Selective crystallization of four bis(phthalocyaninato)lanthanoid( iii ) polymorphs
Selective crystallization of four bis(phthalocyaninato)lanthanoid( iii ) polymorphs
复制标题
四种双(酞菁)镧系元素( iii )多晶型物的选择性结晶
DOI：
10.1039/d1ce00936b
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发表时间：
2021
期刊：
影响因子：
3.1
通讯作者：
Besson, Claire
中科院分区：
文献类型：
--
作者：
Dailey, Maegan;Besson, Claire
双酞菁稀土配合物（LnPc 2）由于其优异的光学、电学和磁学性质而受到人们的广泛关注。这些化合物的结晶通常需要繁琐的方法，如升华和电结晶，这对结构测定和大规模制备高纯度材料都是一个重大限制。我们在这里报告的选择性结晶LnPc 2的四种多晶型完全通过缓慢蒸发饱和溶液。所获得的相取决于LnPc 2分子的初始氧化态和溶剂的选择。单晶X射线衍射研究确定了Ln = La，Pr，Nd，Sm，Gd，Tb，Dy，Er和Yb等14种新结构，并纠正了文献中的错误鉴定。我们提供了一个详细的比较，在所有的LnPc 2多晶型的分子结构和晶体包装。所有相的主要特征是基于平行π-π相互作用的柱状堆积，在这些堆积内具有各种滑移角以及它们之间的次级相互作用。在重新溶解的晶体上进行的化学氧化还原和酸碱滴定表明，LnPc 2+和LnPc 2 −分别很容易通过弱氧化剂和还原剂获得。此外，我们发现NdPc 2 −络合物的质子化形式与中性NdPc 2具有几乎相同的紫外-可见光谱，解释了先前发表的文献中化学组成的一些混淆。
Bis(phthalocyaninato)lanthanoid(III) (LnPc2) complexes have attracted significant attention for their exceptional optical, electronic and magnetic properties. Crystallization of these compounds usually requires cumbersome methods such as sublimation and electrocrystallization, which is a significant limitation to both structural determinations and the preparation of high purity materials at scale. We report here the selective crystallization of four polymorphs of LnPc2 obtained exclusively by the slow evaporation of saturated solutions. The obtained phase depends on the initial oxidation state of the LnPc2 molecule and the choice of solvent. Single-crystal X-ray diffraction studies were used to determine 14 new structures including Ln = La, Pr, Nd, Sm, Gd, Tb, Dy, Er and Yb, as well as correct previous mis-identifications from the literature. We provide a detailed comparison of molecular structure and crystal packing in all LnPc2 polymorphs. The primary feature in all phases is columnar stacking based on parallel π–π interactions, with a variety of slip angles within those stacks as well as secondary interactions between them. Chemical redox and acid–base titrations, performed on re-dissolved crystals demonstrate that LnPc2+ and LnPc2− are easily obtained through weak oxidizing and reducing agents, respectively. Additionally, we show that the protonated form of the NdPc2− complex has a nearly identical UV-vis spectrum to that of neutral NdPc2, explaining some of the confusion over chemical composition in previously published literature.