Synthesis, structural characterization, and reactivity of a dinuclear cobalt(II) (μ-hydroxo)(μ-pyrazolato) complex based on a hydrotris(pyrazolyl)borate ligand
Synthesis, structural characterization, and reactivity of a dinuclear cobalt(II) (μ-hydroxo)(μ-pyrazolato) complex based on a hydrotris(pyrazolyl)borate ligand
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基于氢化三(吡唑基)硼酸酯配体的双核钴(II)(μ-羟基)(μ-吡唑基)络合物的合成、结构表征和反应性
DOI：
10.1016/j.ica.2021.120533
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发表时间：
2021
影响因子：
2.8
通讯作者：
Hikichi Shiro
中科院分区：
文献类型：
--
作者：
Komatsuzaki Hidehito;Ohira Kazunari;Tadokoro Shun;Yamasaki Yuta;Oouchi Hitomi;Satoh Minoru;Agou Tomohiro;Tanaka Yuya;Akita Munetaka;Nakazawa Jun;Hikichi Shiro
合成了一个双核（μ-羟基）（μ-吡唑）二钴（Ⅱ）与三（3，5-二异丙基-1-吡唑基）硼酸氢盐（TpiPr）的配合物[Co Ⅱ（TpiPr）]2（μ-OH）（μ-Pz）（8），并对其结构进行了表征. X射线衍射分析表明，配合物8具有对称面，两个钴离子呈现畸变的五配位结构，即分别与μ-OH桥连配体中的一个氧原子和TpiPr配体及μ-Pz桥连配体中的四个氮原子配位. Co 1-O 1（1.966（2））和Co 1-N3（2.085（4），其中N3来自μ-Pz）的键长短于先前报道的二锰（II）类似物配合物的Mn-O（2.075（5）和2.047（5））和Mn-N（2.160（5）和2.215（6））的键长，这是由于钴（II）的较强的刘易斯酸性。配合物8与CO2反应，得到双核钴（II）μ-碳酸根配合物7。在与乙酸4-硝基苯酯反应的情况下，生成单核钴（II）4-硝基苯氧配合物，其在钴（II）中心上具有3，5-二异丙基吡唑（PzH），[CoII（PzH）（TpiPr）（OC 6 H4 - 4 NO2）]（9），因此作为水解酶的重要模型。
A dinuclear (μ-hydroxo)(μ-pyrazolato)dicobalt(II) complex with hydrotris(3,5-diisopropyl-1-pyrazolyl)borate (TpiPr), [CoII(TpiPr)]2(μ-OH)(μ-Pz) (8), was synthesized and structurally characterized, showing that the metal-hydroxide moiety acts as a nucleophile toward 4-nitrophenyl acetate and CO2, similarly to metalloenzymes. The X-ray analysis revealed that the complex8has a symmetry plane and that its two cobalt ions present distorted five-coordinated structures, that is, each of them is coordinated to one oxygen atom from the bridgingμ-OH ligand and four nitrogen atoms from the TpiPrligand and the bridgingμ-Pz ligand. The Co1–O1 (1.966(2) Å) and Co1–N3 (2.085(4) Å, where N3 is fromμ-Pz) bond lengths are shorter than the Mn–O (2.075(5) and 2.047(5) Å) and Mn–N (2.160(5) and 2.215(6) Å) ones of the previously reported dimanganese(II) analog complex due to the stronger Lewis acidity of cobalt(II). Upon reaction of the complex8with CO2, a dinuclear cobalt(II)μ-carbonato complex7was obtained. In case of reaction with 4-nitrophenyl acetate, a mononuclear cobalt(II) 4-nitrophenoxo complex with 3,5-diisopropylpyrazole (PzH) on the cobalt(II) center, [CoII(PzH)(TpiPr)(OC6H4-4NO2)] (9), was generated, thus serving as an important model for hydrolase enzyme.