Self‐Assembly of Cobalt(II) Coordination Polymers with Differently Halosubstituted Nicotinate Ligands and 4,4’‐Bipyridine – The Effect of the Halosubstituent Positions on Polymer Types

Abstract

Two structurally different 1D cobalt(II) coordination polymers with 4,4'-bipyridine (4,4'-bpy) and 2-chloronicotinate (2-Cl-nic) or 5-bromonicotinate (5-Br-nic), namely {[Co(2-Cl-nic) 2 (4,4'bpy)(H 2 O) 2 ] • 4H 2 O} n (1) and {[Co(4,4'-bpy)(H 2 O) 4 ] [Co(5-Brnic) 4 (H 2 O) 2 ] • 4,4'-bpy • 2H 2 O} n (2), were prepared under the same experimental conditions. The cobalt(II) ions in 1 are bridged by 4,4'-bipyridine ligands into a 1D polymeric chain, each cobalt(II) ion being coordinated with two O-monodentate 2-chloronicotinate ligands and two water molecules as well, while 2 consists of a complex cation {[Co(4,4'-bpy)(H 2 O) 4 ] 2 + } n , in which cobalt(II) ions are bridged by 4,4'-bipyridine ligands into a 1D polymeric chain, and a complex anion [Co(5-Br-nic) 4 (H 2 O) 2 ] 2À , in which cobalt(II) ion is coordinated with four 5-bromonicotinate ligands (two of them being O-monodentate and the other two are Nmonodentate) and two water molecules. DFT calculations revealed a correlation between the halosubstituent (chlorine or bromine) positions in the employed nicotinate ligands and the cobalt(II) coordination environments in the obtained coordination polymers, being responsible for their different structural types.

A series of nickel(ii) thiocyanate complexes comprising various molar contents of isonicotinamide and water as ligands or co-crystallized moieties – an experimental and computational study

“…Also, during geometry optimization we included the implicit SMD solvation with all parameters for pure water, in line with our earlier reports that used the same approach to interpret solid-state features of a variety of metal complexes. 36–38 As such, all reported values correspond to solution-phase Gibbs free energies at room temperature (298.15 K) and normal pressure (1 atm) and include both the electronic and the solvation components. Accordingly, the presented interaction energies (Δ G INT ) are calculated as a difference between the total Gibbs free energy of the complex and those from its components.…”

Electrochemical Properties and Perspectives of Nickel(II) and Cobalt(II) Coordination Polymers-Aspects and an Application in Electrocatalytic Oxidation of Methanol

“…The electrochemical properties and behaviour of coordination polymers have been neglected and poorly reported in the literature but have recently attracted increasing interest. Cyclic voltammetry is the most commonly used electrochemical technique for characterizing coordination polymers, offering information about the redox activity of metal ions and ligands [5,6], while also providing insight into the potential application of coordination polymers as suitable materials for sensor development [7][8][9][10][11][12][13][14].…”