precatalyst of ultrathin metal–organic nanosheets Co-SeMON, is revealed to significantly enhance the catalytic mass activity of the cobalt site by 25 times, as well as extend the catalyst operation time in alkaline conditions by 1 or 2 orders of magnitude compared with these reported metal selenides. A combination of various in situ/ex situ spectroscopic techniques, ab initio molecular dynamics, and
重塑金属活性位点的反应性对于促进可再生电力水电解至关重要。将杂原子(例如 Se)掺杂到金属晶格中被认为是一种有效的方法,但在苛刻的电催化条件下通常会损失功能性杂原子,从而导致催化剂逐渐失活。在这里,我们报告了一种新的含杂原子的分子增强策略,以实现可持续的氧气释放改进。有机硒配体,bis(3,5-dimethyl-1 H-pyrazol-4-yl)selenide 含有强大的 C-Se-C 共价键,配备在超薄金属-有机纳米片 Co-SeMON 的预催化剂中,显着提高了钴位点的催化质量活性 25 倍,以及与这些报道的金属硒化物相比,将碱性条件下的催化剂运行时间延长 1 或 2 个数量级。各种原位/非原位的组合光谱技术、从头算分子动力学和密度泛函理论计算揭示了有机硒强化机制,其中 Se 与含 O 中间体的非经典键合赋予了超越传统比例关系的吸附能量调节。我们的结果展示了分子增强催化剂在高效和经济的水氧化方面的巨大潜力。
Bis(3,5-dimethyl-1H-pyrazolyl)selenide – a new bidentate bent connector for preparation of 1D and 2D co-ordination polymers
作者:Maksym Seredyuk、Matti Haukka、Igor O. Fritsky、Henryk Kozłowski、Roland Krämer、Vadim A. Pavlenko、Philipp Gütlich
DOI:10.1039/b702574b
日期:——
The synthesis and description of eight polymeric complexes formed by transition metals with the bifurcated ligand bis(3,5-dimethyl-1H-pyrazolyl)selenide are discussed together with X-ray crystal analysis as well as variable temperature magnetic susceptibility and characterization by Mössbauer spectroscopy. Preferable types of binding patterns of the ligand were determined, which include a variation of the bridging modes (cis- and trans-) and of the separation length, where the latter parameter together with bending of the ligand molecule were found to be dependent on the type of co-ordination geometry of the central atom and the nature of the anion. A strategy for increasing the structure dimensionality was explored using bridging properties of anions yielding 2D hybrid organic-inorganic polymers.
New reaction of 1H-pyrazoles with selenium dioxide: one-pot synthesis of bis(1H-pyrazol-4-yl)selenides
作者:Maksym Seredyuk、Igor O. Fritsky、Roland Krämer、Henryk Kozłowski、Matti Haukka、Philipp Gütlich
DOI:10.1016/j.tet.2010.08.071
日期:2010.11
A novel reaction between 3- and 3,5-substituted pyrazoles with selenium dioxide proceeds with formation of bis(3R,5R′-1H-pyrazol-4-yl)selenides in high yield. On this basis, an efficient one-pot synthetic procedure has been developed. In the case of the unsubstituted pyrazole a selenonium compound has been obtained. The identity and structure of the isolated selenium derivatives have been confirmed