The inverse-trans-influence in tetravalent lanthanide and actinide bis(carbene) complexes.
The inverse-trans-influence in tetravalent lanthanide and actinide bis(carbene) complexes.
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DOI：
10.1038/ncomms14137
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发表时间：
2017-02-03
影响因子：
16.6
通讯作者：
Liddle ST
中科院分区：
文献类型：
--
作者：
Gregson M;Lu E;Mills DP;Tuna F;McInnes EJ;Hennig C;Scheinost AC;McMaster J;Lewis W;Blake AJ;Kerridge A;Liddle ST
在整个元素周期表中，反式影响起作用，即紧密结合的配体选择性地延长相互反式金属-配体键。相反，在高氧化态的锕系配合物中，反反式影响起作用，通常是顺式强供体的配体反而是反式的，实际上是相互增强的。然而，由于反式影响仅限于高价actin和一些铀（V/VI）配合物，因此在一个几乎没有统一规则的领域，它的范围有限。在这里，我们报告了具有反式C=M=C核心的四价铈、铀和钍二（碳）配合物，其中实验和理论数据表明存在反式影响。对假设的镨（IV）和铽（IV）类似物的研究表明，反向反式影响可能延伸到这些离子，但随着4f轨道的填充，这种影响也显著减弱。这项工作表明，反向反式影响可能发生在高氧化态5f金属之外，因此可能包括中等氧化态的锕系元素和镧系元素。因此，反反影响可能是一个更普遍的f块原则。反式影响已被证明在高氧化态锕系配合物中起作用。在这里，作者报告了具有反式C=M=C核心的四价铈、铀和钍二（碳）配合物，实验和理论数据也表明存在反式效应。
Across the periodic table the trans-influence operates, whereby tightly bonded ligands selectively lengthen mutually trans metal–ligand bonds. Conversely, in high oxidation state actinide complexes the inverse-trans-influence operates, where normally cis strongly donating ligands instead reside trans and actually reinforce each other. However, because the inverse-trans-influence is restricted to high-valent actinyls and a few uranium(V/VI) complexes, it has had limited scope in an area with few unifying rules. Here we report tetravalent cerium, uranium and thorium bis(carbene) complexes with trans C=M=C cores where experimental and theoretical data suggest the presence of an inverse-trans-influence. Studies of hypothetical praseodymium(IV) and terbium(IV) analogues suggest the inverse-trans-influence may extend to these ions but it also diminishes significantly as the 4f orbitals are populated. This work suggests that the inverse-trans-influence may occur beyond high oxidation state 5f metals and hence could encompass mid-range oxidation state actinides and lanthanides. Thus, the inverse-trans-influence might be a more general f-block principle. The inverse-trans-influence has been shown to operate in high oxidation state actinide complexes. Here, the authors report tetravalent cerium, uranium and thorium bis(carbene) complexes with trans C=M=C cores where experimental and theoretical data also suggest the presence of an inverse-trans-effect.