Ferroelectricity is essential to many forms of current technology, ranging from sensors and actuators to optical or memory devices. In this circumstance, organic ferroelectrics are of particular importance because of their potential application in tomorrow's organic devices, and several pure organic ferroelectrics have been recently developed. However, some problems, such as current leakage and/or low working frequencies, make their application prospects especially for ferroelectric memory (FeRAM) not clear. Here, we describe the molecule-displacive ferroelectricity of supramolecular adducts of tartaric acid and 1,4-diazabicyclo[2.2.2]octane N,N′-dioxide. The adducts show large spontaneous polarization, high rectangularity of the ferroelectric hysteresis loops even at high operation frequency (10 kHz), and high performance in polarization switching up to 1 × 106 times without showing fatigue. It opens great perspectives in terms of applications, especially in organic FeRAM.

The development of highly efficient CO2 separation materials is very important for environmental preservation and energy conservation. Crystalline porous coordination polymers (PCPs)/metal–organic frameworks are one of a number of promising types of porous materials for CO2 separation because of their controllable pore size, shape and surface function. Simultaneously, the unique structural flexibility of PCPs affords both high CO2 selectivity and inexpensive regeneration. However, this family of materials suffers from the coexistence of water that destroys the framework of PCPs and its adsorption in the pores is greater than that of CO2, which results in a deterioration in CO2‐separation performance. Herein, a flexible and hydrophobic CuII PCP that is stable towards water has been designed and synthesised. This PCP has extremely high adsorption selectivity for CO2 over CH4, derived from its structural flexibility. Furthermore, the obtained water‐tolerant flexible PCP, under CO2/CH4 mixed‐gas conditions, exhibits highly selective CO2 adsorption over CH4, even in the presence of water.

A single crystal of (3-fluoro-4-methoxyanilinium)+([18]crown-6)[MnIICrIII(oxalate)3]−(CH3OH)2 had the space group Cc owing to the arrangement of the 3-fluoro-4-methoxyanilinium+ cation with C1 symmetry and, therefore, was pyroelectric. A ferromagnetic transition at 5.5 K was observed, which originated from the two-dimensional honeycomb structure of the [MnIICrIII(oxalate)3]− anion.

Coordination

Metal−organic network structure based on oxalate bridges {[Mn II Cr III (oxalate) 3 ] − } ∞ and supramolecular cations (H 2 PPD 2+ )(benzo[18]crown-6) 2 [MnCr(oxalate) 3 ]-(CH 3 OH)(CH 3 CN) 2 (1) and (o-FAni + ) 2 (DCH[18]crown-6) 2 [Mn(CH 3 OH)Cr(oxalate) 3 ][MnCr(oxalate) 3 ](CH 3 OH)(2), where H 2 PPD 2+ , o-FAni + , and DCH[18]crown-6 denote p-phenylenediammonium 2+ , o-fluoroanilinium + , and cis-syn-cisdicyclohexano[18]crown-6, respectively, were synthesized. The crystal structure of 1 was the combination of [Mn(Λ)-Cr(Λ)(oxalate) 3 ] − and [Mn(Λ)Cr(Δ)(oxalate) 3 ] − , whereas that of crystal 2 was the combination of [Mn(Λ)(CH 3 OH)-Cr(Δ)(oxalate) 3 ] and [Mn(Λ)Cr(Δ)(oxalate) 3 ]. Large flexible supramolecular cations provide the three-dimensional structure of {[Mn II Cr III (oxalate) 3 ] − } ∞ , which is different from the twodimensional honeycomb structure often observed for {[Mn II Cr III (oxalate) 3 ] − } ∞ complexes. Temperature-dependent magnetic susceptibilities of the complexes 1 and 2 exhibited ferromagnetic behaviors following the Curie−Weiss law (C = 11.5 cm 3 K mol −1 , θ = 13.0 K for 1; C = 4.14 cm 3 K mol −1 , θ = 12.3 K for 2).

A supramolecular cation of (m‐FAni+)(tst‐DCH[18]crown‐6), where m‐FAni+ and tst‐DCH[18]crown‐6 denote m‐fluoroanilinium and trans‐syn‐trans‐dicyclohexano[18]crown‐6, respectively, was introduced into a ferromagnetic {[MnIICrIII(oxalate)3]–} layer to obtain a stable organic‐inorganic hybridized crystal. The crystal structure of (m‐FAni+)(tst‐DCH[18]crown‐6){[MnIICrIII(oxalate)3]–} was constructed by alternate stacking of a two‐dimensional honeycomb layer of {[MnIICrIII(oxalate)3]–} and the supramolecular cations. Cyclohexyl moieties of tst‐DCH[18]crown‐6 penetrated the pores of the honeycomb layers, excluding solvent molecules in the crystal. The anionic layers showed ferromagnetic order of MnII and CrIII ions with S = 5/2 and S = 3/2 spins, respectively, at 5.5 K. Although the m‐FAni+ showed disorder with respect to 180° rotation of the aryl ring, no significant anomaly was observed in the dielectric response, suggesting that the disorder is static.

photoinduced SRG formation using a mixed film of DBAB-St and m-MTDATA has been investigated. ExperimentalDBAB-St was synthesized as follows: stearoyl chloride (0.70 g, 2.3 mmol) was added to a THF solution (20 mL) of 4-[4'-hydroxybiphenyl-4-yl(biphenyl-4-yl)amino]azobenzene (DBAB-OH: 1.0 g, 1.9 mmol), prepared by the procedure reported in our previous paper [ 23 ], and triethylamine (0.39 g, 3.9 mmol), and then the solution was stirred for 2 h at room temperature. After the solvent was removed under reduced pressure, the product was purified by silica-gel column chromatography using toluene as an eluent, followed by recrystallization from ethanol. Yield: 0.78 g (52%), m. Differential scanning calorimetry (DSC) was carried out by means of DSC6220 (Seiko Instruments Inc.) Photoinduced SRG formation was carried out by using a compact CW laser (488 nm: CYAN-488-100NH-W, Spectra Physics) as a source of writing beams. Atomic force microscopy (AFM) was performed by means of Scanning Probe Microscope (JSTM-4200D, JEOL Ltd.) with a micro cantilever (OMCL-AC160T-C2, Olympus). Results and discussionA novel photochromic amorphous molecular material, DBAB-St, was synthesized by the reaction of DBAB-OH with stearoyl chloride in the presence of triethylamine and identified by various spectroscopy and mass spectrometry (Scheme 1). DBAB-St was found to readily form an amorphous glass when the melt sample was cooled on standing in air.The Tg was determined to be 19 °C by DSC, which was considerably lower than that of the parent material, 4-[di(biphenyl-4-yl)amino]azobenzene (68 °C) [24]. The existence of the flexible long alkyl chain is assumed to reduce the Tg. The Tg of DBAB-St was found to be increased by mixing with m-MTDATA; the Tg of the mixed glass of DBAB-St and m-MTDATA with a ratio of 1:4 (w/w) was determined to be 48 °C.Using the amorphous films of DBAB-St and the mixed film of DBAB-St and m-MTDATA with a ratio of 1:4 (w/w), photoinduced SRG formation was investigated. The amorphous films were irradiated with two writing beams (488 nm) with incident angles of +10° and -10° with respect to the normal of the sample film and with polarization angles of +45° and -45° with respect to the p-polarization at 3 mW (ca. 95 mWcm -2 ) each (Fig. 1). J. Photopolym. Sci. Technol., Vol. 24, No. 5, 2011 528 Fig . 2 shows the growth of diffraction efficiency upon irradiation with writing beams at 20 °C.Whereas significant increase in diffraction efficiency could not be observed for the DBAB-St amorphous film upon irradiation with the writing beams, the diffraction efficiency gradually increased and reached to ca. 7% in 30 min for the mixed film of DBAB-St and m-MTDATA. In addition, SRG with a modulation depth of 170-190 nm was confirmed to be inscribed on the mixed amorphous film by means of AFM as shown in Fig. 3. Thus, the mixing with m-MTDATA drastically enhanced the SRGforming ability of DBAB-St.As discussed in our previous paper [13], the increasing Tg of the material prevents the collapse of the SRG due to surface tension to...

The cover picture shows a copper(II) porous coordination polymer that can adsorb CO2 over CH4 at high selectivity under CO2/CH4 mixed gas conditions, and even in the coexistence of water. Flexibility and hydrophobicity of the coordination polymer are key factors to achieving high separation efficiency and high water tolerance. More details can be found in the Full Paper by Shin‐ichiro Noro, Takayoshi Nakamura, and co‐workers on page 1517 in Issue 10, 2015 (DOI: 10.1002/cplu.201500278).