Department of Chemistry, University of Zurich, Zurich CH-8057, Switzerland.
Department of Chemistry, University of Central Florida, 4111 Libra Drive, Orlando, Florida 32816, United States.
Inorg Chem. 2023 Jul 10;62(27):10727-10735. doi: 10.1021/acs.inorgchem.3c01177. Epub 2023 Jun 23.
Metal-ligand cooperativity is a powerful tool for the activation of various bonds but has rarely, if ever, been studied with the radioactive transition metal Tc. In this work, we explore this bond activation pathway with the dearomatized PNP complex -[Tc(PNP*)(CO)] (), which was synthesized by deprotonation of -[Tc(PNP)(CO)Cl] with KOBu. Analogous to its rhenium congener, the dearomatized compound reacts with CO to form the carboxy complex -[Tc(PNP-COO)(CO)] and with H to form the mono-hydride complex -[Tc(PNP)(CO)H] (). Substrates with weakly acidic protons are deprotonated by the Brønsted basic pincer backbone of , yielding a variety of intriguing complexes. Reactions with terminal alkynes enable the isolation of acetylide complexes. The deprotonation of an imidazolium salt results in the in situ formation and coordination of a carbene ligand. Furthermore, a study with heterocyclic substrates allowed for the isolation of pyrrolide and pyrazolide complexes, which is uncommon for Tc. The spectroscopic analyses and their solid-state structures are reported.
金属-配体协同作用是激活各种键的有力工具，但很少（如果有的话）用放射性过渡金属 Tc 进行研究。在这项工作中，我们通过去芳构化的 PNP 配合物-Tc(PNP*)(CO)来探索这种键激活途径，该配合物是通过 KOBu 对-[Tc(PNP)(CO)Cl]进行脱质子化合成的。与铼同系物类似，去芳构化的化合物与 CO 反应形成羧酸配合物-[Tc(PNP-COO)(CO)]，与 H 反应形成单氢化物配合物-Tc(PNP)(CO)H。具有弱酸性质子的底物被,的 Brønsted 碱性钳形骨架脱质子化，生成各种有趣的配合物。与末端炔烃的反应可以分离得到炔化物配合物。咪唑盐的脱质子化导致卡宾配体的原位形成和配位。此外，对杂环底物的研究允许分离出通常在 Tc 中罕见的吡咯烷和吡唑烷配合物。报道了光谱分析及其固态结构。
