Strontium‐Carboxylate‐Based Coordination Polymers: Synthesis, Structure and Dielectric Properties

Impact of Host-Guest Interactions on the Dielectric Properties of MFM-300 Materials

Metal-organic framework (MOF) materials are attracting increasing interest in the field of electronics due to their structural diversity, intrinsic porosity, and designable host-guest interactions. Here, we report the dielectric properties of a series of robust materials, MFM-300(M) (M = Al, Sc, Cr, Fe, Ga, In), when exposed to different guest molecules. MFM-300(Fe) exhibits the most notable increase in dielectric constant to 35.3 ± 0.3 at 10 kHz upon adsorption of NH3. Structural analysis suggests that the electron delocalization induced by host-guest interactions between NH3 and the MOF host, as confirmed by neutron powder diffraction studies, leads to structural polarization, resulting in a high dielectric constant for NH3@MFM-300(Fe). This is further supported by ligand-to-metal charge-transfer transitions observed by solid-state UV/vis spectroscopy. The high detection sensitivity and stability to NH3 suggest that MFM-300(Fe) may act as a powerful dielectric-based sensor for NH3.

Synthesis, crystal structures, dielectric and magnetic properties of manganese sulfonyldibenzoates

Six coordination polymers based on Mn(ii) and V-shaped ligand were successfully isolated and their dielectric as well as magnetic behaviours were investigated. The paper also discusses the growth of solids in terms of supramolecular aggregation.

Studies on Magnetic and Dielectric Properties of Antiferromagnetically Coupled Dinuclear Cu(II) in a One-Dimensional Cu(II) Coordination Polymer

A one-dimensional Cu(II) coordination polymer with encapsulated antiferromagnetically coupled binuclear Cu(II) has been synthesized by using 5-nitroisophthalic acid (5-N-IPA) and 4-aminopyridine (4-APY) [Cu₂(5-N-IPA)₂(4-APY)₄] _n (1). Electrical properties are examined by complex impedance (Z*), dielectric permittivity (ε*), and ac conductivity studies at different frequencies (10 kHz-5 MHz) and temperatures (253-333 K). The contribution of grain and grain boundary has been explained by a different theoretical model. The variable temperature magnetic susceptibility data for compound 1 were recorded between 300 and 2 K. The shape of the curve (χ_M T vs T) indicates dominant antiferromagnetic coupling, which results from the interaction between the copper(II) atoms.