Tris(pyrazolyl)methanides of the Alkaline Earth Metals: Influence of the Substitution Pattern on Stability and Degradation
作者:Christoph Müller、Alexander Koch、Helmar Görls、Sven Krieck、Matthias Westerhausen
DOI:10.1021/ic5025907
日期:2015.1.20
This expected coordination behavior has been observed for tris(3,4,5-trimethylpyrazolyl)methane (1a), which yields the alkaline-earth-metal bis[tris(3,4,5-trimethylpyrazolyl)methanides] of magnesium (1b), calcium (1c), strontium (1d), and barium (1e) via deprotonation of 1a with dibutylmagnesium and [AeN(SiMe3)2}2] (Ae = Mg, Ca, Sr, and Ba, respectively). Barium complex 1e degrades during recrystallization
三吡唑基甲烷化物通常作为金属离子的强三齿碱。已观察到三(3,4,5-三甲基吡唑基)甲烷(1a)的预期配位行为,产生了镁(1b)的碱土金属双[三(3,4,5-三甲基吡唑基)甲烷]。,钙(1c),锶(1d)和钡(1e)通过二丁基镁和[Ae N(SiMe 3)2 } 2 } 2 ](Ae = Mg,Ca,Sr和Ba分别)对1a进行质子化而得到。钡络合物1e尝试从芳烃和醚中重结晶时发生降解。在这些蝎形配合物中,金属离子嵌入扭曲的八面体配位球中。相反,三(3-噻吩并吡唑基)甲烷(2a)显示出显着不同的反应性。二丁基镁不能使2a去质子化,而[Ae N(SiMe 3)2 } 2 ](Ae = Ca,Sr和Ba)可以平滑地金属化2a。然而,Ca(2c),Sr(2d)和Ba(2e)代表中间体,并在形成碱土金属双(3-噻吩并吡唑酸酯),钙(3c),锶(3d)和钡(3e)并消除四(3-噻吩并吡唑基)乙烯(4