Binuclear coordination complex of open merocyanine form of photochromic spiropyran with MnII(hfac)2 having high spin (S = 5) ground state
Binuclear coordination complex of open merocyanine form of photochromic spiropyran with MnII(hfac)2 having high spin (S = 5) ground state
复制标题
光致变色螺吡喃的开放部花青形式与具有高自旋 (S = 5) 基态的 MnII(hfac)2 的双核配位络合物
DOI：
10.1039/d3nj00058c
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发表时间：
2023
影响因子：
3.3
通讯作者：
Konarev Dmitri V.
中科院分区：
文献类型：
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作者：
Osipov Nikita G.;Faraonov Maxim A.;Shestakov Alexander F.;Mikhailenko Maxim V.;Kuzmin Alexey V.;Khasanov Salavat S.;Otsuka Akihiro;Yamochi Hideki;Kitagawa Hiroshi;Konarev Dmitri V.
光致变色分子可以通过与金属离子的配位从无色的封闭形式转变为有色的开放形式。在邻二氯苯溶液中，1，3，3-三甲基吲哚啉-β-萘并吡喃螺环（TMI-TBI）与六氟乙酰丙酮锰（II）的相互作用形成深紫红色溶液，表明配位诱导了封闭型向有色开放型的转变.晶体的沉淀产生{Mn II（hfac）2·（μ2-TMI-CH 2）}2二聚体（1），其中六氟乙酰丙酮的两个Mn（II）原子被两个TMI-CH 2配体的氧原子以开放形式桥接。磁性研究表明，MnII自旋之间通过TMI-Dy的氧原子进行弱铁磁交换，估计交换相互作用（J）为+1.07 cm−1。+8 K的正韦斯温度也支持铁磁耦合。结果，MnII自旋在2K下彼此平行排列，并且相应地，这些二聚体转移到高自旋（S = 5）状态。DFT计算支持金属和配体轨道的明显混合以及TMI-Mn配体上的必要正电荷，这可以提供MnII自旋之间的铁磁交换。
Photochromic molecules can transform from colorless closed to colored open forms by coordination with metal ions. Interaction of photochromic 1,3,3-trimethylindolino-β-naphthopyrylospiran (TMI-NPS) with manganese(II) hexafluoroacetylacetonate in o-dichlorobenzene results in the formation of deep red-violet solution indicating a coordination-induced transition from closed to colored open form. Precipitation of crystals yields {MnII(hfac)2·(μ2-TMI-NPS)}2 dimers (1) in which two Mn(II) atoms of hexafluoroacetylacetonate are bridged by oxygen atoms of two TMI-NPS ligands in the open form. Magnetic studies show a weak ferromagnetic exchange between MnII spins through oxygen atoms of TMI-NPS with estimated exchange interaction (J) of +1.07 cm−1. A positive Weiss temperature of +8 K also supports ferromagnetic coupling. As a result, MnII spins arrange parallel to each other at 2 K, and correspondingly, these dimers transfer to a high spin (S = 5) state. DFT calculations support noticeable mixing of the metal and ligand orbitals and essential positive charge on the TMI-NPS ligands, which can provide ferromagnetic exchange between MnII spins.