Metal-organic frameworks (MOFs) have received much attention because of their attractive properties. They show great potential applications in many fields. An emerging trend in MOF research is hybridization with flexible materials, which is the subject of this review. Polymers possess a variety of unique attributes, such as softness, thermal and chemical stability, and optoelectrical properties that can be integrated with MOFs to make hybrids with sophisticated architectures. Hybridization of MOFs and polymers is producing new and versatile materials that exhibit peculiar properties hard to realize with the individual components. This review article focuses on the methodology for hybridization of MOFs and polymers, as well as the intriguing functions of hybrid materials.

A series of conductive porous composites were obtained by the polymerization of 3,4-ethylenedioxythiophene (EDOT) in the cavities of MIL-101(Cr). By controlling the amount of EDOT loaded into the host framework, it was possible to modulate the conductivity as well as the porosity of the composite. This approach yields materials with a reasonable electronic conductivity (1.1 × 10(-3) S·cm(-1)) while maintaining high porosity (SBET = 803 m(2)/g). This serves as a promising strategy for obtaining highly nanotextured conductive polymers with very high accessibility for small gas molecules, which are beneficial to the fabrication of a chemiresistive sensor for the detection of NO2.

Porous titanium oxide materials are attractive for energy-related applications. However, many suffer from poor stability and crystallinity. Here we present a robust nanoporous metal–organic framework (MOF), comprising a Ti12O15 oxocluster and a tetracarboxylate ligand, achieved through a scalable synthesis. This material undergoes an unusual irreversible thermally induced phase transformation that generates a highly crystalline porous product with an infinite inorganic moiety of a very high condensation degree. Preliminary photophysical experiments indicate that the product after phase transformation exhibits photoconductive behavior, highlighting the impact of inorganic unit dimensionality on the alteration of physical properties. Introduction of a conductive polymer into its pores leads to a significant increase of the charge separation lifetime under irradiation. Additionally, the inorganic unit of this Ti-MOF can be easily modified via doping with other metal elements. The combined advantages of this compound make it a promising functional scaffold for practical applications.

of well-considered materials designs. [5] Small structural differences in component molecules are often capable of producing materials with totally different properties through organic syntheses, [6] supramolecular chemistry, [7] and materials processing. [8] Therefore, molecular designs for materials production can be regarded as the most important issue in science and technology in current society. Amongst the many possibilities in molecular design for materials production, exploration of molecular functions and material properties on the basis of chirality controls would be a scientifically elegant approach. With identical elemental compositions and functional groups, but different configurations of these identical groups, functions such as chiroptical properties and chiral separations can be created. [9] Another important fact for chiral controls in molecular and materials science is the unavoidable deep relationship of chiral substances with biological activities. [10] Biomolecules are basically made of chiral components such as amino acids and saccharides. Therefore, molecular designs for biomedical drugs and bioactive materials must be produced upon critical control of their chirality. Due to the scientifically elegant approaches and biological importance, molecular sciences and materials technologies incorporating chirality continuously attract attention of scientists ranging from the fundamentals of the chirality of molecules and materials to bio-related applications. These research efforts spread into a wide range of scientific fields including basic physical chemistry, [11] chirality-controlled catalysis and synthesis, [12] chiral materials, [13] analyses of chiral structures, [14] chiral recognition, [15] chiral separation, [16] chiral plasmons and optics, [17] chiral drugs, [18] and biomedical related chiral sciences. [19] Among the broad interests of chirality research, the recent hot trends of chirality related sciences are probably studies on chirality-based supramolecular chemistry and materials science upon the self-assembly of chiral molecular components [20] and achiral building blocks. [21] Enhancement of chiral effects and the creation of chirality are sometimes results of supramolecular organizations with chiral molecular units and even with achiral components. These systems are regarded as elegant examples of the emerging concept of nanoarchitectonics (Figure 1), [22] because control of simple molecular configurations can lead to the creation of such a wide variety of functional materials. The nanoarchitectonics concept was originally proposed by Aono and co-workers [23] as methodology to create functional materials from nanosized components through the combined Exploration of molecular functions and material properties based on the control of chirality would be a scientifically elegant approach. Here, the fabrication and function of chiral-featured materials from both chiral and achiral components using a supramolecular nanoarchitectonics concept are discussed. The contents are classified...

Four isostructural coordination polymer crystals having different metal ions were synthesized and studied for ball milling-induced glass formation. Distinct glass formation was discussed from crystal structures. Doping of molecules for CP glass during the milling was demonstrated, and it resulted in tunable glass properties (Tg and Tc) and enhancement of anhydrous H+ conductivity.

This short review focuses on recent developments in polymerization reactions using metal-organic frameworks (MOFs). MOFs are crystalline porous materials that are able to tune their frameworks, enabling their use as promising media for polymerization. The precise design of the MOF structure is key to controlling polymerizations, allowing for the regulation of not only primary but also higher-order structures.

Understanding the intrinsic properties of single conducting polymer chains is of interest, largely for their applications in molecular devices. In this study, we report the accommodation of single polysilane chains with hole-transporting ability in porous coordination polymers (PCPs), [Al(OH)(L)]n (1a; L = 2,6-naphthalenedicarboxylate, channel size = 8.5 × 8.5 Å(2), 1b; L = 4,4'-biphenyldicarboxylate, channel size = 11.1 × 11.1 Å(2)). Interestingly, the isolation of single polysilane chains increased the values of carrier mobility in comparison with that in the bulk state due to the elimination of the slow interchain hole hopping. Moreover, even when the chains are isolated one another, the main chain conformation of polysilane could be controlled by changing the pore environment of PCPs, as evidenced by Raman spectroscopy, solid-state NMR measurements, and molecular dynamics simulation. Hence, we succeeded in varying the conducting property of single polysilane chains. Additionally, polysilanes have a drawback, photodegradation under ultraviolet light, which should be overcome for the application of polysilanes. It is noteworthy that the accommodation of polysilane in the nanopores did not exhibit photodegradation. These results highlight that PCP-polysilane hybrids are promising candidates for further use in the field of molecular electronics.

Separation of high-molecular-weight polymers differing just by one monomeric unit remains a challenging task. Here, we describe a protocol using metal-organic frameworks (MOFs) for the efficient separation and purification of mixtures of polymers that differ only by their terminal groups. In this process, polymer chains are inserted by threading one of their extremities through a series of MOF nanowindows. Selected termini can be adjusted by tuning the MOF structure, and the insertion methodology. Accordingly, MOFs with permanently opened pores allow for the complete separation of poly(ethylene glycol) (PEG) based on steric hindrance of the terminal groups. Excellent separation is achieved, even for high molecular weights (20 kDa). Furthermore, the dynamic character of a flexible MOF is used to separate PEG mixtures with very similar terminal moieties, such as OH, OMe, and OEt, as the slight difference of polarity in these groups significantly changes the pore opening kinetics.