Nano- and micro-composites comprised of porous carbon and magnetic particles are prepared by one-step pyrolysis of metal-organic frameworks (MOFs). The porosity and composition of resulting magnetic porous carbons are facilely regulated by altering the pyrolysis temperature and changing the organic building blocks incorporated within the initial MOFs.

Heterogeneous solid sensors are regarded as promising next-generation sensor due to their excellent chemical stability, low contamination and excellent recyclability, despite their low sensitivity and weak signal. The dispersity and signals specifically from the exterior of solid sensors are critical aspects which define the sensing sensitivity and selectivity. A novel strategy for the preparation of ideal heterogeneous sensors based upon luminescent lanthanide coordination polymers (LnCP) has been demonstrated. Ideal heterogeneous sensors are systematically achieved by producing the sensors in small, uniform and thin core-shell particles (silica@LnCP, Ln = Eu, Tb). Eventually, we found that the extremely small amount of well-structured silica@LnCP microsphere, less than ca. 1/400 compared to the amount of several known coordination polymer-based sensors, was sufficient to achieve a reliable Cu2+ sensing with even much greater sensitivity (ca. 550% improvement).

Microsized chemosensor particle (CPP-16, CPP means coordination polymer particle), which is made from a metal-organic framework (MOF), is synthesized using pyrene-functionalized organic building block. This building block contains three important parts, a framework construction part, a Cu(2+) detection part, and a fluorophore part. PXRD studies have revealed that CPP-16 has a 3D cubic structure of MOF-5. During both MOF formation and sensing event, fluorophores within CPP-16 undergo dual changes in conformation and optical properties. After MOF construction, pyrene moieties experience an unusual complete conversion from monomer to excimer form. This conversion takes place due to a confinement effect induced by space limitations within the MOF structure. The selective sensing ability of CPP-16 on Cu(2+) over many other metal ions is verified by emission spectra and is also visually identified by fluorescence microscopy images. Specific interaction of Cu(2+) with binding sites within CPP-16 causes a second conformational change of the fluorophores, where they change from stacked excimer (CPP-16) to quenched excimer states (CPP-16·Cu(2+)).

A solvothermal approach based on In3+ and three organic linkers, 2,6-naphthalenedicarboxylic acid (H2NDC), 4,4′-biphenyldicarboxylic acid (H2BPDC) and 1,4-benzenedicarboxylic acid (H2BDC), for the synthesis of five types of coordination polymer particles (CPPs) has been demonstrated. Five CPPs are selectively fabricated in rod, lump, ribbon, sphere and sea urchin shapes depending on the organic linkers used in the reactions. The simultaneous incorporation of two different organic linkers within a CPP in a specific ratio was verified when CPPs are synthesized from a mixture of two organic linkers. The porosity and specific gas sorption properties of five CPPs are evaluated via gas sorption measurements on N2, CO2 and H2. Their porosity and specific gas sorption ability also vary depending on the linkers used in their fabrication process. While two CPPs synthesized using only one kind of organic linker are non-porous, three CPPs fabricated using the mixture of two different organic linkers are highly porous. Significant increases in the CO2 and H2 uptake abilities are also observed when CPPs are synthesized from two mixed linkers.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The ability to fabricate multicompositional hybrid materials in a precise and controlled manner is one of the primary goals of modern materials science research. In addition, an understanding of the phenomena associated with the systematic growth of one material on another can facilitate the evolution of multifunctional hybrid materials. Here, we demonstrate precise manipulation of the isotropic and/or anisotropic nanoscale growth of various coordination polymers (CPs) to obtain heterocompositional hybrid coordination polymer particles. Chemical composition analyses conducted at every growth step reveal the formation of accurately assembled hybrid nanoscale CPs, and microscopy images are used to examine the morphology of the particles and visualize the hybrid structures. The dissimilar growth behavior, that is, growth in an isotropic or anisotropic fashion, is found to be dependent on the size of the metal ions involved within the CPs.

Scheme 1 . Preparation of multi ball-in-ball hybrid metal oxides. Many examples of microand nanoscale particles made from atomic or molecular building blocks are known, with these systems having been extensively explored due to their useful properties. [ 1–6 ] Currently, efforts are ongoing to manipulate the composition, as well as its size and morphology, of particles as part of systematic attempts to alter their chemical and physical properties. Within this context, chemical transformation has emerged a useful method for tuning the composition. [ 7 , 8 ]

The conjunction of porous ZIF-8 with polystyrene spheres is demonstrated to induce the formation of polystyrene@ZIF-8 core-shell structures. A subsequent etching process on polystyrene@ZIF-8 core-shells to remove polystyrene cores results in a unique hollow ZIF-8.

Monodisperse hollow metal oxides are generated from silica@coordination polymer core/shell precursors through a calcination process to transform coordination polymers into metal oxides, followed by an etching process to remove silica cores. The layer thicknesses of the hollow structures are effectively controlled by adjusting the shell thicknesses of the coordination polymers within the silica@coordination polymer core/shell precursors.

A three-dimensional extended, metal-organic rotaxane framework (MORF) that incorporates encircled "struts" has been synthesized through a one-pot self-assembly process involving a macrocyclic tetraimidazolium "molecular box", naphthalene dicaboxylate dianion, and Zn(II) cations. The present system represents progress towards controlling the features of three-dimensional metal-organic frameworks.

A strategy for the synthesis of composition-tunable hybrid metal oxide particles with a unique ball-within-ball structure is reported on p. 1720 by Moonhyun Oh and co-workers. The systems were logically formulated using the following processes: 1) CPP preparation using a precipitation method, 2) cation exchange reaction for composition transformation of CPPs, and 3) a final calcination processing of prepared CPPs that engenders decomposition of the CPPs and formation of metal oxides.

Coordination polymer nanorods are synthesized from the hexagonal 3D structure of Fe-MIL-88B. Subsequently, hematite (α-Fe(2)O(3)) and magnetite (Fe(3)O(4)) nanorods are selectively prepared by controlling the calcination conditions of coordination polymer nanorods.

A facile, one-pot synthesis of rotaxanated supramolecular organic frameworks (RSOFs) is reported. These systems consist of bis-carboxylate anions threaded through the core of tetraimidazolium macrocycles. Trivalent metal cations, yttrium(III) and smaller lanthanides, are used to "lock" the threaded strut in place. This results in the formation of three-dimensional RSOFs.

Narrowly-dispersed fluorescent octahedron and rounded-octahedron coordination polymer particles (CPPs) have been synthesized from the solvothermal reaction of In(NO3)3·xH2O and 2,6-bis[(4-carboxyanilino)carbonyl]pyridine. The shape and size of the resulting CPPs were dependent on the amount of solvent (and thus the concentration of reactants) used in the reaction. Under poor solubility conditions with only a small amount of DMF, the formation of coordination polymers proceeds quickly and the particle growth commences at a large number of sites, thus resulting in smaller particles. By decreasing the amount of DMF used in the reaction from 800 μL to 400 and 200 μL, the average size of the resulting CPPs was reduced from 2.22 ± 0.40 μm to 834 ± 120 and 431 ± 36.9 nm, respectively. In addition, we have found that some additives such as bipyridine and acetic acid, even though they were not incorporated within CPPs, did play an important role in the formation of CPPs by means of manipulating the deprotonation rate of organic building blocks and so affect the size and morphology of the resulting CPPs. Fluorescent octahedron and rounded-octahedron CPPs with specific size ranging from 307 nm to 2.22 μm were successfully prepared. Control of the size and morphology of colloidal particles is one of our central aims, both in terms of fundamental interest and for practical applications. Therefore, this work should provide significant assistance in the development of CPP materials.

Multicomponent fluorescent hexapod coordination polymer particles (CPPs) have been synthesized from Zn2+ ions and two kinds of fluorescent building blocks (1,4-biphenyldicarboxylic acid, H2bpdc and N,N′-phenylenebis(salicyclideneimine)dicarboxylic acid, 1). The ultimate size of the final hexapod CPPs depended upon the size of the initially-formed cube CPPs, which acted as the template for growth of the secondary coordination polymers. SEM studies conducted at numerous stages of growth revealed the several interesting intermediates, which give exceptionally strong evidence for the seed-directed formation of the hexapod CPP. Two continuous processes, the initial formation of seed CPPs with a cubic shape and the growth of secondary CPs on the six facets of the cube seeds for the final formation of micro-sized hexapods, were monitored via microscopy. The analyses of the initial and final products also revealed that they had different chemical compositions and so different optical properties. In addition, zinc oxide particles with a maintained hexapod shape have been prepared from the simple calcination of hexapod CPPs.

In this work, mesoporous carbon nanofibers (MCNF) were synthesized by using a template of mesoporous silicate nanofibers within anodic aluminum oxide (AAO) film and furfuryl alcohol for the carbon source at the carbonization temperatures (600, 900, and 1200°C). Due to the easy control nature of pore size and thickness of AAO film, the diameter and length of MCNF can easily be controlled. The MCNF pyrolyzed at 1200°C shows the highest BET surface area. The surface area is discussed with the structural properties associated. Also, hydrogen uptake capacity of MCNF is measured to examine the nanofibers for the potential application as a hydrogen storage media. Among them, MCNF carbonized at 1200°C shows 0.73wt.% of the highest hydrogen uptake at 77K and 0.1MPa. Results of the study indicate that the capacity of the MCNF for hydrogen storage shall increase as the carbonization temperature increases. The structural property and the surface area of MCNFs depending on carbonization temperature were discussed with their hydrogen uptake efficiency.

AbstractHexagonale Röhren und Ringe mit ungewöhnlichen Formen wurden durch einen einzigartigen Autotemplatmechanismus erzeugt. Wie M. Oh und Mitarbeiter in der Zuschrift auf S. 1487 ff. beschreiben, wirken anfänglich gebildete Koordinationspolymerpartikel (CPPs) als Template für die wachsenden hexagonalen Röhren und Ringe. Einfaches Kalzinieren der CPPs führt zur spontanen Bildung von ZnO‐Partikeln, die die speziellen Formen der CPPs beibehalten.magnified image

Although the vast majority of coordinationpolymermaterials,includingmetal–organicframeworks(MOFs),are focused on macroscaled crystalline products, for structuralstudies based on single-crystal X-ray analysis, we and others haverecently reported the synthetic strategies for the preparation ofnano- and microsized coordination polymer particles (CPPs).

This template will self-destruct: A unique particle-growth mechanism involves growth of new coordination polymers on the surface of initially formed hexagonal blocks and concomitant dissolution of the blocks to form hexagonal tubes (see scheme and scanning electron, optical, and fluorescence microscopy images). Calcination of the tubes yields ZnO particles of the same shape.