Metallacarboranes with a Greek letter θ shape like [Co(C 2 B 9 H 11 ) 2 ] - have been tested, for the first time, as efficient photoredox catalysts in the oxidation of aromatic and aliphatic alcohols in water. The efficiency displayed by them is linked to their high solubility in water, their high oxidizing power ( Co 4+/3+ ), and their absence of fluorescence upon excitation, among others. In most of the studied examples, using a catalyst load of 0,4 mol %, high yields near 90-95% have been obtained, with selectivity values >99%. By reducing the catalyst load to 0,01 mol %, quantitative conversion of reactants into products have been achieved, in some cases over 99% yield, exhibiting the catalyst high efficiency to reach TON=10000, and proving that a higher yield is achieved with 45 times less concentrated catalyst. Metallacarboranes can be recovered easily by precipitation upon the addition of [NMe 4 ]Cl. Further a postulated pathway for the photoredox catalyzed oxidation of alcohols has been proposed.

中文翻译：

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金属碳硼烷在水中作为光氧化还原催化剂。

具有希腊字母θ形状的金属碳碳素（如[Co（C 2 B 9 H 11）2]）已首次作为有效的光氧化还原催化剂在水中芳族和脂族醇的氧化中进行了测试。它们显示出的效率与其在水中的高溶解度，其高氧化能力（Co 4 + / 3 +），以及在激发时不存在荧光有关。在大多数研究的实施例中，使用0.4摩尔％的催化剂负载量，获得了接近90-95％的高产率，选择性值＞ 99％。通过将催化剂负载降低至0.01 mol％，已实现了反应物向产物的定量转化，在某些情况下，收率超过99％，显示出催化剂的高效率，达到TON = 10000，并证明了获得更高的收率。浓缩催化剂少45倍。通过加入[NMe 4] Cl可以通过沉淀容易地回收金属碳硼烷。进一步提出了光氧化还原催化的醇氧化的假定途径。