A two-dimensional organic-inorganic lead iodide perovskite: poly[bis(3-fluorocyclobutylammonium) [di-µ-iodido-diiodidoplumbate(VI)]].

In recent years, great technological advances have been achieved in the growth of hybrid organic-inorganic perovskites (HOIPs) and these have attracted extensive attention due to their optoelectronic properties, structural tunability and stability. We present here a new two-dimensional hybrid organic-inorganic perovskite, namely, poly[bis(3-fluorocyclobutylammonium) [di-µ-iodido-diiodidoplumbate(VI)]], {(C4H9FN)2[PbI4]}n, showing a two-dimensional reticular layer with the organic cations in the middle of the meshes. The calculated experimental band gap is 2.44 eV and the band gap is calculated as 2.20 eV theoretically, which further suggests the potential of this compound as a semiconductor.

Self-assembled metallogels formed from N,N',N''-tris(4-pyridyl)trimesic amide in aqueous solution induced by Fe(III)/Fe(II) ions.

In this work, we report self-assembled metallogels formed from a ligand of trimesic amide, N,N',N''-tris(4-pyridyl)trimesic amide (TPTA), induced by Fe(III)/Fe(II) ions. TPTA is difficult to dissolve in water even in the presence of some metal ions such as Cu(2+), Co(2+), Ni(2+), K(+), Na(+) and Mg(2+) under heating, and it exhibits no gelation ability. Interestingly, upon heating TPTA can be dissolved easily in aqueous solution containing Fe(3+)/Fe(2+), and subsequently self-assembled into metallogels after cooling. The metallogels could also be formed in aqueous solutions of mixed metal ions containing Fe(3+)/Fe(2+), indicating that the other metal ions do not affect the formation of Fe(III)-TPTA and Fe(II)-TPTA metallogels. The high selectivity of metallogel formation to Fe(3+)/Fe(2+) may be used for application in the test of Fe(3+)/Fe(2+). The metallogels obtained are characterized by scanning electron microscopy, Fourier transform infrared spectra, nuclear magnetic resonance spectra, rheological measurements and scanning tunneling microscopy. The results indicate that TPTA can self-assemble into fibrous aggregates in Fe(3+)/Fe(2+) aqueous solution through the metal-ligand interactions and intermolecular hydrogen bonding. This kind of metallogel also possesses good mechanical properties and thermoreversibility.

Uncovering the Role of Metal Catalysis in Tetrazole Formation by an In Situ Cycloaddition Reaction: An Experimental Approach.

Using an experimental approach, the role of metal catalysis has been investigated in the in situ cycloaddition reaction of nitrile with azide to form tetrazoles. It has been shown that metal catalysis serves to activate the cyano group in the nitrile reagent by a coordinative interaction.

Heat-set gels formed from easily accessible gelators of a succinamic acid derivative (SAD) and a primary alkyl amine (R-NH2).

Currently, the design and construction of an intelligent stimuli-responsive gel system is still a significant challenge. We present here a new gel system from which the formation of heat-set gels, conventional gels and irreversible heat-set gels can be achieved in aromatic solvents. This gel system is based on two-component gelators containing a succinamic acid derivative (SAD) and a primary alkyl amine (R-NH2). With the increase of temperature to 85 °C, a rarely reported reversible heat-set gel (gel formation with the increase of temperature) is afforded. Upon addition of fatty acids into two-component gelators, a conventional gel (gel formation with the decrease of temperature) is formed. When the fatty acid is replaced with dicarboxylic acid, a new heat-set gel is generated, which is irreversible and thermally super-stable. X-ray diffraction analysis reveals that the formation of a reversible heat-set gel relies on electrostatic interactions, hydrogen bonds, and hydrophobic interactions. These two-component gelators show a perfect gel system for the formation of diverse gels including heat-set gels, conventional gels and irreversible heat-set gels. The tunable strategy demonstrated in this letter may provide a new way for creation of more functional gels in gel science.

A two-dimensional copper(II) coordination polymer based on 2-propyl-1H-imidazole-4,5-dicarboxylic acid.

Single-crystal X-ray diffraction analysis of poly[bis(µ2-5-carboxy-2-propyl-1H-imidazole-4-carboxylato-κ(3)N(3),O(4):O(5))copper(II)], [Cu(C8H9N2O4)2)]n, indicates that one carboxylic acid group of the 2-propyl-1H-imidazole-4,5-dicarboxylic acid (H3PDI) ligand is deprotonated. The resulting H2PDI(-) anion, acting as a bridge, connects the Cu(II) cations to form a two-dimensional (4,4)-connected layer. Adjacent layers are further linked through interlayer hydrogen-bond interactions, resulting in a three-dimensional supramolecular structure.

A rare (3,4,5)-connected metal-organic framework featuring an unprecedented 1D + 2D → 3D self-interpenetrated array and an O-atom lined pore surface: structure and controlled drug release.

A rare (3,4,5)-connected self-interpenetrated metal-organic framework with an O-atom lined pore surface has been constructed from Zn(II) and H4L (H4L = 5,5'-(1,3,6,8-tetraoxobenzo[lmn][3,8]phenanthroline-2,7(1H,3H,6H,8H)diyl)-diisophthalic acid), which features an unprecedented 1D + 2D → 3D self-interpenetrated array and shows good controlled drug release properties.

A microporous hydrogen-bonded organic framework: exceptional stability and highly selective adsorption of gas and liquid.

An extremely stable hydrogen-bonded organic framework, HOF-8, was fabricated. HOF-8 is not only thermally stable but also stable in water and common organic solvents. More interestingly, desolvated HOF-8 exhibits high CO2 adsorption as well as highly selective CO2 and C6H6 adsorption at ambient temperature.