Singlet-Triplet Gaps of Cobalt Nitrosyls: Insights from Tropocoronand Complexes.
Singlet-Triplet Gaps of Cobalt Nitrosyls: Insights from Tropocoronand Complexes.
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亚硝酰钴的单重态-三重态间隙：来自原冠络合物的见解。
DOI：
10.1021/acs.inorgchem.5b00901
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发表时间：
2015
影响因子：
4.6
通讯作者：
Ghosh,Abhik
中科院分区：
文献类型：
--
作者：
Hopmann,KathrinH;Conradie,Jeanet;Tangen,Espen;Tonzetich,ZacharyJ;Lippard,StephenJ;Ghosh,Abhik
用密度泛函理论（DFT）研究了含[n，n]冠醚配体（TC-n，n）的{CoNO} 8亚硝酰基钴配合物，发现随着配合物结构由近四方锥（forn= 3）转变为三角双锥（forn= 5，6），单重态-三重态能隙急剧减小. [Co（TC-3，3）（NO）]的实验重新研究证实，它不像最初报道的那样是顺磁性的，而是反磁性的，像所有其他的{CoNO} 8配合物一样。此外，DFT计算表明该复合物的约半eV或更高的单重态-三重态间隙。在该系列的另一端，低能量，热可及的三重态被预测为[Co（TC-6，6）（NO）]。增强的三重态反应性可能很好地提供了一个失败的部分解释分离这种化合物作为一个稳定的物种。
A density functional theory (DFT) study of {CoNO}8cobalt nitrosyl complexes containing the [n,n]tropocoronand ligand (TC-n,n) has revealed a sharp reduction of singlet–triplet gaps as the structures change from near-square-pyramidal (forn= 3) to trigonal-bipyramidal with an equatorial NO (forn= 5, 6). An experimental reinvestigation of [Co(TC-3,3)(NO)] has confirmed that it is not paramagnetic, as originally reported, but diamagnetic, like all other {CoNO}8complexes. Furthermore, DFT calculations indicate a substantial singlet–triplet gap of about half an eV or higher for this complex. At the other end of the series, low-energy, thermally accessible triplet states are predicted for [Co(TC-6,6)(NO)]. Enhanced triplet-state reactivity may well provide a partial explanation for the failure to isolate this compound as a stable species.