School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
Institute of Inorganic Chemistry, University of Regensburg, Universitätsstr.31, Regensburg 93053, Germany.
Nat Commun. 2017 Mar 9;8:14769. doi: 10.1038/ncomms14769.
Despite a major expansion of uranium-ligand multiple bond chemistry in recent years, analogous complexes involving other actinides (An) remain scarce. For thorium, under ambient conditions only a few multiple bonds to carbon, nitrogen, phosphorus and chalcogenides are reported, and none to arsenic are known; indeed only two complexes with thorium-arsenic single bonds have been structurally authenticated, reflecting the challenges of stabilizing polar linkages at the large thorium ion. Here, we report thorium parent-arsenide (ThAsH), -arsinidiides (ThAs(H)K and ThAs(H)Th) and arsenido (ThAsTh) linkages stabilized by a bulky triamidoamine ligand. The ThAs(H)K and ThAsTh linkages exhibit polarized-covalent thorium-arsenic multiple bonding interactions, hitherto restricted to cryogenic matrix isolation experiments, and the AnAs(H)An and AnAsAn linkages reported here have no precedent in f-block chemistry. 7s, 6d and 5f orbital contributions to the Th-As bonds are suggested by quantum chemical calculations, and their compositions unexpectedly appear to be tensioned differently compared to phosphorus congeners.
尽管近年来铀配体多重键化学有了重大扩展，但涉及其他锕系元素（An）的类似配合物仍然很少。对于钍，在环境条件下，仅报道了与碳、氮、磷和硫属元素的少数多重键，而没有与砷的多重键；实际上，仅通过结构确证了两个具有钍-砷单键的配合物，这反映了在大的钍离子稳定极性键合的挑战。在这里，我们报告了由庞大的三氨基胺配体稳定的钍砷化物（ThAsH）、-砷化物（ThAs（H）K 和 ThAs（H）Th）和砷化物（ThAsTh）键。ThAs（H）K 和 ThAsTh 键表现出极化共价的钍-砷多重键合相互作用，迄今为止仅限于低温基质隔离实验，而这里报道的 AnAs（H）An 和 AnAsAn 键在 f 区化学中没有先例。量子化学计算表明，7s、6d 和 5f 轨道对 Th-As 键的贡献，其组成出人意料地与磷同系物不同。
