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1. Selective crystallization of four bis(phthalocyaninato)lanthanoid( iii ) polymorphs

   https://doi.org/10.1039/d1ce00936b  

   Dailey, Maegan; Besson, Claire (October 2021, CrystEngComm)

   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 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. 

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2. Crystallization and Mechanical Properties of Poly( l -lactide)-Based Rubbery/Semicrystalline Multiblock Copolymers

   https://doi.org/10.1021/acs.macromol.5b01029  

   Panthani, Tessie R.; Bates, Frank S. (July 2015, Macromolecules)
3. Crystallization of Poly( l -lactic acid) on Water Surfaces via Controlled Solvent Evaporation and Langmuir–Blodgett Films

   https://doi.org/10.1021/acs.langmuir.3c03788  

   Qian, Qian; Furner, Carl T; Li, Christopher Y (March 2024, Langmuir)
4. Limits to Crystallization Pressure

   https://doi.org/10.1021/acs.langmuir.2c01325  

   Li, Lei; Kohler, Felix; Dziadkowiec, Joanna; Røyne, Anja; Espinosa Marzal, Rosa M.; Bresme, Fernando; Jettestuen, Espen; Dysthe, Dag Kristian (September 2022, Langmuir)
5. Crystallization‐driven Nanoparticle Crystalsomes

   https://doi.org/10.1002/anie.202217267  

   Gao, Lingfeng; Mei, Shan; Qian, Qian; Yu, Shichen; Zhao, Bin; Tu, Yingfeng; Li, Christopher Y. (February 2023, Angewandte Chemie International Edition)

   Abstract Nanoparticle (NP) assembly has been extensively studied, and a library of NP superstructures has been synthesized. These intricate structures show unique collective optical, electronic, and magnetic properties. In this work, we report a bottom‐up approach for fabricating spherical gold nanoparticle (AuNP) assemblies that mimic colloidosomes. Co‐crystallization of lipoic acid‐end‐functionalized poly(ethylene oxide) (PEO) and AuNPs in solution via a self‐seeding method led to the formation of hollow spherical NP assemblies named nanoparticle crystalsomes (NPCs). Due to the spherical shape, the translational symmetry of PEO crystals is broken in NPCs, which can be attributed to the competition between NP close packing and polymer crystallization. This was confirmed by tuning the NPC morphology via varying the self‐seeding temperature, crystallization temperature, and PEO molecular weight. We envisage that this strategy paves the way to attaining exquisite morphological control of NP assemblies with broken translational symmetry. 

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