TY  - JOUR
AU  - Savović, Jelena
AU  - Nikolic, R
AU  - Veselinović, Dragan S.
PY  - 2004
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2788
AB  - The absorption spectra of Co(II) chloride complexes, containing variable concentrations of chloride ligand, in a molten mixture of 80 mol% acetamide-20 mol% calcium nitrate tetrahydrate, were studied at 313, 333, 353, and 363 K, in the wavelength range 400-800 nm. The melt contains three possible ligands (CH3CONH2, H2O, and NO3-) for competition with added chloride ligand. Addition of chloride caused a shift of the absorption maximum of octahedral cobalt( II) nitrate towards lower energies and pronounced changes in the shape of the initial spectrum of cobalt( II) nitrate. The effect of temperature changes on the molar absorption coefficient of the Co( II) species was dependent on the chloride concentration and was attributed to the structural changes occurring in the cobalt( II) species. The STAR and STAR FA programs were applied to identify the complex ionic species and to calculate the stability constants of Co( II) complexes formed in this solvent. The results indicate the highest probability of formation of the following complex species: Co(NO3)(4)(2-), Co(NO3)(2)Cl-2(2-), and CoCl42-. Stability constants of each complex were presented for the equilibria occurring at 313, 333, 353, and 363 K. Distribution of the Co( II) species was also calculated over the ranges of chloride concentration and temperature investigated.
T2  - Journal of Solution Chemistry
T1  - Cobalt(II) chloride complex formation in acetamide-calcium nitrate tetrahydrate melts
VL  - 33
IS  - 3
SP  - 287
EP  - 300
DO  - 10.1023/B:JOSL.0000035361.89473.a4
ER  - 

@article{
author = "Savović, Jelena and Nikolic, R and Veselinović, Dragan S.",
year = "2004",
abstract = "The absorption spectra of Co(II) chloride complexes, containing variable concentrations of chloride ligand, in a molten mixture of 80 mol% acetamide-20 mol% calcium nitrate tetrahydrate, were studied at 313, 333, 353, and 363 K, in the wavelength range 400-800 nm. The melt contains three possible ligands (CH3CONH2, H2O, and NO3-) for competition with added chloride ligand. Addition of chloride caused a shift of the absorption maximum of octahedral cobalt( II) nitrate towards lower energies and pronounced changes in the shape of the initial spectrum of cobalt( II) nitrate. The effect of temperature changes on the molar absorption coefficient of the Co( II) species was dependent on the chloride concentration and was attributed to the structural changes occurring in the cobalt( II) species. The STAR and STAR FA programs were applied to identify the complex ionic species and to calculate the stability constants of Co( II) complexes formed in this solvent. The results indicate the highest probability of formation of the following complex species: Co(NO3)(4)(2-), Co(NO3)(2)Cl-2(2-), and CoCl42-. Stability constants of each complex were presented for the equilibria occurring at 313, 333, 353, and 363 K. Distribution of the Co( II) species was also calculated over the ranges of chloride concentration and temperature investigated.",
journal = "Journal of Solution Chemistry",
title = "Cobalt(II) chloride complex formation in acetamide-calcium nitrate tetrahydrate melts",
volume = "33",
number = "3",
pages = "287-300",
doi = "10.1023/B:JOSL.0000035361.89473.a4"
}

Savović, J., Nikolic, R.,& Veselinović, D. S.. (2004). Cobalt(II) chloride complex formation in acetamide-calcium nitrate tetrahydrate melts. in Journal of Solution Chemistry, 33(3), 287-300.
https://doi.org/10.1023/B:JOSL.0000035361.89473.a4

Savović J, Nikolic R, Veselinović DS. Cobalt(II) chloride complex formation in acetamide-calcium nitrate tetrahydrate melts. in Journal of Solution Chemistry. 2004;33(3):287-300.
doi:10.1023/B:JOSL.0000035361.89473.a4 .

Savović, Jelena, Nikolic, R, Veselinović, Dragan S., "Cobalt(II) chloride complex formation in acetamide-calcium nitrate tetrahydrate melts" in Journal of Solution Chemistry, 33, no. 3 (2004):287-300,
https://doi.org/10.1023/B:JOSL.0000035361.89473.a4 . .

TY  - JOUR
AU  - Babić, Dragan
AU  - Nikolic, R
AU  - Gadžurić, Slobodan
AU  - Zsigrai, Istvan J.
PY  - 2001
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2505
AB  - Specific conductivity of molten mixtures of acetamide with following acetate salts was measured at 83 +/- 0.1degreesC : a) acetamide - anhydrous sodium acetate (up to 0.051 mole fraction), b) acetainide sodium acetate trihydrate (entire concentration range) and c) acetamide - zinc acetate dihydrate ( up to 0.24 mole fraction). Selected composition of all three mixtures, with low melting points were chosen for the studies of the changes of conductance with temperature. The mixtures: with sodium acetate both anhydrous and hydrated showed fairly high specific conductivity (approximate to10(-2) S/cm), nearly two orders of magnitude higher than the mixture with hydrated zinc acetate. Molar conductivity was also calculated. The results were discussed in terms of acetamide-salt-water interactions. Attempts were made to calculate the degree of dissociation of the salts in molten acetamide. The results were compared with the data obtained from earlier thermochemical studies of the same melt systems.
T2  - High Temperature Material Processes
T1  - Electrical conductivity of the acetamide-acetate salt melts
VL  - 5
IS  - 4
SP  - 595
EP  - 602
UR  - https://hdl.handle.net/21.15107/rcub_vinar_2505
ER  - 

@article{
author = "Babić, Dragan and Nikolic, R and Gadžurić, Slobodan and Zsigrai, Istvan J.",
year = "2001",
abstract = "Specific conductivity of molten mixtures of acetamide with following acetate salts was measured at 83 +/- 0.1degreesC : a) acetamide - anhydrous sodium acetate (up to 0.051 mole fraction), b) acetainide sodium acetate trihydrate (entire concentration range) and c) acetamide - zinc acetate dihydrate ( up to 0.24 mole fraction). Selected composition of all three mixtures, with low melting points were chosen for the studies of the changes of conductance with temperature. The mixtures: with sodium acetate both anhydrous and hydrated showed fairly high specific conductivity (approximate to10(-2) S/cm), nearly two orders of magnitude higher than the mixture with hydrated zinc acetate. Molar conductivity was also calculated. The results were discussed in terms of acetamide-salt-water interactions. Attempts were made to calculate the degree of dissociation of the salts in molten acetamide. The results were compared with the data obtained from earlier thermochemical studies of the same melt systems.",
journal = "High Temperature Material Processes",
title = "Electrical conductivity of the acetamide-acetate salt melts",
volume = "5",
number = "4",
pages = "595-602",
url = "https://hdl.handle.net/21.15107/rcub_vinar_2505"
}

Babić, D., Nikolic, R., Gadžurić, S.,& Zsigrai, I. J.. (2001). Electrical conductivity of the acetamide-acetate salt melts. in High Temperature Material Processes, 5(4), 595-602.
https://hdl.handle.net/21.15107/rcub_vinar_2505

Babić D, Nikolic R, Gadžurić S, Zsigrai IJ. Electrical conductivity of the acetamide-acetate salt melts. in High Temperature Material Processes. 2001;5(4):595-602.
https://hdl.handle.net/21.15107/rcub_vinar_2505 .

Babić, Dragan, Nikolic, R, Gadžurić, Slobodan, Zsigrai, Istvan J., "Electrical conductivity of the acetamide-acetate salt melts" in High Temperature Material Processes, 5, no. 4 (2001):595-602,
https://hdl.handle.net/21.15107/rcub_vinar_2505 .

TY  - JOUR
AU  - Zsigrai, Istvan J.
AU  - Gadžurić, Slobodan
AU  - Nikolic, R
PY  - 2001
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2504
AB  - In this work a series of spectrophotometric measurements of cobalt(II) chloride in calcium nitrate tetrahydrate melts containing variable amounts of calcium chloride (from 0 to 3.1 mol dm(-3)) were performed at different temperatures from 40 to 70 degreesC. The solutions in pure calcium nitrate tetrahydrate showed octahedral co-ordination, the position of the absorption maximum being at 19420 cm(-1) (512 nm). Addition of chloride caused a shift of the absorption maximum toward lower energies and a large increase of the absorption coefficient indicating a change from octahedral to tetrahedral or distorted octahedral co-ordination, characteristic for cobalt(II) chloride complexes in aqueous nitrate melts. The position of the absorption maximum of the octahedral and tetrahedral complexes and the values of the molar absorption coefficients indicates some co-ordination also by nitrate ion. Stability constants for [CO(NO3)(4)](2-), [CO(NO3)(2)Cl-2](2-) and [COCl4](2-) and the corresponding resolved species spectra are reported.
T2  - High Temperature Material Processes
T1  - Cobalt(II) chloride complexes in calcium nitrate tetrahydrate melt
VL  - 5
IS  - 4
SP  - 573
EP  - 581
UR  - https://hdl.handle.net/21.15107/rcub_vinar_2504
ER  - 

@article{
author = "Zsigrai, Istvan J. and Gadžurić, Slobodan and Nikolic, R",
year = "2001",
abstract = "In this work a series of spectrophotometric measurements of cobalt(II) chloride in calcium nitrate tetrahydrate melts containing variable amounts of calcium chloride (from 0 to 3.1 mol dm(-3)) were performed at different temperatures from 40 to 70 degreesC. The solutions in pure calcium nitrate tetrahydrate showed octahedral co-ordination, the position of the absorption maximum being at 19420 cm(-1) (512 nm). Addition of chloride caused a shift of the absorption maximum toward lower energies and a large increase of the absorption coefficient indicating a change from octahedral to tetrahedral or distorted octahedral co-ordination, characteristic for cobalt(II) chloride complexes in aqueous nitrate melts. The position of the absorption maximum of the octahedral and tetrahedral complexes and the values of the molar absorption coefficients indicates some co-ordination also by nitrate ion. Stability constants for [CO(NO3)(4)](2-), [CO(NO3)(2)Cl-2](2-) and [COCl4](2-) and the corresponding resolved species spectra are reported.",
journal = "High Temperature Material Processes",
title = "Cobalt(II) chloride complexes in calcium nitrate tetrahydrate melt",
volume = "5",
number = "4",
pages = "573-581",
url = "https://hdl.handle.net/21.15107/rcub_vinar_2504"
}

Zsigrai, I. J., Gadžurić, S.,& Nikolic, R.. (2001). Cobalt(II) chloride complexes in calcium nitrate tetrahydrate melt. in High Temperature Material Processes, 5(4), 573-581.
https://hdl.handle.net/21.15107/rcub_vinar_2504

Zsigrai IJ, Gadžurić S, Nikolic R. Cobalt(II) chloride complexes in calcium nitrate tetrahydrate melt. in High Temperature Material Processes. 2001;5(4):573-581.
https://hdl.handle.net/21.15107/rcub_vinar_2504 .

Zsigrai, Istvan J., Gadžurić, Slobodan, Nikolic, R, "Cobalt(II) chloride complexes in calcium nitrate tetrahydrate melt" in High Temperature Material Processes, 5, no. 4 (2001):573-581,
https://hdl.handle.net/21.15107/rcub_vinar_2504 .

TY  - JOUR
AU  - Marinković, Miloš
AU  - Nikolić, Ružica M.
AU  - Savović, Jelena
AU  - Gadžurić, Slobodan
AU  - Zsigrai, Istvan J.
PY  - 1998
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2119
AB  - The possibility to combine two physico-chemical phenomena is studied in this work in order to attain simultaneous control of temperature and light intensity in a greenhouse: (a) isothermal heat storage in phase change materials and (b) thermochromic behavior of complex compounds dissolved in the phase change materials. Two binary mixtures melting near the ambient temperature were studied: (a) 0.925 Ca(NO3)(2) . 4.06 H2O + 0.075 CaCl2 . 6.11 H2O melting at 35.6 degrees C and (b) 0.9 CH3CONH2 + 0.1 Ca(NO3)(2) . 4 H2O, melting at 27.7 degrees C. The melting temperature, the enthalpy of fusion and the heat capacity of both mixtures were determined from DSC measurements. Both mixtures showed to be suitable solvents for the formation of consecutive cobalt(II) chloride complexes. The compositions of the complex compounds were adjusted in each mixture so that the absorption spectra in visible spectral range exhibited low absorbance at the melting temperature and a pronounced increase of the absorbance and/or change of color with the increase of temperature in the range relevant for passive solar energy receivers. The combined latent heat storage and the outstanding reversible change of the optical properties of the dissolved complex compounds with temperature is proposed to be applied in solar heated agricultural greenhouses in areas with fluctuating climate conditions. The increase of absorbance with temperature acts as an auto-regulated shading protection from overheating. (C) 1998 Elsevier Science B.V. All rights reserved.
T2  - Solar Energy Materials and Solar Cells
T1  - Thermochromic complex compounds in phase change materials: Possible application in an agricultural greenhouse
VL  - 51
IS  - 3-4
SP  - 401
EP  - 411
DO  - 10.1016/S0927-0248(97)00259-6
ER  - 

@article{
author = "Marinković, Miloš and Nikolić, Ružica M. and Savović, Jelena and Gadžurić, Slobodan and Zsigrai, Istvan J.",
year = "1998",
abstract = "The possibility to combine two physico-chemical phenomena is studied in this work in order to attain simultaneous control of temperature and light intensity in a greenhouse: (a) isothermal heat storage in phase change materials and (b) thermochromic behavior of complex compounds dissolved in the phase change materials. Two binary mixtures melting near the ambient temperature were studied: (a) 0.925 Ca(NO3)(2) . 4.06 H2O + 0.075 CaCl2 . 6.11 H2O melting at 35.6 degrees C and (b) 0.9 CH3CONH2 + 0.1 Ca(NO3)(2) . 4 H2O, melting at 27.7 degrees C. The melting temperature, the enthalpy of fusion and the heat capacity of both mixtures were determined from DSC measurements. Both mixtures showed to be suitable solvents for the formation of consecutive cobalt(II) chloride complexes. The compositions of the complex compounds were adjusted in each mixture so that the absorption spectra in visible spectral range exhibited low absorbance at the melting temperature and a pronounced increase of the absorbance and/or change of color with the increase of temperature in the range relevant for passive solar energy receivers. The combined latent heat storage and the outstanding reversible change of the optical properties of the dissolved complex compounds with temperature is proposed to be applied in solar heated agricultural greenhouses in areas with fluctuating climate conditions. The increase of absorbance with temperature acts as an auto-regulated shading protection from overheating. (C) 1998 Elsevier Science B.V. All rights reserved.",
journal = "Solar Energy Materials and Solar Cells",
title = "Thermochromic complex compounds in phase change materials: Possible application in an agricultural greenhouse",
volume = "51",
number = "3-4",
pages = "401-411",
doi = "10.1016/S0927-0248(97)00259-6"
}

Marinković, M., Nikolić, R. M., Savović, J., Gadžurić, S.,& Zsigrai, I. J.. (1998). Thermochromic complex compounds in phase change materials: Possible application in an agricultural greenhouse. in Solar Energy Materials and Solar Cells, 51(3-4), 401-411.
https://doi.org/10.1016/S0927-0248(97)00259-6

Marinković M, Nikolić RM, Savović J, Gadžurić S, Zsigrai IJ. Thermochromic complex compounds in phase change materials: Possible application in an agricultural greenhouse. in Solar Energy Materials and Solar Cells. 1998;51(3-4):401-411.
doi:10.1016/S0927-0248(97)00259-6 .

Marinković, Miloš, Nikolić, Ružica M., Savović, Jelena, Gadžurić, Slobodan, Zsigrai, Istvan J., "Thermochromic complex compounds in phase change materials: Possible application in an agricultural greenhouse" in Solar Energy Materials and Solar Cells, 51, no. 3-4 (1998):401-411,
https://doi.org/10.1016/S0927-0248(97)00259-6 . .

TY  - JOUR
AU  - Nikolić, Ružica M.
AU  - Marinković, Miloš
AU  - Pavlović, Mirjana S.
PY  - 1996
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1988
AB  - The melting point depression of acetamide on addition of anhydrous sodium acetate and sodium acetate trihydrate was followed by DSC. Two sets of measurements were made for two crystalline forms in which the melts crystallized. From cryoscopic data, activity coefficients of acetamide were calculated in the concentration range 0 to 0.390 mole fraction of sodium acetate and 0 to 0.376 mole fraction of sodium acetate trihydrate. Activities of the salt components were calculated from the activities of the solvent using a simple analytical method. From melting point depression data and the known molar cryoscopic constant of acetamide, the Vant Hoff dissociation factor was calculated for both anhydrous and hydrated sodium acetate in the concentration ranges studied.
T2  - Thermochimica Acta
T1  - Cryoscopic behavior in the binary mixtures of acetamide-sodium acetate and acetamide-sodium acetate trihydrate
VL  - 276
SP  - 17
EP  - 25
DO  - 10.1016/0040-6031(95)02774-2
ER  - 

@article{
author = "Nikolić, Ružica M. and Marinković, Miloš and Pavlović, Mirjana S.",
year = "1996",
abstract = "The melting point depression of acetamide on addition of anhydrous sodium acetate and sodium acetate trihydrate was followed by DSC. Two sets of measurements were made for two crystalline forms in which the melts crystallized. From cryoscopic data, activity coefficients of acetamide were calculated in the concentration range 0 to 0.390 mole fraction of sodium acetate and 0 to 0.376 mole fraction of sodium acetate trihydrate. Activities of the salt components were calculated from the activities of the solvent using a simple analytical method. From melting point depression data and the known molar cryoscopic constant of acetamide, the Vant Hoff dissociation factor was calculated for both anhydrous and hydrated sodium acetate in the concentration ranges studied.",
journal = "Thermochimica Acta",
title = "Cryoscopic behavior in the binary mixtures of acetamide-sodium acetate and acetamide-sodium acetate trihydrate",
volume = "276",
pages = "17-25",
doi = "10.1016/0040-6031(95)02774-2"
}

Nikolić, R. M., Marinković, M.,& Pavlović, M. S.. (1996). Cryoscopic behavior in the binary mixtures of acetamide-sodium acetate and acetamide-sodium acetate trihydrate. in Thermochimica Acta, 276, 17-25.
https://doi.org/10.1016/0040-6031(95)02774-2

Nikolić RM, Marinković M, Pavlović MS. Cryoscopic behavior in the binary mixtures of acetamide-sodium acetate and acetamide-sodium acetate trihydrate. in Thermochimica Acta. 1996;276:17-25.
doi:10.1016/0040-6031(95)02774-2 .

Nikolić, Ružica M., Marinković, Miloš, Pavlović, Mirjana S., "Cryoscopic behavior in the binary mixtures of acetamide-sodium acetate and acetamide-sodium acetate trihydrate" in Thermochimica Acta, 276 (1996):17-25,
https://doi.org/10.1016/0040-6031(95)02774-2 . .

TY  - JOUR
AU  - Savović, Jelena
AU  - Nikolić, Ružica M.
AU  - Kerridge, David H.
PY  - 1996
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1984
AB  - The absorption spectra of Co(II) chloride species were studied in molten acetamide containing variable concentration of chloride ligand, in the wavelength range 400-800 nm, at 90 degrees C. The stepwise formation of CoClj(2-j) complexes (j = 1-4) was observed. Addition of chloride ligand (up to 4 molar) dramatically changed Co(II) absorption spectra due to change in co-ordination from octahedral through a severely distorted octahedral to tetrahedral co-ordination. Overall equilibrium constants beta(j) and consecutive stability constants K-j(j = 1-4) were calculated using SPELMA program for simultaneous computation of equilibrium constants and molar absorption coefficients for each complex species. Distribution of the Co(II) species was also calculated in the studied ligand concentration range.
T2  - Fluid Phase Equilibria
T1  - Cobalt(II) chloride complexes in molten acetamide
VL  - 118
IS  - 1
SP  - 143
EP  - 151
DO  - 10.1016/0378-3812(95)02844-7
ER  - 

@article{
author = "Savović, Jelena and Nikolić, Ružica M. and Kerridge, David H.",
year = "1996",
abstract = "The absorption spectra of Co(II) chloride species were studied in molten acetamide containing variable concentration of chloride ligand, in the wavelength range 400-800 nm, at 90 degrees C. The stepwise formation of CoClj(2-j) complexes (j = 1-4) was observed. Addition of chloride ligand (up to 4 molar) dramatically changed Co(II) absorption spectra due to change in co-ordination from octahedral through a severely distorted octahedral to tetrahedral co-ordination. Overall equilibrium constants beta(j) and consecutive stability constants K-j(j = 1-4) were calculated using SPELMA program for simultaneous computation of equilibrium constants and molar absorption coefficients for each complex species. Distribution of the Co(II) species was also calculated in the studied ligand concentration range.",
journal = "Fluid Phase Equilibria",
title = "Cobalt(II) chloride complexes in molten acetamide",
volume = "118",
number = "1",
pages = "143-151",
doi = "10.1016/0378-3812(95)02844-7"
}

Savović, J., Nikolić, R. M.,& Kerridge, D. H.. (1996). Cobalt(II) chloride complexes in molten acetamide. in Fluid Phase Equilibria, 118(1), 143-151.
https://doi.org/10.1016/0378-3812(95)02844-7

Savović J, Nikolić RM, Kerridge DH. Cobalt(II) chloride complexes in molten acetamide. in Fluid Phase Equilibria. 1996;118(1):143-151.
doi:10.1016/0378-3812(95)02844-7 .

Savović, Jelena, Nikolić, Ružica M., Kerridge, David H., "Cobalt(II) chloride complexes in molten acetamide" in Fluid Phase Equilibria, 118, no. 1 (1996):143-151,
https://doi.org/10.1016/0378-3812(95)02844-7 . .