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Title: Selective crystallization of four bis(phthalocyaninato)lanthanoid( iii ) polymorphs
Bis(phthalocyaninato)lanthanoid( iii ) (LnPc 2 ) 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 LnPc 2 obtained exclusively by the slow evaporation of saturated solutions. The obtained phase depends on the initial oxidation state of the LnPc 2 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 LnPc 2 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 LnPc 2 + and LnPc 2 − are easily obtained through weak oxidizing and reducing agents, respectively. Additionally, we show more » that the protonated form of the NdPc 2 − complex has a nearly identical UV-vis spectrum to that of neutral NdPc 2 , explaining some of the confusion over chemical composition in previously published literature. « less
Authors:
;
Award ID(s):
1800108
Publication Date:
NSF-PAR ID:
10353308
Journal Name:
CrystEngComm
Volume:
23
Issue:
40
Page Range or eLocation-ID:
7151 to 7161
ISSN:
1466-8033
Sponsoring Org:
National Science Foundation
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