Sheng Weiming, Rajeshkumar Thayalan, Zhao Yue, Maron Laurent, Zhu Congqing
State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
LPCNO, CNRS & INSA, Université Paul Sabatier, 135 Avenue de Rangueil, 31077 Toulouse, France.
J Am Chem Soc. 2024 May 8;146(18):12790-12798. doi: 10.1021/jacs.4c03058. Epub 2024 Apr 29.
Research on metal-metal bonds involving f-block actinides, such as thorium, lags far behind the well-studied metal-metal bonds of d-block transition metals. The complexes with Th-TM bonds are extremely rare; all previously identified examples have only a single Th-TM bond with the Th center at an invariably +IV oxidation state. Herein, we report a series of ThPd ( = 2, 3, and 6) clusters (complexes , , and ) with multiple Th(III)-Pd bonds. Theoretical studies reveal that the ThPd unit allows electronic delocalization and σ aromaticity, leading to unexpected closed-shell singlet structures for these Th(III) species. This electronic delocalization is evident in the highest occupied molecular orbital of Th(III) complexes and facilitates a 2e reduction of alkyne by complex , resulting in the formation of . Complexes and are distinctive in featuring a ThPd core with six and eight Th-Pd bonds, respectively, making them the largest known d-f heterometallic clusters exhibiting metal-metal bonding.
涉及f区锕系元素（如钍）的金属-金属键的研究，远远落后于对d区过渡金属中已充分研究的金属-金属键的研究。含有钍-过渡金属键的配合物极为罕见；所有先前已鉴定出的例子中，钍中心均处于恒定的+IV氧化态，且只有一个钍-过渡金属键。在此，我们报道了一系列具有多个Th(III)-Pd键的ThPd（n = 2、3和6）簇合物（配合物1、2和3）。理论研究表明，ThPd单元允许电子离域和σ芳香性，从而使这些Th(III)物种具有意想不到的闭壳单重态结构。这种电子离域在Th(III)配合物的最高占据分子轨道中很明显，并促进配合物2对炔烃进行2e还原，从而形成产物4。配合物2和3的独特之处在于，它们分别具有含六个和八个Th-Pd键的ThPd核，这使它们成为已知的最大的表现出金属-金属键的d-f异金属簇合物。
