Oxo–tungsten bis-dithiolene complexes relevant to tungsten centres in enzymes
Oxo–tungsten bis-dithiolene complexes relevant to tungsten centres in enzymes
复制标题
与酶中钨中心相关的氧代-双二硫醇钨络合物
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
C. Garner
中科院分区：
文献类型：
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作者：
E. Davies;Georgina M. Aston;R. Beddoes;D. Collison;A. Dinsmore;A. Docrat;J. Joule;Clare R. Wilson;C. Garner
[WO_2(CN)_4]_4-与一系列二甲氨基或硫酮保护的不对称二硫杂环戊烯(烯-1，2-二硫醇酸盐)反应，合成了[WO(二硫杂环烯)_2]_2-络合物(二硫杂环烯=1-SC(H)C(R)S-，R=苯基，吡啶-2-基，吡啶-3-基，吡啶-4-基或喹恶啉-2-基)，经元素分析、光谱和电化学表征。典型化合物[PPh_4]_2[WO(Sdt)_2]·Etoh[Sdt_2=-Sc(H)C(Ph)S~-]属于P21/c空间群，晶胞参数为a_(β)=13.242(4)，b_c=31.894(8)，c_c=14.589(5)A，WO_4=31.894(2)°，Z_0=14.589(5)°。WOS4部分为四方锥体，顶端为O原子[WO 1.724(7)A，W-Sav 2.37 A，WO 1.724(7)A，W-SaV 2.37 A，O-W-SAV 108.7°]，并含有苯基的顺式构型，尽管1H核磁共振研究表明分离的固体中既存在顺式异构体，也存在反式异构体。所有[WO(二硫代茂)2]2-络合物的物理性质都与WIVOS4中心的保留一致，每个体系都经历了可逆的电化学单电子氧化到相应的WV体系。通过考虑芳基取代基的性质，可以合理地解释WV-wiv对的ν(WO)和ν(CC)(Dithiolene)IR伸缩频率、1H核磁共振波谱和Eü值的变化。这些数据与类似的MoIV络合物的数据以及钨酶及其氧钼多酶对应物的催化中心的数据进行了比较。
The reaction of [WO2(CN)4]4– with a series of dimethylamino- or thione-protected asymmetric dithiolenes (ene-1,2-dithiolates) has been used to synthesise [WO(dithiolene)2]2– complexes (dithiolene = –SC(H)C(R)S–, R = phenyl, pyridin-2-yl, pyridin-3-yl, pyridin-4-yl or quinoxalin-2-yl), which have been characterised by elemental analysis, spectroscopy and electrochemistry. The prototypical compound [PPh4]2[WO(sdt)2]·EtOH [sdt = styrenedithiolate, –SC(H)C(Ph)S–], crystallises in space group P21/c with a = 13.242(4), b = 31.894(8), c = 14.589(5) A, β = 113.80(2)°, and Z = 4. The WOS4 moiety is square-based pyramidal with the O atom at the apex [WO 1.724(7) A, W–Sav 2.37 A, O–W–Sav 108.7°] and contains a cis geometry of the phenyl groups, although 1H NMR studies indicate that both cis and trans isomers are present in the isolated solid. The physical properties of all of the [WO(dithiolene)2]2– complexes are consistent with a retention of the WIVOS4 centre and each system undergoes a reversible electrochemical one-electron oxidation to the corresponding WV system. The variation in the dithiolene 1H NMR resonances, ν(WO) and ν(CC) (dithiolene) IR stretching frequencies, and the E½ values for the WV–WIV couple can be rationalised by a consideration of the nature of the aryl substituent. These data are compared to those of the analogous MoIV complexes and to those of the catalytic centres of the tungstoenzymes and their oxomolybdoenzyme counterparts.
荚膜红杆菌二甲亚砜还原酶的晶体结构，分辨率为 1.88 A。
影响因子：
5.6
作者：
Schneider,F;Löwe,J;Huber,R;Schindelin,H;Kisker,C;Knäblein,J
通讯作者：
Knäblein,J