Jiang,
XiAn Mao,
ZhaoHui Ye
Publication year - 2003
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.20030210614
Subject(s) - chemistry , molybdenum , electron paramagnetic resonance , protonation , nmr spectra database , ligand (biochemistry) , crystallography , crystal structure , octahedron , proton nmr , ethylenediamine , redox , nuclear magnetic resonance spectroscopy , stereochemistry , inorganic chemistry , spectral line , ion , organic chemistry , nuclear magnetic resonance , biochemistry , physics , receptor , astronomy
Cis ‐dioxo‐catecholatotungsten(VI) complex anion [W (VI) O 2 ‐(OC 6 H 2 O)] 2‐ was obtained with discrete protonated ethylene‐diamine (NH 2 CH 2 CH 2 NH 3 ) + cations by the reaction of tetra‐butyl ammonium decatungstate with catechol in the mixed solvent of CH 3 OH, CH 3 CN and ethylenediamine, and compared with its molybdenum analogue [Mo (v) O2(OC 6 H 4 O)2] 3‐ by crystal structure, UV, EPR. The results of the UV and EPR spectra show that tungsten is less redox active than molybdenum since the molybdenum is reduced from Mo(VI) to Mo(V) but tungsten stays in the original highest oxidized state Mo (VI) when they are crystallized from the solution above. It is worthy to note that [W (VI) O 2 (OC 6 H 4 O 2 )] 2‐ shows the same coordination structure as its molybdenum analogue in which the metal center exhibits distorted octahedral coordination geometry with two cis ‐dioxocatecholate ligands and might have the related coordination structure feature with the cofactor of flavoenzyme because [Mo (v) O 2 (OC 6 H 4 O) 2 ] 3‐ presented essentially the same EPR spectra as flavoenzyme. The NMR studies on the interaction of the title complex with ATP reveal that the reduction of W(VI) to W(V) occurs when the title complex is dissolved in D 2 O and the W (V) is oxidized again when ATP solution is mixed with original solution and the hydrolysis of the catechola‐to ligand take places at mean time being monitored by 1 H NMR and 13 C NMR spectra.