论文标题
Tanabe-Sugano d $^6 $图表的修改是由激进配体诱导的:从头算检查Fe(II) - verdazyl分子复合物
Modifications of Tanabe-Sugano d$^6$ diagram induced by radical ligand field: ab initio inspection of a Fe(II)-verdazyl molecular complex
论文作者
论文摘要
在铁(II)[fe(diPyvd)$ _ 2 $] $^{2+} $化合物(dipyvd = 1-异丙基-3,3,3,5-3,5-二皮里迪 - 6-6-氧化二唑)中提出了金属中心和自由基配体之间的量子纠缠。 Wavefunction \ TextIt {ab Initio}(差异专用配置相互作用,DDCI)检查以强调局部自旋状态的多功能性。我们命名了这种现象\ textit {激发态旋转},参考了我们以前的作品(参见Roseiro等人,Chemphyschem 2022,e202200478),我们将旋转旋转概念作为中介症的概念延伸至自由度。局部分子轨道的构建允许阅读波形和投影到局部自旋状态。高能频谱被海森伯格的图片很好地缩短了。 60厘米$^{ - 1} $ Ferromagnetic互动是在激进配体之间计算出的,$ s_ {total} = 0 $和$ 1 $状态在很大程度上由本地的低旋转$ s_ {fe} = 0 $主导。相比之下,上市$ s_ {total} = 2 $状态是本地$ s_ {fe} = 1 $(17%,62%)和$ s_ {fe} = 2 $(72%,21%)旋转状态的叠加。这种混合扩展了高场$ d^6 $ tanabe-sugano图的传统图片。即使在没有自旋轨道耦合的情况下,不同局部自旋状态之间的避免交叉是由自由基配体产生的场触发的。这种令人困惑的场景来自化合物中多功能的局部自旋状态,这些旋转状态在分子磁性中扩展了传统视图。
Quantum entanglement between the spin states of a metal centre and radical ligands is suggested in an iron(II) [Fe(dipyvd)$_2$]$^{2+}$ compound (dipyvd = 1-isopropyl-3,5-dipyridil-6-oxoverdazyl). Wavefunction \textit{ab initio} (Difference Dedicated Configuration Interaction, DDCI) inspections were carried out to stress the versatility of local spin states. We named this phenonmenon \textit{excited state spinmerism}, in reference to our previous work (see Roseiro et. al., ChemPhysChem 2022, e202200478) where we introduced the concept of spinmerism as an extension of mesomerism to spin degrees of freedom. The construction of localized molecular orbitals allows for a reading of the wavefunctions and projections onto the local spin states. The low-energy spectrum is well-depicted by a Heisenberg picture. A 60 cm$^{-1}$ ferromagnetic interaction is calculated between the radical ligands with the $S_{total} = 0$ and $1$ states largely dominated by a local low-spin $S_{Fe} = 0$. In contrast, the higher-lying $S_{total} = 2$ states are superpositions of the local $S_{Fe} = 1$ (17%, 62%) and $S_{Fe} = 2$ (72%, 21%) spin states. Such mixing extends the traditional picture of a high-field $d^6$ Tanabe-Sugano diagram. Even in the absence of spin-orbit coupling, the avoided crossing between different local spin states is triggered by the field generated by radical ligands. This puzzling scenario emerges from versatile local spin states in compounds which extend the traditional views in molecular magnetism.