A bis-urea naphthalene macrocycle displaying two crystal structures with parallel ureas

Geer, Michael F.; Smith, Mark D.; Shimizu, Linda S.

doi:10.1039/c1ce05207a

Cited by 4 publications

(6 citation statements)

References 24 publications

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“…It has been suggested that syn-parallel tapes are less favorable than antiparallel networks as a result of destabilizing dipole interactions between neighboring ureas. 87 However, examination of bis(urea) crystal structures in the CSD 84 (Table S2) reveals that around 40% of bis(urea)s with urea-urea interactions exhibit a parallel intramolecular arrangement of urea groups (Table S3). Indeed, although structure III lacks the additional interlamellar hydrogen bonding of structure II, its density is 3% higher as a result of more efficient interdigitation of neighboring lamellae (d layer = 10.857(2) Å , A mol = 56.30(1) Å 2 ).…”

Section: Non-solvated Assembliesmentioning

confidence: 99%

Scrolling of Supramolecular Lamellae in the Hierarchical Self-Assembly of Fibrous Gels

Jones

Kennedy

Walker

et al. 2017

Chem

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Gelation by small molecules is enormously topical in catalysis, nanomaterials, drug delivery, and pharmaceutical crystallization. The way in which gelators selforganize to give a 3D gel network is poorly understood. How does a system progress from a continuous pattern of supramolecular motifs to a network of fibers with well-defined morphologies? Why are gel fibers so homogeneous, and why do they form instead of crystals? This work shows, predictively, that gels arise by the scrolling of sheets with asymmetric surface structures.

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Section: Non-solvated Assembliesmentioning

confidence: 99%

Scrolling of Supramolecular Lamellae in the Hierarchical Self-Assembly of Fibrous Gels

Jones

Kennedy

Walker

et al. 2017

Chem

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“…Crystallization of naphthalene 5 under several conditions afforded similar molecular conformations but several types of assemblies. The bowl shaped naphthalenes arranged the ureas in parallel, a unit that assembled into extended columns (1 mg mL –1 in DMSO/H 2 O, Figure c) or into lamellar structures (1 mg mL –1 in MeOH/H 2 O) . The columns have interpenetrating water molecules and DMSO molecules that form hydrogen bonds with the ureas in lieu of the urea self-association.…”

Section: Designmentioning

confidence: 99%

“…The bowl shaped naphthalenes arranged the ureas in parallel, a unit that assembled into extended columns (1 mg mL −1 in DMSO/H 2 O, Figure 5c) or into lamellar structures (1 mg mL −1 in MeOH/H 2 O). 39 The columns have interpenetrating water molecules and DMSO molecules that form hydrogen bonds with the ureas in lieu of the urea self-association. These examples illustrated how the information needed to specify columnar assembly has been lost and reinforced the importance of the original design parameters.…”

Section: Columnar Assembly By Crystallizationmentioning

confidence: 99%

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Functional Materials from Self-Assembled Bis-urea Macrocycles

2014

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CONSPECTUS: This Account highlights the work from our laboratories on bis-urea macrocycles constructed from two C-shaped spacers and two urea groups. These simple molecular units assembled with high fidelity into columnar structures guided by the three-centered urea hydrogen bonding motif and aryl stacking interactions. Individual columns are aligned and closely packed together to afford functional and homogeneous microporous crystals. This approach allows for precise and rational control over the dimensions of the columnar structure simply by changing the small molecular unit. When the macrocyclic unit lacks a cavity, columnar assembly gives strong pillars. Strong pillars with external functional groups such as basic lone pairs can expand like clays to accept guests between the pillars. Macrocycles that contain sizable interior cavities assemble into porous molecular crystals with aligned, well-defined columnar pores that are accessible to gases and guests. Herein, we examine the optimal design of the macrocyclic unit that leads to columnar assembly in high fidelity and probe the feasibility of incorporating a second functional group within the macrocycles. The porous molecular crystals prepared through the self-assembly of bis-urea macrocycles display surface areas similar to zeolites but lower than MOFs. Their simple one-dimensional channels are well-suited for studying binding, investigating transport, diffusion and exchange, and monitoring the effects of encapsulation on reaction mechanism and product distribution. Guests that complement the size, shape, and polarity of the channels can be absorbed into these porous crystals with repeatable stoichiometry to form solid host-guest complexes. Heating or extraction with an organic solvent enables desorption or removal of the guest and subsequent recovery of the solid host. Further, these porous crystals can be used as containers for the selective [2 + 2] cycloadditions of small enones such as 2-cyclohexenone or 3-methyl-cyclopentenone, while larger hosts bind and facilitate the photodimerization of coumarin. When the host framework incorporates benzophenone, a triplet sensitizer, UV-irradiation in the presence of oxygen efficiently generates singlet oxygen. Complexes of this host were employed to influence the selectivity of photooxidations of 2-methyl-2-butene and cumene with singlet oxygen. Small systematic changes in the channel and bound reactants should enable systematic evaluation of the effects of channel dimensions, guest dimensions, and channel-guest interactions on the processes of absorption, diffusion, and reaction of guests within these nanochannels. Such studies could help in the development of new materials for separations, gas storage, and catalysis.

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“…2011 年, Shimizu 课题组 [11] 报道了利用 1,3 图式 1 含双脲基团的大环化合物 1 的合成及其催化反应 Scheme 1 Synthesis of the macrocycle 1 with bis-urea groups and its catalytic reaction 图式 2 含双脲基团的大环化合物 2 的合成 Scheme 2 Synthesis of the macrocycle 2 with bis-urea groups 为了进一步探究结构单元与此类双脲大环分子的结构之间的关系, Shimizu 课题组 [13] 报道了基于萘环构建的双脲大环分子 3. 与基于苯环(吡啶环)构建的双脲分子不同的是, 萘环之间呈现出一种独特的平行碗状结构, 并且在不同的溶剂体系中得到两种不同的晶型 (Scheme 3).…”

Section: 基于(硫)脲键构筑的大环化合物unclassified

Recent Progress on the Construction and Function of Macrocyclic Compounds Containing Hydrogen Bond Donors

Huang¹,

Chen²,

Wei³

et al. 2020

Chin. J. Org. Chem.

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Because of the N-H group structure in the macrocyclic compound containing hydrogen bond Donors, it can provide additional intermolecular forces in the host-guest chemistry, and this character is widely used in the molecular recognition, self-assembly, supramolecular catalysis and other fields. The recent progress on the synthetic methods of macrocyclic compounds based on (thio) urea, amide and its molecular recognition in 2010～2019 are summarized. It is hoped that this review can be referred to synthesis and applications of this kind of macrocyclic compounds.

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A bis-urea naphthalene macrocycle displaying two crystal structures with parallel ureas

Cited by 4 publications

References 24 publications

Scrolling of Supramolecular Lamellae in the Hierarchical Self-Assembly of Fibrous Gels

Scrolling of Supramolecular Lamellae in the Hierarchical Self-Assembly of Fibrous Gels

Functional Materials from Self-Assembled Bis-urea Macrocycles

Recent Progress on the Construction and Function of Macrocyclic Compounds Containing Hydrogen Bond Donors

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