Passadis Stamatis S, Papanikolaou Michael G, Elliott Alexander, Tsiafoulis Constantinos G, Tsipis Athanassios C, Keramidas Anastasios D, Miras Haralampos N, Kabanos Themistoklis A
West CHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ, U.K.
Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus.
Inorg Chem. 2020 Dec 21;59(24):18345-18357. doi: 10.1021/acs.inorgchem.0c02959. Epub 2020 Dec 8.
The chelating catechol/oxime ligand 2,3-dihydroxybenzaldehyde oxime (Hdihybo) has been used to synthesize one titanium(IV) and two zirconium(IV) compounds that have been characterized by single-crystal X-ray diffraction and H and C NMR, solid-state UV-vis, and ESI-MS spectroscopy. The reaction of TiCl with Hdihybo and KOH in methanol, at ambient temperature, yielded the hexanuclear titanium(IV) compound K[Ti(μ-O)(μ-O)(OCH)(CHOH)(μ-Hdihybo)]·CHOH (), while the reaction of ZrCl with Hdihybo and either BuNOH or KOH also gave the hexanuclear zirconium(IV) compounds and , respectively. Compounds - have the same structural motif [M(μ-Ο)(μ-Ο)] (M = Ti, Zr), which constitutes a unique example with a trigonal-prismatic arrangement of the six zirconium atoms, in marked contrast to the octahedral arrangement of the six zirconium atoms in all the Zr clusters reported thus far, and a unique Zr core structure. Multinuclear NMR solution measurements in methanol and water proved that the hexanuclear clusters and retain their integrity. The marriage of the catechol moiety with the oxime group in the ligand Hdihybo proved to be quite efficient in substantially reducing the band gaps of TiO and ZrO to 1.48 and 2.34 eV for the titanium and zirconium compounds and , respectively. The application of and in photocurrent responses was investigated. ESI-MS measurements of the clusters and revealed the existence of the hexanuclear metal core and also the initial formation of trinuclear M (M = Ti, Zr) building blocks prior to their self-assembly into the hexanuclear M (M = Ti, Zr) species. Density functional theory (DFT) calculations of the NICS scan curves of these systems revealed that the triangular M (M = Ti, Zr) metallic ring cores exhibit pronounced metalloaromaticity. The latter depends upon the nature of the metallic center with NICS(1) values equal to -30 and -42 ppm for the Ti (compound ) and Zr (compound ) systems, respectively, comparable to the NICS(1) value of the benzene ring of -29.7 ppm calculated at the same level of theory.
螯合邻苯二酚/肟配体2,3 - 二羟基苯甲醛肟（Hdihybo）已被用于合成一种钛（IV）化合物和两种锆（IV）化合物，这些化合物已通过单晶X射线衍射、氢和碳核磁共振、固态紫外可见光谱以及电喷雾电离质谱进行了表征。在室温下，TiCl与Hdihybo和KOH在甲醇中反应，生成了六核钛（IV）化合物K[Ti(μ - O)(μ - O)(OCH)(CHOH)(μ - Hdihybo)]·CHOH（），而ZrCl与Hdihybo和BuNOH或KOH反应，分别生成了六核锆（IV）化合物和。化合物 - 具有相同的结构单元[M(μ - Ο)(μ - Ο)]（M = Ti，Zr），这构成了一个独特的例子，六个锆原子呈三角棱柱排列，这与迄今为止报道的所有Zr簇中六个锆原子的八面体排列形成显著对比，并且具有独特的Zr核心结构。在甲醇和水中进行的多核核磁共振溶液测量证明，六核簇和保持了它们的完整性。配体Hdihybo中邻苯二酚部分与肟基团的结合被证明在将TiO和ZrO的带隙分别大幅降低至1.48和2.34 eV方面非常有效，这分别对应于钛和锆的化合物和。研究了和在光电流响应中的应用。对簇和的电喷雾电离质谱测量揭示了六核金属核心的存在，以及在它们自组装成六核M（M = Ti，Zr）物种之前三核M（M = Ti，Zr）结构单元的初始形成。对这些体系的核独立化学位移（NICS）扫描曲线进行密度泛函理论（DFT）计算表明，三角形M（M = Ti，Zr）金属环核心表现出明显的金属芳香性。后者取决于金属中心的性质，对于Ti（化合物）和Zr（化合物）体系，NICS(1)值分别等于 - 30和 - 42 ppm，与在相同理论水平下计算的苯环的NICS(1)值 - 29.7 ppm相当。
