Three cobalt-based coordination polymers with tripodal carboxylate and imidazole-containing ligands: syntheses, structures, properties and DFT studies

Abstract

The tripodal carboxylate ligand can be employed in Co(ii) salt/imidazole-containing ligand systems to generate 1D chain, 2D layer, and 2D to 3D network, and the fluorescence properties of 1–3 and magnetic behavior of 1 and 2 have been investigated.

Structural, Spectroscopic Characterization and Application of a Co(II) Coordination Polymer [Co(suc)(bpm)] ⋅ 2H2O

“…The plot of 1/χ M vs T showed linearity over the entire temperature range obeying the Curie‐Weiss law given as; χ M $${={{{\rm C}}\over{{\rm T}-{\rm \phi{} }}}}$$ where χ M is the magnetic susceptibility in cm 3 mol −1 , C is the Curie constant in cm 3 mol −1 K, T is the temperature in Kelvin and φ is the Weiss constant in Kelvin. A fitting of the Curie‐ Weiss law on the data gave Curie Constant (C)= 1.803 cm 3 mol −1 K obtained from inverse of the slope and a negative Weiss constant (φ)= −30.163 K, suggesting weak antiferromagnetic (AF) exchange interactions, evinced from declining χ M T values upon cooling with an effective magnetic moment of 3.8 BM using μ eff = (8 C) 1/2 [1,3,18,21,22,26–29,32,33] …”

“…A fitting of the Curie-Weiss law on the data gave Curie Constant (C) = 1.803 cm 3 mol À 1 K obtained from inverse of the slope and a negative Weiss constant (φ) = À 30.163 K, suggesting weak antiferromagnetic (AF) exchange interactions, evinced from declining χ M T values upon cooling with an effective magnetic moment of 3.8 BM using μ eff = (8 C) 1/2 . [1,3,18,21,22,[26][27][28][29]32,33]…”

Slow Magnetic Relaxation in {[CoCxAPy)] 2.15 H2O}n MOF Built from Ladder-Structured 2D Layers with Dimeric SMM Rungs

“…The local coordination in 1 is a distorted octahedron CoN 2 O 4 , with four oxygen atoms in the equatorial plane and two apical N atoms, which gives rise to a positive anisotropy constant D /k B = 82 K with an orthorhombic component E / D = 0.13. The most similar cases, from the viewpoint of the coordination and bridging paths are [Co(Htatb)(bimbp)].DMF, and [Co(Htatb)(1-3-bimbp)].DMF [ 54 ]. The three compounds have just 2 Co-O-C-O-Co syn-syn bridges, giving rise to an exchange interaction constant ranging between J /k B = −6.65 and −2.3 K, that is, a weak antiferromagnetic interaction.…”

A Co-Crystallised Cobalt(II) Cluster of Pyridinedicarboxylic Acid (PDC) as a Luminescent Material for Selective Sensing of Methanol

“…Compound 1, showed a similar emission at 437 nm (λex = 345 nm) but with much lower intensity which may be due to the partially filled d orbital of the Co 2+ (3d 7 ) ion leading to Ligand to Metal charge transfer (LMCT) [29,30]. The similarity in the emission wavelength of the free ligand and the title compound suggests that the luminescence of 1 is attributed to ligand-based emissions [31].…”