Functional Groups Assisted Tunable Dielectric Permittivity of Guest-Free Zn-Based Coordination Polymers for Gate Dielectrics.

The dielectric properties of coordination polymers has been a topic of recent interest, but the role of different functional groups on the dielectric properties of these polymers has not yet been fully addressed. Herein, the effects of electron-donating (R=NH ) and electron-withdrawing (R=NO ) groups on the dielectric behavior of such materials were investigated for two thermally stable and guest-free Zn-based coordination polymers, [Zn(L )(L )] (1) and [Zn(L )(L )] (2) [L =2-(2-pyridyl) benzimidazole (Pbim), L =5-aminoisophthalate (Aip), and L =5-nitroisophthalate (Nip)]. The results of dielectric studies of 1 revealed that it possesses a high dielectric constant (κ=65.

Regimented Charge Transport Phenomena in Semiconductive Self-Assembled Rhenium Nanotubes.

Photoconductivity, a crucial property, determines the potential of semiconductor materials for use in optoelectronic and photocatalytic device applications. The one-dimensional metal-organic nanotube semiconducting material [{Re(CO)}(bho)(phpy)] (MBT , where bho is benzene-1,2,3,4,5,6-hexaoate and phpy is 4-phenylpyridine) reported herein exhibits record photocurrent responses at a broad spectral range. MBT is comprised of a unique nanotube structure that is composed of six rhenium sites, six 4-phenylpyridine ligands, and a benzene-1,2,3,4,5,6-hexaoate unit.

Dielectric relaxation of the double perovskite oxide BaPrRuO.

Samples of BaPrRuO were prepared by the solid state reaction method and the structure was characterized by X-ray diffraction (XRD). Scanning electron microscopy (SEM) and dielectric measurements were performed in order to investigate the morphology and electric properties of the ceramics. X-ray diffraction data reveal that the BaPrRuO samples are of the cubic crystal structure with the space group 3̄ at room temperature.

High-κ Samarium-Based Metal-Organic Framework for Gate Dielectric Applications.

The self-assembly of a samarium-based metal-organic framework [Sm(bhc)(HO)] (1) in good yield was achieved by reacting Sm(NO)·6HO with benzenehexacarboxylic acid (bhc) in a mixture of HO-EtOH under hydrothermal conditions. A structural analysis showed that compound 1 crystallized in a space group of Pnmn and adopted a 3D structure with (4,8) connected nets. Temperature dependent dielectric measurements showed that compound 1 behaves as a high dielectric material with a high dielectric constant (κ = 45.

Semiconductor Behavior of a Three-Dimensional Strontium-Based Metal-Organic Framework.

The self-assembly of a three-dimensional strontium-based metal-organic framework [Sr(Hbtc)(H2O)]n (1) was achieved through the reaction of Sr(NO3)2 with a 1,2,4-benzenetricarboxylic acid (1,2,4-H3btc) ligand under hydrothermal conditions. This Sr-based metal-organic framework exhibits remarkable semiconducting behavior, as evidenced by theoretical calculations and experimental measurements. Temperature-dependent DC conductivity, near-room-temperature AC conductivity, diffuse reflection spectra, and photoluminescence spectra provide strong proof that compound 1 shows a band gap of 2.