Igor A. Baburin

Interpenetrated three-dimensional hydrogen-bonded networks from metal–organic molecular and one- or two-dimensional polymeric motifs

The occurrence of interpenetrated three-dimensional networks has been systematically investigated by the analysis of the crystallographic structural databases, using the program package TOPOS. After our previous reports on interpenetration observed in valence-bonded MOFs, inorganic arrays and hydrogen-bonded organic supramolecular architectures, in this paper we have focused our research on the interpenetrated 3D networks based on hydrogen-bonded metal–organic molecular (0D) and polymeric (1D and 2D) complexes from the Cambridge Structural Database. The current interest for the crystal engineering of new functional materials has prompted many research groups to adopt synthetic strategies implying the use of molecular metal complexes (0D) with suitably exo-oriented hydrogen-bond donor and acceptor groups for the assembly of extended networks. With regard to this we have examined 3D hydrogen-bonded supramolecular arrays formed by finite and infinite motifs of lower dimensionality, analyzing their topologies and looking for their entanglements. We have extracted a comprehensive list including 135 different motifs (71 assembled from 0D, 43 from 1D and 21 from 2D metal–organic motifs) showing the phenomenon of interpenetration (about two thirds not detected in the original papers). These hydrogen-bonded networks include species assembled by one or more building blocks, that are classified within the previously introduced Classes of interpenetration. It is observed that the maximum interpenetration degree is limited to 5-fold and the main (overall) topology is 412.63-pcu. An analysis of the possible relationships between the dimensionality of the building blocks and the resulting network connectivity and topology, and of some factors determining the interpenetration is also attempted, together with a comparison of the present results with those for other families of interpenetrated materials.

Enumeration of Not-Yet-Synthesized Zeolitic Zinc Imidazolate MOF Networks: A Topological and DFT Approach

Twenty-one zeolitic imidazolate metal-organic frameworks based on Zn connectors (ZIFs) are derived and compared to known imidazolate networks. Not-yet-synthesized zinc imidazolates are identified on the basis of DFT total energy scoring. The structure with lowest energy is not porous and represents an unusual structure type with zni topology. Total energy scoring indicates the lcs and pcb networks as reliable ZIF candidates. The intrinsic channel chirality of the lcs network makes this rare topology an attractive target for the synthetic effort. Among the porous ZIFs candidates, the sodalite type, sod, is also found.

Dye Encapsulation Inside a New Mesoporous Metal–Organic Framework for Multifunctional Solvatochromic‐Response Function

Metal–organic frameworks (MOFs), hybrid materials built up from metal clusters and organic linkers, have shown a huge potential for a wide range of applications. In recent years, MOFs have set new records in terms of specific surface areas and pore volumes and therefore are highly suitable as storage materials for small and large molecules. The development of new materials is crucial for the improvement of storage devices, but MOFs are also ideal candidates for functionalization. One functionalization strategy is the integration of complex organic linker molecules containing secondary functional groups. However, this approach is synthetically demanding and not general, because functional donor atoms may affect the linker connectivity resulting in unexpected network topologies. A second powerful strategy is postsynthetic modification of the framework. In this case, the range of functions is restricted due to the limited stability of MOFs against aggressive chemicals. A modular and more versatile approach may be the encapsulation of functional guest molecules into the MOF material. However, for these systems leaching is critical. A crucial requirement in all cases is also the accessibility of MOF functionalities for guest molecules. In this context, a large pore size is highly beneficial. However, the development of such mesoporous frameworks is challenging, because expanded frameworks are often more fragile leading to a collapse of the framework during removal of included guests molecules. A very effective concept to achieve robust frameworks lies in the creation of hierarchical pore structures by combination of two different linker molecules. The most prominent examples of such copolymerization approach are UMCM-1/ 2/ 3, DUT-6 and DUT-23 or MOF210. In the case of DUT-23, auxiliary linker was used successfully to avoid interpenetration and to enhance the robustness, which resulted in highly porous structures. To date, this concept was restricted only to the combination of triand ditopic linkers. On the other hand, DUT-10(M) (M= Zn, Cu, Co) compounds based on the tetratopic N,N,N’,N’benzidinetetrabenzoate (benztb) ligand and the paddlewheel secondary building unit (SBU) undergo structural change upon solvent removal. By enhancing the connectivity of the framework by using a six-connecting [Zn4O] 6+

Packings of Carbon Nanotubes – New Materials for Hydrogen Storage

Packings of carbon nanotubes with three and four different orientations of tube axes (one of such structures is displayed in the figure) are shown to be energetically and mechanically stable systems with outstanding hydrogen storage properties (total uptake amounts up to 19.0 wt% at 77 K and 5.5 wt% at 300 K) approaching the Department of Energy targets.

Superhard s p3 carbon allotropes with odd and even ring topologies

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Three-dimensional hydrogen-bonded frameworks in organic crystals: a topological study.

s{p}^{3}

Graphene-based technologies for energy applications, challenges and perspectives

carbon allotropes with six, eight, and 16 atoms per primitive cell have been derived using a combination of metadynamics simulations and topological scan. A chiral orthorhombic phase

Hydrogen storage in high surface area graphene scaffolds

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A rare alb-4,8-Cmce metal–coordination network based on tetrazolate and phosphonate functionalized 1,3,5,7-tetraphenyladamantane

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Zeolitic imidazolate framework-71 nanocrystals and a novel SOD-type polymorph: solution mediated phase transformations, phase selection via coordination modulation and a density functional theory derived energy landscape

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