Absorption spectra of cobalt(II) chloride and nitrate complexes in aqueous calcium nitrate–ammonium nitrate melts: The influence of solvent composition

Gadžurić, Slobodan; Zsigrai, István J.; Dožić, Sanja

doi:10.1016/j.molliq.2009.12.002

Cited by 15 publications

(13 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…10) 10 After 120 minutes of photodegradation in the NMR spectrum three new signals were identified, at 2.99, 2.73 and 2.56 ppm. The intensities of these signals were increased as degradation of the starting [HO(CH 2 ) 2 mim]NO 3 moiety progressed.…”

Section: Intermediates Of Photodegradationmentioning

confidence: 98%

“…55 By addition of small amounts of a molecular solvent in anhydrous molten salts in order to decrease the melting point, a large number of suitable media in which cobalt(II) halide complexes show thermochromic behaviour were obtained. [6][7][8] Studies have shown that cobalt(II) thermochromism strongly 60 depends on the amount of added molecular solvent as well as its physical and chemical properties, 9,10 but the reason why this effect occurs in these systems was not successfully explained. Also, it remained an open question whether thermochromic effect may occurs in systems that do not contain a molecular solvents, 65 but that remains liquid at temperatures that are low enough for possible application in practice.…”

Section: Introductionmentioning

confidence: 99%

“…in the mixture with inorganic salts significantly improves cobalt(II) 5 thermochromism. [8][9][10][11] Ionic liquids are the excellent solvent candidate due to their unique physical and chemical properties (e.g. negligible vapour pressure, low toxicity, non-corrosivity etc.)…”

Section: Introductionmentioning

confidence: 99%

“…negligible vapour pressure, low toxicity, non-corrosivity etc.) and thermochromic behaviour of chlorido nickel complexes was already investigated 10 in 1-hydroxylalkyl-3-methylimidazolium based ionic liquids. 12 In addition, it is possible to synthesize required ionic liquid with tunable properties in order to obtain the most suitable solvent.…”

Section: Introductionmentioning

confidence: 99%

“…3) are ascribed to complex formation. The complex formation in mixed ligand system is illustrated by a set of overall equilibrium: 10 Co…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Thermochromism, stability and thermodynamics of cobalt(ii) complexes in newly synthesized nitrate based ionic liquid and its photostability

et al. 2014

Self Cite

View full text Add to dashboard Cite

In this work a 1-(2-hydroxyethyl)-3-methylimidazolium nitrate ionic liquid, [HO(CH2)2mim]NO3, has been synthesized in order to serve as a new thermochromic material upon addition of cobalt(II) ions. Spectrophotometric measurements of a series of cobalt(II) nitrate and cobalt(II) chloride solutions in [HO(CH2)2mim]NO3 at 298.15, 308.15, 318.15, 328.15, and 338.15 K, were performed. Based on the recorded spectra, the overall stability constants and thermodynamic parameters for the cobalt(II) associations with chloride and nitrate ions were calculated. The thermodynamic calculations suggest that thermochromism is not observed in the ionic medium due to a small entropy change during the replacement of nitrate with chloride ions in the co-ordination sphere of cobalt(II). The absence of the molecular solvent was also the reason for the lack of thermochromism. Thus, cobalt(II) solutions in [HO(CH2)2mim]NO3 and water mixtures were studied as a new and green medium that can be used for the auto-regulation of the light intensity and shade protection. The investigated system with water upon addition of cobalt(II) was found to be a far more efficient and responsive thermochromic medium for all of the studied systems up until now. The structure of [HO(CH2)2mim]NO3 was confirmed by both (1)H NMR and IR spectroscopy. Also, the efficiency of different advanced oxidation processes (UV-induced photolysis, UV/H2O2 photolysis, heterogeneous photocatalysis using TiO2 Degussa P25 and TiO2 with 7.24%, w/w Fe catalysts) for [HO(CH2)2mim]NO3 degradation were investigated. The reaction intermediates formed during the photo-oxidation process were identified using LC-ESI-MS/MS and (1)H NMR techniques.

show abstract

Section: Intermediates Of Photodegradationmentioning

confidence: 98%