钼(IV,VI)和钨(IV,VI)配合物(Et 4 N)2 [M IV O {1,2-S 2 -3,6-(RCONH)2 C 6 H 2 } 2 ]和( Et 4 N)2 [M VI O 2 {1,2-S 2 -3,6-(RCONH)2 C 6 H 2 } 2 ](M = Mo,W; R =(4- t BuC 6 H 4)3C),合成了具有NH 3 S氢键的大体积疏水性二硫醇盐配体。这些络合物可溶于非极性溶剂(如甲苯),从而可检测溶液中的不对称配位结构和难以捉摸的分子间相互作用。甲苯d 8中配合物的1 H NMR光谱显示不对称配位结构,建议在低温下使抗衡离子接近阴离子部分。钼(IV)配合物与Me 3之间的氧原子转移反应在非极性溶剂中,甲苯中的NO显着加速,并且这种增加归因于底物在疏水环境中有利地接近活性中心。
钼(IV,VI)和钨(IV,VI)配合物(Et 4 N)2 [M IV O {1,2-S 2 -3,6-(RCONH)2 C 6 H 2 } 2 ]和( Et 4 N)2 [M VI O 2 {1,2-S 2 -3,6-(RCONH)2 C 6 H 2 } 2 ](M = Mo,W; R =(4- t BuC 6 H 4)3C),合成了具有NH 3 S氢键的大体积疏水性二硫醇盐配体。这些络合物可溶于非极性溶剂(如甲苯),从而可检测溶液中的不对称配位结构和难以捉摸的分子间相互作用。甲苯d 8中配合物的1 H NMR光谱显示不对称配位结构,建议在低温下使抗衡离子接近阴离子部分。钼(IV)配合物与Me 3之间的氧原子转移反应在非极性溶剂中,甲苯中的NO显着加速,并且这种增加归因于底物在疏水环境中有利地接近活性中心。
reaction. In the case of thiolate Ar1S– containing very bulky acylamino groups forming NH···Shydrogen bonds, the crystal of the intermediate, [Ar1S–I–I]−, was obtained under usual conditions, and the structure was determined by X-ray diffraction analysis. The results show that the intramolecular NH···Shydrogen bonds stabilized the intermediate [Ar1S–I–I]−, consistent with theoretical calculations.
dioxomolybdenum(VI) complexes containing two intramolecularNH···Shydrogen bonds were synthesized and characterized by 1H NMR, UV–visible, IR, and Raman spectroscopies, and electrochemical measurements. Elimination of the steric effects enabled the accurate and quantitative evaluation of NH···Shydrogen bonds. Strong correlations among the strength of the hydrogenbond, the strength of the MoVI═O bond, and the
合成了一系列含有两个分子内NH···S氢键的单氧钼(IV)和二氧钼(VI)配合物,并通过1 H NMR,UV-可见光,IR和拉曼光谱以及电化学测量对其进行了表征。由于消除了空间效应,因此可以准确,定量地评估NH···S氢键。氢键的强度之间的相关性强,则Mo的强度VI = O键,并且氧化还原电位分别清楚地示出。氢键稳定了单氧钼(IV)与Me 3 NO之间反应的中间体,从而导致反应加速或反式顺式延迟重排。在理论计算的基础上讨论了所提出的中间体和反应机理,为反应提供了统一的解释。
Synthesis and structures of soluble magnesium and zinc carboxylates containing intramolecular NH⋯O hydrogen bonds in nonpolar solvents
Magnesium and zinc carboxylates containing intramolecular NH⋯O hydrogen bonds showed a fast trans–cis isomerization in nonpolar solvents and were converted into anionic tris(carboxylate)s by the addition of an equimolar ligand.
Magnesium-dependent phosphatase models containing intramolecular NH...O hydrogen bonds were synthesized and structurally characterized by X-ray analysis. The Mg-O bond distances varied with the mode of the hydrogen bonds. H-1 NMR spectra in nonpolar solvents revealed that the acidity of the coordinated water molecule was regulated by the hydrogen bonds. Further, stoichiometric hydrolysis of phosphoric ester significantly depended on the hydrogen bonds. Zinc analogues showed similar but smaller dependencies, which suggest the indispensable role of Mg2+ ion in the activation of the enzymes.