Complex of Tris(Phenanthroline)Cobalt(II)Trifluoroacetate: Characterisation and Powder XRD Analysis

Abstract

The powder complex of tris(phenanthroline)cobalt(II) trifluoroacetate (TFA) has been prepared by interaction of cobalt(II) nitrate, phenanthroline (phen) in aqueous solution with drops of ethanol, and an excess of saturated aqueous solution of sodium trifluoroacetate, whereupon the yellowish powder was produced. AAS measurment for the metal content, equivalent conductance (1:2), and TGA-DTA of the powder suggest the corresponding formula of [Co(phen)3](TFA)2.5H2O. The efffective magnetic moment of 4.9 BM indicates the high-spin nature of this complex which corresponds to three unpaired electrons in the electronic configuration of Co(II) with significantly higher than the spin only value due to the orbital contribution. UV-Vis spectrum of the complex reveals the d-d spin-allowed transition bands as well as the MLCT and intraligand band. The estimating transition energy ratio of 2.04 for ν2/ν1, is clearly in the range for octahedral configuration. The infrared spectral property indicates the main mode of vibrations for the functional groups of ligand phen and TFA, and thus supports strongly the formula proposed for this complex. The corresponding powder XRD was then refined using Rietica-Le Bail method and found to be fit as triclinic crystal system with space group of PĪ.

A Water‐Rich Cobalt(II) Compound: Hydrothermal Synthesis, Spectroscopic, Thermal, Crystal Structure Characterization and Antimicrobial Properties

“…On the other hand, the reduction process is represented by the cathodic peak current ( I pc ) which displays a cathodic potential peak ( E pc ) at 0.086 V vs Ag/AgCl electrode attributed to the reverse step. The potential peak difference (Δ E ) was calculated to be 0.059 V with an E 1/2 =0.056 V. The redox potential ( E o ) for the Co 2+ /Co 3+ couple was 0.137 V vs Ag/AgCl electrode which is in good agreement with the reported values of similar Co(II) compounds [60–62] . The CV plots of 1 were recorded at different scan rates (mV s −1 ) in water containing 0.1 M KCl as the supporting electrolyte vs Ag/AgCl (sat.…”

“…The FC-ZFC curves displayed an appreciable extent of bifurcation, higher χ M values for FC measurements may be attributed to the spin alignment of the unpaired electrons with respect to the applied field (100 Oe) while in the case of ZFC, the lower observed χ M values may be furnished to the randomization of the unpaired electron spins in the absence of an applied field. [54][55][56][57][58][59][60] Hence, the plot of variation of χ M T with temperature revealed a typical paramagnetic behaviour (Figure 2b), which lies in accordance with the single crystal data discussed in the later section on crystallographic analysis (vide infra). The effective magnetic moment (μ eff ) at room temperature (298 K) was calculated from χ M vs T plot and was found to be ∼ 3.98 BM.…”

“…The slight increase observed in the value of μ B could be due to the presence of minimal orbital angular momentum which is commonly perceived in Co(II) compounds. [59,60] Cyclic voltammetry (CV) was used to understand the redox behavior of high spin cobalt(II) complex. The CV plot of 1 is shown in Figure 3.…”

“…The potential peak difference (ΔE) was calculated to be 0.059 V with an E 1/2 = 0.056 V. The redox potential (E o ) for the Co 2 + / Co 3 + couple was 0.137 V vs Ag/AgCl electrode which is in good agreement with the reported values of similar Co(II) compounds. [60][61][62] The CV plots of 1 were recorded at different scan rates (mV s À 1 ) in water containing 0.1 M KCl as the supporting electrolyte vs Ag/AgCl (sat. KCl) reference electrode.…”

Preparation, Electronic Properties, and Powder-XRD Structure Analysis of 3,5-Bis(pyridin-2-yl)-H-1,2,4-triazoledichloridocopper(II)

“…However, it has been applied to that of iron(II) complex [28] quite recently and found to be a significant result. Since then, referring to the suggestion by Toby as well [29], application of this method has been extensively performed to some powdered complexes [30][31][32][33][34][35][36][37][38] and the results were found to be reasonably acceptable.…”