Tsipis Athanassios C, Chaviara Aikaterini Th
Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece.
Inorg Chem. 2004 Feb 23;43(4):1273-86. doi: 10.1021/ic035112g.
Quantum chemical calculations with gradient-corrected (B3LYP) density functional theory for the mono- and bispentazolato complexes of the first row transition metals (V, Cr, Mn, Fe, Co, and Ni), the all-nitrogen counterparts of metallocenes, were performed, and their stability was investigated. All possible bonding modes (e.g. eta1, eta2, eta3, and eta5) of the pentazolato ligand to the transition metals have been examined. The transition metal pentazolato complexes are predicted to be strongly bound molecules. The computed total bond dissociation enthalpies that yield free transition metal atoms in their ground states and the free pentazolato ligands were found in the range of 122.0-201.9 (3.7-102.3) kcal mol(-1) for the bispentazolato (monopentazolato) complexes, while those yielding M2+ and anionic pentazolato ligands were found in the range of 473.2-516.7 (273.6-353.5) kcal mol(-1). The electronic ground states of azametallocenes along with their spectroscopic properties (IR, NMR, and UV-vis) obtained in a consistent manner across the first transition metal series provide means for discussion of their electronic and bonding properties, the identification of the respective azametallocenes, and future laboratory studies. Finally, exploring synthetic routes to azametallocenes it was found that a [2 + 3] cycloaddition of dinitrogen to a coordinated azide ligand with nickel(II) does not seem to provide a promising synthetic route for transition metal pentazolato complexes while the oxidative addition of phenylpentazole and fluoropentazole to Ni(0) bisphosphane complexes merits attention for the experimentalists.
利用梯度校正（B3LYP）密度泛函理论对第一行过渡金属（V、Cr、Mn、Fe、Co和Ni）的单戊唑和双戊唑配合物（茂金属的全氮类似物）进行了量子化学计算，并研究了它们的稳定性。研究了戊唑配体与过渡金属的所有可能键合模式（如η1、η2、η3和η5）。预测过渡金属戊唑配合物是强键合分子。对于双戊唑（单戊唑）配合物，计算得到的产生基态自由过渡金属原子和自由戊唑配体的总键解离焓在122.0 - 201.9（3.7 - 102.3）kcal mol⁻¹范围内，而产生M²⁺和阴离子戊唑配体的总键解离焓在473.2 - 516.7（273.6 - 353.5）kcal mol⁻¹范围内。沿着第一过渡金属系列以一致方式获得的氮杂茂金属的电子基态及其光谱性质（红外、核磁共振和紫外可见）为讨论它们的电子和键合性质、识别各自的氮杂茂金属以及未来的实验室研究提供了手段。最后，在探索氮杂茂金属的合成路线时发现，二氮与镍（II）配位的叠氮配体的[2 + 3]环加成似乎不是过渡金属戊唑配合物的有前景的合成路线，而苯基戊唑和氟戊唑对Ni(0)双膦配合物的氧化加成值得实验人员关注。
