TY  - JOUR
AU  - Dimitrijević, Stevan
AU  - Vurdelja, Borislava D.
AU  - Dimitrijević, Silvana
AU  - Veljković, Filip M.
AU  - Kamberović, Željko
AU  - Veličković, Suzana
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4456
AB  - Corrosion products formed on the surface of two silver brazing alloys after the potentiostatic polarization in 3.5% sodium chloride solution were characterized by the standard methods such as, the X-ray diffraction, microRaman spectroscopy, and scanning electron microscopy with energy-dispersive spectroscopy. This paper presents the results of a laser desorption/ionization mass spectrometry (LDI MS) analysis as a new approach to the characterization of corrosion products. The potential of the anodic polarization was 0.5 V versus saturated calomel electrode, and the process duration was 300 s. The corrosion layers on both investigated alloys were similar in composition with cuprous chloride and silver chloride as the main components and had strong indications of cuprous oxide formation. The major difference between these two layers was the existence of zinc hydroxychioride as the corrosion product of Ag-Cu-Zn alloy. Palladium compounds were not found in the case of Ag-Cu-Pd alloy. The results of different methods have shown a good consistency. Complementarity between the used methods was useful in the interpretation of the results for each used method. This study has demonstrated that LDI MS can be used as an efficient additional method together with the traditional ones.
PB  - Walter de Gruyter Gmbh, Berlin
T2  - Corrosion Reviews
T1  - Complementary methods for characterization of the corrosion products on the surface of Ag60Cu26Zn14 and Ag58.5Cu31.5Pd10 brazing alloys
EP  - 125
IS  - 2
SP  - 111
VL  - 38
DO  - 10.1515/corrrev-2019-0067
ER  - 

@article{
author = "Dimitrijević, Stevan and Vurdelja, Borislava D. and Dimitrijević, Silvana and Veljković, Filip M. and Kamberović, Željko and Veličković, Suzana",
year = "2020",
abstract = "Corrosion products formed on the surface of two silver brazing alloys after the potentiostatic polarization in 3.5% sodium chloride solution were characterized by the standard methods such as, the X-ray diffraction, microRaman spectroscopy, and scanning electron microscopy with energy-dispersive spectroscopy. This paper presents the results of a laser desorption/ionization mass spectrometry (LDI MS) analysis as a new approach to the characterization of corrosion products. The potential of the anodic polarization was 0.5 V versus saturated calomel electrode, and the process duration was 300 s. The corrosion layers on both investigated alloys were similar in composition with cuprous chloride and silver chloride as the main components and had strong indications of cuprous oxide formation. The major difference between these two layers was the existence of zinc hydroxychioride as the corrosion product of Ag-Cu-Zn alloy. Palladium compounds were not found in the case of Ag-Cu-Pd alloy. The results of different methods have shown a good consistency. Complementarity between the used methods was useful in the interpretation of the results for each used method. This study has demonstrated that LDI MS can be used as an efficient additional method together with the traditional ones.",
publisher = "Walter de Gruyter Gmbh, Berlin",
journal = "Corrosion Reviews",
title = "Complementary methods for characterization of the corrosion products on the surface of Ag60Cu26Zn14 and Ag58.5Cu31.5Pd10 brazing alloys",
pages = "125-111",
number = "2",
volume = "38",
doi = "10.1515/corrrev-2019-0067"
}

Dimitrijević, S., Vurdelja, B. D., Dimitrijević, S., Veljković, F. M., Kamberović, Ž.,& Veličković, S.. (2020). Complementary methods for characterization of the corrosion products on the surface of Ag60Cu26Zn14 and Ag58.5Cu31.5Pd10 brazing alloys. in Corrosion Reviews
Walter de Gruyter Gmbh, Berlin., 38(2), 111-125.
https://doi.org/10.1515/corrrev-2019-0067

Dimitrijević S, Vurdelja BD, Dimitrijević S, Veljković FM, Kamberović Ž, Veličković S. Complementary methods for characterization of the corrosion products on the surface of Ag60Cu26Zn14 and Ag58.5Cu31.5Pd10 brazing alloys. in Corrosion Reviews. 2020;38(2):111-125.
doi:10.1515/corrrev-2019-0067 .

Dimitrijević, Stevan, Vurdelja, Borislava D., Dimitrijević, Silvana, Veljković, Filip M., Kamberović, Željko, Veličković, Suzana, "Complementary methods for characterization of the corrosion products on the surface of Ag60Cu26Zn14 and Ag58.5Cu31.5Pd10 brazing alloys" in Corrosion Reviews, 38, no. 2 (2020):111-125,
https://doi.org/10.1515/corrrev-2019-0067 . .

TY  - JOUR
AU  - Milovanović, Branislav
AU  - Milovanović, Milan
AU  - Veličković, Suzana
AU  - Veljković, Filip M.
AU  - Perić-Grujić, Aleksandra
AU  - Jerosimić, Stanka
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4053
AB  - Small heterogeneous potassium-iodide clusters are investigated by means of ab initio electronic structural methods together with experimental production and detection in mass spectrometry. Experiments were done by using Knudsen cell mass spectrometry (KCMS) modification method, which provided simultaneous generating of all KnI0,+1 (n = 2-6) clusters at once. Clusters with more than two potassium atoms are produced for the first time. The lowest lying isomers of those KnI0,+1 (n = 2-6) clusters were found by using a random-kick procedure. The best description of growth of these clusters is the addition of one potassium atom to a smaller-neighbor cluster. Subsequently, stability of these species was examined. In spite of general trend of decreasing of binding energies, the closed-shell species have slightly larger stability with respect to the open-shell species. Alternation of dissociation energies between closed-shell and open-shell clusters is presented. Experimental setup also allows determination of ionization energies of clusters: the obtained values are in the range of 3.46-3.98 eV, which classify these clusters as "superalkali." For closed-shell clusters, the theoretical adiabatic ionization energies are close to experimental values, whereas in the case of open-shell clusters, the vertical ionization energies are those that are close to experimental values.
PB  - Wiley, Hoboken
T2  - International Journal of Quantum Chemistry
T1  - Theoretical and experimental investigation of geometry and stability of small potassium-iodide KnI (n=2-6) clusters
IS  - 22
VL  - 119
DO  - 10.1002/qua.26009
ER  - 

@article{
author = "Milovanović, Branislav and Milovanović, Milan and Veličković, Suzana and Veljković, Filip M. and Perić-Grujić, Aleksandra and Jerosimić, Stanka",
year = "2019",
abstract = "Small heterogeneous potassium-iodide clusters are investigated by means of ab initio electronic structural methods together with experimental production and detection in mass spectrometry. Experiments were done by using Knudsen cell mass spectrometry (KCMS) modification method, which provided simultaneous generating of all KnI0,+1 (n = 2-6) clusters at once. Clusters with more than two potassium atoms are produced for the first time. The lowest lying isomers of those KnI0,+1 (n = 2-6) clusters were found by using a random-kick procedure. The best description of growth of these clusters is the addition of one potassium atom to a smaller-neighbor cluster. Subsequently, stability of these species was examined. In spite of general trend of decreasing of binding energies, the closed-shell species have slightly larger stability with respect to the open-shell species. Alternation of dissociation energies between closed-shell and open-shell clusters is presented. Experimental setup also allows determination of ionization energies of clusters: the obtained values are in the range of 3.46-3.98 eV, which classify these clusters as "superalkali." For closed-shell clusters, the theoretical adiabatic ionization energies are close to experimental values, whereas in the case of open-shell clusters, the vertical ionization energies are those that are close to experimental values.",
publisher = "Wiley, Hoboken",
journal = "International Journal of Quantum Chemistry",
title = "Theoretical and experimental investigation of geometry and stability of small potassium-iodide KnI (n=2-6) clusters",
number = "22",
volume = "119",
doi = "10.1002/qua.26009"
}

Milovanović, B., Milovanović, M., Veličković, S., Veljković, F. M., Perić-Grujić, A.,& Jerosimić, S.. (2019). Theoretical and experimental investigation of geometry and stability of small potassium-iodide KnI (n=2-6) clusters. in International Journal of Quantum Chemistry
Wiley, Hoboken., 119(22).
https://doi.org/10.1002/qua.26009

Milovanović B, Milovanović M, Veličković S, Veljković FM, Perić-Grujić A, Jerosimić S. Theoretical and experimental investigation of geometry and stability of small potassium-iodide KnI (n=2-6) clusters. in International Journal of Quantum Chemistry. 2019;119(22).
doi:10.1002/qua.26009 .

Milovanović, Branislav, Milovanović, Milan, Veličković, Suzana, Veljković, Filip M., Perić-Grujić, Aleksandra, Jerosimić, Stanka, "Theoretical and experimental investigation of geometry and stability of small potassium-iodide KnI (n=2-6) clusters" in International Journal of Quantum Chemistry, 119, no. 22 (2019),
https://doi.org/10.1002/qua.26009 . .

TY  - JOUR
AU  - Vurdelja, Borislava D.
AU  - Dimitrijević, Stevan P.
AU  - Dimitrijević, Silvana B.
AU  - Kamberović, Željko J.
AU  - Veličković, Suzana R.
PY  - 2017
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3656
AB  - This work is the first to demonstrate the possibilities of direct analysis of the corrosion film formed on Ag43Cu37Zn20 alloy using laser desorption/ionization (LDI) on a commercial matrix-assisted LDI time of flight mass spectrometry (MS) instrument. In the LDI mass spectra measured from the water solution of the corrosion film, the ion species Zn+, Zn(H2O)(+), AgH+, Cu2H+, Cu2O(OH)+, Cu3O(OH)(+) (high intensity), and Cu(OH)(H2O)(+), ZnCl(OH)(H2O)(+), AgCl+, CuCl+ (low intensity) were identified. The LDI mass spectra of the propan-2-ol solution of the corrosion film contains the ions Zn5Cl(OH)(3)(H2O)(11)(+), Zn5Cl2 (OH)(8) (H2O)(6)(+), and Zn5Cl2 (OH)(H2O)(14)(+). Mass spectra were observed at laser energies in the range of 1340-1860 arbitrary units in positive ion mode. Previously, Raman spectra and X-ray diffraction (XRD) analysis of the same anodic film have shown similar results as LDI MS -that the anodic film contains the mixture of Ag, Cu2O, CuCl, Zn5Cl2(OH)(8) center dot H2O, and beta-Zn(OH) Cl. LDI MS could be a complementary method for XRD and Raman, as demonstrated in this investigation. The LDI MS method greatly reduces the analysis time and amount of the sample compared to traditional methods. For this reason, the LDI MS method can be a useful tool for the fast qualitative screening of corrosion films.
PB  - Walter de Gruyter Gmbh
T2  - Corrosion Reviews
T1  - Characterization of the Ag43Cu37Zn20 alloy surface after potentiostatic polarization using LDI-TOF mass spectrometry
EP  - 481
IS  - 6
SP  - 473
VL  - 35
DO  - 10.1515/corrrev-2017-0065
ER  - 

@article{
author = "Vurdelja, Borislava D. and Dimitrijević, Stevan P. and Dimitrijević, Silvana B. and Kamberović, Željko J. and Veličković, Suzana R.",
year = "2017",
abstract = "This work is the first to demonstrate the possibilities of direct analysis of the corrosion film formed on Ag43Cu37Zn20 alloy using laser desorption/ionization (LDI) on a commercial matrix-assisted LDI time of flight mass spectrometry (MS) instrument. In the LDI mass spectra measured from the water solution of the corrosion film, the ion species Zn+, Zn(H2O)(+), AgH+, Cu2H+, Cu2O(OH)+, Cu3O(OH)(+) (high intensity), and Cu(OH)(H2O)(+), ZnCl(OH)(H2O)(+), AgCl+, CuCl+ (low intensity) were identified. The LDI mass spectra of the propan-2-ol solution of the corrosion film contains the ions Zn5Cl(OH)(3)(H2O)(11)(+), Zn5Cl2 (OH)(8) (H2O)(6)(+), and Zn5Cl2 (OH)(H2O)(14)(+). Mass spectra were observed at laser energies in the range of 1340-1860 arbitrary units in positive ion mode. Previously, Raman spectra and X-ray diffraction (XRD) analysis of the same anodic film have shown similar results as LDI MS -that the anodic film contains the mixture of Ag, Cu2O, CuCl, Zn5Cl2(OH)(8) center dot H2O, and beta-Zn(OH) Cl. LDI MS could be a complementary method for XRD and Raman, as demonstrated in this investigation. The LDI MS method greatly reduces the analysis time and amount of the sample compared to traditional methods. For this reason, the LDI MS method can be a useful tool for the fast qualitative screening of corrosion films.",
publisher = "Walter de Gruyter Gmbh",
journal = "Corrosion Reviews",
title = "Characterization of the Ag43Cu37Zn20 alloy surface after potentiostatic polarization using LDI-TOF mass spectrometry",
pages = "481-473",
number = "6",
volume = "35",
doi = "10.1515/corrrev-2017-0065"
}

Vurdelja, B. D., Dimitrijević, S. P., Dimitrijević, S. B., Kamberović, Ž. J.,& Veličković, S. R.. (2017). Characterization of the Ag43Cu37Zn20 alloy surface after potentiostatic polarization using LDI-TOF mass spectrometry. in Corrosion Reviews
Walter de Gruyter Gmbh., 35(6), 473-481.
https://doi.org/10.1515/corrrev-2017-0065

Vurdelja BD, Dimitrijević SP, Dimitrijević SB, Kamberović ŽJ, Veličković SR. Characterization of the Ag43Cu37Zn20 alloy surface after potentiostatic polarization using LDI-TOF mass spectrometry. in Corrosion Reviews. 2017;35(6):473-481.
doi:10.1515/corrrev-2017-0065 .

Vurdelja, Borislava D., Dimitrijević, Stevan P., Dimitrijević, Silvana B., Kamberović, Željko J., Veličković, Suzana R., "Characterization of the Ag43Cu37Zn20 alloy surface after potentiostatic polarization using LDI-TOF mass spectrometry" in Corrosion Reviews, 35, no. 6 (2017):473-481,
https://doi.org/10.1515/corrrev-2017-0065 . .

TY  - JOUR
AU  - Veljković, Filip M.
AU  - Perić-Grujić, Aleksandra
AU  - Veličković, Suzana
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3244
AB  - Knudsen effusion mass spectrometry or high-temperature method of mass spectrometry for decades gives new information about saturated vapor of hardly volatile compounds and it is an important method in the discovery of many new molecules, radicals, ions and clusters present in the gas phase. Since pioneering works until now, this method has been successfully applied to a large number of systems (ores, oxides, ceramics, glass materials, borides, carbides, sulfides, nitrates, metals, fullerenes, etc.) which led to the establishment of various research branches such as chemistry of clusters. This paper describes the basic principles of Knudsen cell use for both identification of chemical species created in the process of evaporation and determination of their ionization energies. Depending on detected ions intensities and the partial pressure of each gaseous component, as well as on changes in partial pressure with temperature, Knudsen cell mass spectrometry enables the determination of thermodynamic parameters of the tested system. A special attention is paid to its application in the field of small heterogeneous and homogeneous clusters of alkali metals. Furthermore, experimental results for thermodynamic parameters of some clusters, as well as capabilities of non-standard ways of using Knudsen cells in the process of synthesis of new clusters are presented herein.
PB  - Savez hemijskih inženjera, Beograd
T2  - Hemijska industrija
T1  - Mass spectrometric production of heterogeneous metal clusters using knudsen cell
EP  - 637
IS  - 6
SP  - 629
VL  - 70
DO  - 10.2298/HEMIND150922070V
ER  - 

@article{
author = "Veljković, Filip M. and Perić-Grujić, Aleksandra and Veličković, Suzana",
year = "2016",
abstract = "Knudsen effusion mass spectrometry or high-temperature method of mass spectrometry for decades gives new information about saturated vapor of hardly volatile compounds and it is an important method in the discovery of many new molecules, radicals, ions and clusters present in the gas phase. Since pioneering works until now, this method has been successfully applied to a large number of systems (ores, oxides, ceramics, glass materials, borides, carbides, sulfides, nitrates, metals, fullerenes, etc.) which led to the establishment of various research branches such as chemistry of clusters. This paper describes the basic principles of Knudsen cell use for both identification of chemical species created in the process of evaporation and determination of their ionization energies. Depending on detected ions intensities and the partial pressure of each gaseous component, as well as on changes in partial pressure with temperature, Knudsen cell mass spectrometry enables the determination of thermodynamic parameters of the tested system. A special attention is paid to its application in the field of small heterogeneous and homogeneous clusters of alkali metals. Furthermore, experimental results for thermodynamic parameters of some clusters, as well as capabilities of non-standard ways of using Knudsen cells in the process of synthesis of new clusters are presented herein.",
publisher = "Savez hemijskih inženjera, Beograd",
journal = "Hemijska industrija",
title = "Mass spectrometric production of heterogeneous metal clusters using knudsen cell",
pages = "637-629",
number = "6",
volume = "70",
doi = "10.2298/HEMIND150922070V"
}

Veljković, F. M., Perić-Grujić, A.,& Veličković, S.. (2016). Mass spectrometric production of heterogeneous metal clusters using knudsen cell. in Hemijska industrija
Savez hemijskih inženjera, Beograd., 70(6), 629-637.
https://doi.org/10.2298/HEMIND150922070V

Veljković FM, Perić-Grujić A, Veličković S. Mass spectrometric production of heterogeneous metal clusters using knudsen cell. in Hemijska industrija. 2016;70(6):629-637.
doi:10.2298/HEMIND150922070V .

Veljković, Filip M., Perić-Grujić, Aleksandra, Veličković, Suzana, "Mass spectrometric production of heterogeneous metal clusters using knudsen cell" in Hemijska industrija, 70, no. 6 (2016):629-637,
https://doi.org/10.2298/HEMIND150922070V . .

TY  - CONF
AU  - Dimitrijević, Silvana
AU  - Milošević, Maja
AU  - Veličković, Suzana
AU  - Alagić, Slađana
AU  - Rajčić-Vujasinović, Mirjana
AU  - Dimitrijević, Stevan
AU  - Trumić, Biserka
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7003
AB  - In this work, the possibilities of a mass spectrometry approach towards the characterizations of the electrolyte for decorative gold plating based on mercaptotriazole were studied. All mass spectra were obtained using laser desorption ionization (LDI) method on a commercial matrix assisted laser desorption ionization – time of flight (MALDI-TOF) mass spectrometer. The LDI MS spectra of chloroauric acid gave evidence of the presence of a variety of monomeric and polymeric complexes. LDI MS spectra of the electrolyte obtained from chloroauric acid, glycine and mercaptotriazole revealed existence of the ion at m/z 472 which indicated that the complex [Au(NH2CH2COOH)(C2H2N3S)2]- has been formed.
PB  - Bor : Mining and Metallurgy Institute
C3  - Proceedings / 47th International October Conference on Mining and Metallurgy - IOC 2015, 4th-6th October 2015, Bor Lake, Serbia
T1  - MASS SPECTROMETRY FOR STRUCTURAL CHARACTERIZATION OF NON-CYANIDE GOLD COMPLEX
EP  - 386
SP  - 379
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7003
ER  - 

@conference{
author = "Dimitrijević, Silvana and Milošević, Maja and Veličković, Suzana and Alagić, Slađana and Rajčić-Vujasinović, Mirjana and Dimitrijević, Stevan and Trumić, Biserka",
year = "2015",
abstract = "In this work, the possibilities of a mass spectrometry approach towards the characterizations of the electrolyte for decorative gold plating based on mercaptotriazole were studied. All mass spectra were obtained using laser desorption ionization (LDI) method on a commercial matrix assisted laser desorption ionization – time of flight (MALDI-TOF) mass spectrometer. The LDI MS spectra of chloroauric acid gave evidence of the presence of a variety of monomeric and polymeric complexes. LDI MS spectra of the electrolyte obtained from chloroauric acid, glycine and mercaptotriazole revealed existence of the ion at m/z 472 which indicated that the complex [Au(NH2CH2COOH)(C2H2N3S)2]- has been formed.",
publisher = "Bor : Mining and Metallurgy Institute",
journal = "Proceedings / 47th International October Conference on Mining and Metallurgy - IOC 2015, 4th-6th October 2015, Bor Lake, Serbia",
title = "MASS SPECTROMETRY FOR STRUCTURAL CHARACTERIZATION OF NON-CYANIDE GOLD COMPLEX",
pages = "386-379",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7003"
}

Dimitrijević, S., Milošević, M., Veličković, S., Alagić, S., Rajčić-Vujasinović, M., Dimitrijević, S.,& Trumić, B.. (2015). MASS SPECTROMETRY FOR STRUCTURAL CHARACTERIZATION OF NON-CYANIDE GOLD COMPLEX. in Proceedings / 47th International October Conference on Mining and Metallurgy - IOC 2015, 4th-6th October 2015, Bor Lake, Serbia
Bor : Mining and Metallurgy Institute., 379-386.
https://hdl.handle.net/21.15107/rcub_technorep_7003

Dimitrijević S, Milošević M, Veličković S, Alagić S, Rajčić-Vujasinović M, Dimitrijević S, Trumić B. MASS SPECTROMETRY FOR STRUCTURAL CHARACTERIZATION OF NON-CYANIDE GOLD COMPLEX. in Proceedings / 47th International October Conference on Mining and Metallurgy - IOC 2015, 4th-6th October 2015, Bor Lake, Serbia. 2015;:379-386.
https://hdl.handle.net/21.15107/rcub_technorep_7003 .

Dimitrijević, Silvana, Milošević, Maja, Veličković, Suzana, Alagić, Slađana, Rajčić-Vujasinović, Mirjana, Dimitrijević, Stevan, Trumić, Biserka, "MASS SPECTROMETRY FOR STRUCTURAL CHARACTERIZATION OF NON-CYANIDE GOLD COMPLEX" in Proceedings / 47th International October Conference on Mining and Metallurgy - IOC 2015, 4th-6th October 2015, Bor Lake, Serbia (2015):379-386,
https://hdl.handle.net/21.15107/rcub_technorep_7003 .

TY  - JOUR
AU  - Veljković, Filip M.
AU  - Đustebek, Jasmina B.
AU  - Veljković, Miomir V.
AU  - Veličković, Suzana
AU  - Perić-Grujić, Aleksandra
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2140
AB  - RATIONALE The very small clusters of the type KnF are of particular importance since their first ionization energies (IEs) are lower than those of the alkali metal atoms. Theoretical calculation has demonstrated that this kind of cluster represents a potential 'building block' for cluster-assembly materials with unique structural, electronic, optical, magnetic, and thermodynamic properties. To date, however, there have been no experimental results on the IEs of KnF (n  gt 2) clusters. METHOD KnF (n?=?26) clusters were produced by the evaporation of a solid potassium fluoride salt using a modified thermal ionization source of modified design, and mass selected by a magnetic sector mass spectrometer where their IEs were determined. RESULTS Clusters KnF (n?=?36) were detected for the first time. The order of the ion intensities was K2F+ gt ? gt ?K4F+ gt ? gt ?K3F+K6F+? gt ?K5F+. The determined IEs were 3.99 +/- 0.20?eV for K2F, 4.16 +/- 0.20?eV for K3F, 4.27 +/- 0.20?eV for K4F, 4.22 +/- 0.20?eV for K5F, and 4.31 +/- 0.20?eV for K6F. The IEs of KnF increase slightly with the increase in potassium atom number from 2 to 6. We also observed that the presence of a fluorine atom leads to increasing ionization energy of bare metal potassium clusters. CONCLUSIONS The modified thermal ionization source provides an efficient way of obtaining the fluorine-doped potassium clusters. These results also present experimental proof that KnF (n?=?26) clusters belong to the group of 'superalkali' species.
PB  - Wiley, Hoboken
T2  - Rapid Communications in Mass Spectrometry
T1  - Production and ionization energies of KnF (n=2-6) clusters by thermal ionization mass spectrometry
EP  - 1766
IS  - 16
SP  - 1761
VL  - 26
DO  - 10.1002/rcm.6284
ER  - 

@article{
author = "Veljković, Filip M. and Đustebek, Jasmina B. and Veljković, Miomir V. and Veličković, Suzana and Perić-Grujić, Aleksandra",
year = "2012",
abstract = "RATIONALE The very small clusters of the type KnF are of particular importance since their first ionization energies (IEs) are lower than those of the alkali metal atoms. Theoretical calculation has demonstrated that this kind of cluster represents a potential 'building block' for cluster-assembly materials with unique structural, electronic, optical, magnetic, and thermodynamic properties. To date, however, there have been no experimental results on the IEs of KnF (n  gt 2) clusters. METHOD KnF (n?=?26) clusters were produced by the evaporation of a solid potassium fluoride salt using a modified thermal ionization source of modified design, and mass selected by a magnetic sector mass spectrometer where their IEs were determined. RESULTS Clusters KnF (n?=?36) were detected for the first time. The order of the ion intensities was K2F+ gt ? gt ?K4F+ gt ? gt ?K3F+K6F+? gt ?K5F+. The determined IEs were 3.99 +/- 0.20?eV for K2F, 4.16 +/- 0.20?eV for K3F, 4.27 +/- 0.20?eV for K4F, 4.22 +/- 0.20?eV for K5F, and 4.31 +/- 0.20?eV for K6F. The IEs of KnF increase slightly with the increase in potassium atom number from 2 to 6. We also observed that the presence of a fluorine atom leads to increasing ionization energy of bare metal potassium clusters. CONCLUSIONS The modified thermal ionization source provides an efficient way of obtaining the fluorine-doped potassium clusters. These results also present experimental proof that KnF (n?=?26) clusters belong to the group of 'superalkali' species.",
publisher = "Wiley, Hoboken",
journal = "Rapid Communications in Mass Spectrometry",
title = "Production and ionization energies of KnF (n=2-6) clusters by thermal ionization mass spectrometry",
pages = "1766-1761",
number = "16",
volume = "26",
doi = "10.1002/rcm.6284"
}

Veljković, F. M., Đustebek, J. B., Veljković, M. V., Veličković, S.,& Perić-Grujić, A.. (2012). Production and ionization energies of KnF (n=2-6) clusters by thermal ionization mass spectrometry. in Rapid Communications in Mass Spectrometry
Wiley, Hoboken., 26(16), 1761-1766.
https://doi.org/10.1002/rcm.6284

Veljković FM, Đustebek JB, Veljković MV, Veličković S, Perić-Grujić A. Production and ionization energies of KnF (n=2-6) clusters by thermal ionization mass spectrometry. in Rapid Communications in Mass Spectrometry. 2012;26(16):1761-1766.
doi:10.1002/rcm.6284 .

Veljković, Filip M., Đustebek, Jasmina B., Veljković, Miomir V., Veličković, Suzana, Perić-Grujić, Aleksandra, "Production and ionization energies of KnF (n=2-6) clusters by thermal ionization mass spectrometry" in Rapid Communications in Mass Spectrometry, 26, no. 16 (2012):1761-1766,
https://doi.org/10.1002/rcm.6284 . .

TY  - JOUR
AU  - Veljković, Filip M.
AU  - Đustebek, Jasmina B.
AU  - Veljković, Miomir V.
AU  - Perić-Grujić, Aleksandra
AU  - Veličković, Suzana
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2122
AB  - The theoretical calculations have predicted that nonmetal-doped potassium clusters can be used in the synthesis of a new class of charge-transfer salts which can be considered as potential building blocks for the assembly of novel nanostructured material. In this work, KnCl (n?=?26) and KnCln-1 (n?=?3 and 4) clusters were produced by vaporization of a solid potassium chloride salt in a thermal ionization mass spectrometry. The ionization energies (IEs) were measured, and found to be 3.64?+/-?0.20?eV for K2Cl, 3.67?+/-?0.20?eV for K3Cl, 3.62?+/-?0.20?eV for K4Cl, 3.57?+/-?0.20?eV for K5Cl, 3.69?+/-?0.20?eV for K6Cl, 3.71?+/-?0.20?eV for K3Cl2 and 3.72?+/-?0.20?eV for K4Cl3. The KnCl+ (n?=?36) clusters were detected for the first time in a cluster beam generated by the thermal ionization source of modified design. Also, this work is the first to report experimentally obtained values of IEs for KnCl+ (n?=?36) and KnCln-1+ (n?=?3 and 4) clusters. The ionization energies for KnCl+ and KnCln-1+ clusters are much lower than the 4.34?eV of the potassium atom; hence, these clusters should be classified as superalkali species.
PB  - Wiley, Hoboken
T2  - Journal of Mass Spectrometry
T1  - Study of small chlorine-doped potassium clusters by thermal ionization mass spectrometry
EP  - 1499
IS  - 11
SP  - 1495
VL  - 47
DO  - 10.1002/jms.3076
ER  - 

@article{
author = "Veljković, Filip M. and Đustebek, Jasmina B. and Veljković, Miomir V. and Perić-Grujić, Aleksandra and Veličković, Suzana",
year = "2012",
abstract = "The theoretical calculations have predicted that nonmetal-doped potassium clusters can be used in the synthesis of a new class of charge-transfer salts which can be considered as potential building blocks for the assembly of novel nanostructured material. In this work, KnCl (n?=?26) and KnCln-1 (n?=?3 and 4) clusters were produced by vaporization of a solid potassium chloride salt in a thermal ionization mass spectrometry. The ionization energies (IEs) were measured, and found to be 3.64?+/-?0.20?eV for K2Cl, 3.67?+/-?0.20?eV for K3Cl, 3.62?+/-?0.20?eV for K4Cl, 3.57?+/-?0.20?eV for K5Cl, 3.69?+/-?0.20?eV for K6Cl, 3.71?+/-?0.20?eV for K3Cl2 and 3.72?+/-?0.20?eV for K4Cl3. The KnCl+ (n?=?36) clusters were detected for the first time in a cluster beam generated by the thermal ionization source of modified design. Also, this work is the first to report experimentally obtained values of IEs for KnCl+ (n?=?36) and KnCln-1+ (n?=?3 and 4) clusters. The ionization energies for KnCl+ and KnCln-1+ clusters are much lower than the 4.34?eV of the potassium atom; hence, these clusters should be classified as superalkali species.",
publisher = "Wiley, Hoboken",
journal = "Journal of Mass Spectrometry",
title = "Study of small chlorine-doped potassium clusters by thermal ionization mass spectrometry",
pages = "1499-1495",
number = "11",
volume = "47",
doi = "10.1002/jms.3076"
}

Veljković, F. M., Đustebek, J. B., Veljković, M. V., Perić-Grujić, A.,& Veličković, S.. (2012). Study of small chlorine-doped potassium clusters by thermal ionization mass spectrometry. in Journal of Mass Spectrometry
Wiley, Hoboken., 47(11), 1495-1499.
https://doi.org/10.1002/jms.3076

Veljković FM, Đustebek JB, Veljković MV, Perić-Grujić A, Veličković S. Study of small chlorine-doped potassium clusters by thermal ionization mass spectrometry. in Journal of Mass Spectrometry. 2012;47(11):1495-1499.
doi:10.1002/jms.3076 .

Veljković, Filip M., Đustebek, Jasmina B., Veljković, Miomir V., Perić-Grujić, Aleksandra, Veličković, Suzana, "Study of small chlorine-doped potassium clusters by thermal ionization mass spectrometry" in Journal of Mass Spectrometry, 47, no. 11 (2012):1495-1499,
https://doi.org/10.1002/jms.3076 . .

TY  - JOUR
AU  - Veličković, Suzana
AU  - Veljković, Filip M.
AU  - Perić-Grujić, Aleksandra
AU  - Radak, Bojan
AU  - Veljković, Miomir V.
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1859
AB  - The electronic structure and properties of dipotassiummonohalides are important for understanding the unique physical and chemical behavior of MnX systems. In the present study, K2X (here X=F, Cl, Br, I) clusters were generated in the vapor over salts of the corresponding potassium halide, using a magnetic sector thermal ionization mass spectrometer. The ionization energies obtained for K2F, K2Cl, K2Br, and K2I molecules were 3.82 +/- 0.1eV, 3.68 +/- 0.1eV, 3.95 +/- 0.1eV, and 3.92 +/- 0.1, respectively. These experimental values of ionization energies for K2X (X=F, Br, and I) are presented for the first time. The ionization energy of K2Cl determined by thermal ionization corresponds to previous results obtained by photoionization mass spectrometry, and it agrees with the theoretical ionization energy calculated by the ab initio method. The presently obtained results support previous theoretical predictions that the excess electron in dipotassiummonohalide clusters is delocalized over two potassium atoms, which is characteristic for F-center clusters.
PB  - Wiley, Hoboken
T2  - Rapid Communications in Mass Spectrometry
T1  - Ionization energies of K2X (X=F, Cl, Br, I) clusters
EP  - 2332
IS  - 16
SP  - 2327
VL  - 25
DO  - 10.1002/rcm.5128
ER  - 

@article{
author = "Veličković, Suzana and Veljković, Filip M. and Perić-Grujić, Aleksandra and Radak, Bojan and Veljković, Miomir V.",
year = "2011",
abstract = "The electronic structure and properties of dipotassiummonohalides are important for understanding the unique physical and chemical behavior of MnX systems. In the present study, K2X (here X=F, Cl, Br, I) clusters were generated in the vapor over salts of the corresponding potassium halide, using a magnetic sector thermal ionization mass spectrometer. The ionization energies obtained for K2F, K2Cl, K2Br, and K2I molecules were 3.82 +/- 0.1eV, 3.68 +/- 0.1eV, 3.95 +/- 0.1eV, and 3.92 +/- 0.1, respectively. These experimental values of ionization energies for K2X (X=F, Br, and I) are presented for the first time. The ionization energy of K2Cl determined by thermal ionization corresponds to previous results obtained by photoionization mass spectrometry, and it agrees with the theoretical ionization energy calculated by the ab initio method. The presently obtained results support previous theoretical predictions that the excess electron in dipotassiummonohalide clusters is delocalized over two potassium atoms, which is characteristic for F-center clusters.",
publisher = "Wiley, Hoboken",
journal = "Rapid Communications in Mass Spectrometry",
title = "Ionization energies of K2X (X=F, Cl, Br, I) clusters",
pages = "2332-2327",
number = "16",
volume = "25",
doi = "10.1002/rcm.5128"
}

Veličković, S., Veljković, F. M., Perić-Grujić, A., Radak, B.,& Veljković, M. V.. (2011). Ionization energies of K2X (X=F, Cl, Br, I) clusters. in Rapid Communications in Mass Spectrometry
Wiley, Hoboken., 25(16), 2327-2332.
https://doi.org/10.1002/rcm.5128

Veličković S, Veljković FM, Perić-Grujić A, Radak B, Veljković MV. Ionization energies of K2X (X=F, Cl, Br, I) clusters. in Rapid Communications in Mass Spectrometry. 2011;25(16):2327-2332.
doi:10.1002/rcm.5128 .

Veličković, Suzana, Veljković, Filip M., Perić-Grujić, Aleksandra, Radak, Bojan, Veljković, Miomir V., "Ionization energies of K2X (X=F, Cl, Br, I) clusters" in Rapid Communications in Mass Spectrometry, 25, no. 16 (2011):2327-2332,
https://doi.org/10.1002/rcm.5128 . .

TY  - JOUR
AU  - Cvetićanin, Jelena M.
AU  - Veličković, Suzana
AU  - Đorđević, Vesna R.
AU  - Đustebek, Jasmina B.
AU  - Veljković, Miomir V.
AU  - Perić-Grujić, Aleksandra
AU  - Nešković, Olivera M.
PY  - 2008
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1322
AB  - Using the ion implantation technique (introducing negatively charged fullerene into a low temperature lithium plasma column by a strong axial magnetic field) endohedral fullerenes Li"C-70, Li-2"C-70 and Li-3"C-70 were produced. Mass spectral studies (both TIMS-thermal ionization mass spectrometry and MALDI TOF MS - matrix assisted laser desorption ionization time-of-flight mass spectrometry) of these endohedral fullerenes provided detailed structural and reactivity information about these unusual species. The fragmentation of the obtained ions is shown to be by a multiple C-2 loss (shrink-wrap mechanism). According to the fact that more atoms in the fullerene make the produced endohedral less stable, Li-3"C-70 shows a big degree of instability. The presence of Li-3"C-70 was observed on MALDI TOF MS.
PB  - Natl Inst Optoelectronics, Bucharest-Magurele
T2  - Journal of Optoelectronics and Advanced Materials
T1  - TIMS and MALDI TOF of endohedral Li-n"C-70 (n=1-3) metallofullerenes
EP  - 1507
IS  - 6
SP  - 1505
VL  - 10
UR  - https://hdl.handle.net/21.15107/rcub_vinar_3472
ER  - 

@article{
author = "Cvetićanin, Jelena M. and Veličković, Suzana and Đorđević, Vesna R. and Đustebek, Jasmina B. and Veljković, Miomir V. and Perić-Grujić, Aleksandra and Nešković, Olivera M.",
year = "2008",
abstract = "Using the ion implantation technique (introducing negatively charged fullerene into a low temperature lithium plasma column by a strong axial magnetic field) endohedral fullerenes Li"C-70, Li-2"C-70 and Li-3"C-70 were produced. Mass spectral studies (both TIMS-thermal ionization mass spectrometry and MALDI TOF MS - matrix assisted laser desorption ionization time-of-flight mass spectrometry) of these endohedral fullerenes provided detailed structural and reactivity information about these unusual species. The fragmentation of the obtained ions is shown to be by a multiple C-2 loss (shrink-wrap mechanism). According to the fact that more atoms in the fullerene make the produced endohedral less stable, Li-3"C-70 shows a big degree of instability. The presence of Li-3"C-70 was observed on MALDI TOF MS.",
publisher = "Natl Inst Optoelectronics, Bucharest-Magurele",
journal = "Journal of Optoelectronics and Advanced Materials",
title = "TIMS and MALDI TOF of endohedral Li-n"C-70 (n=1-3) metallofullerenes",
pages = "1507-1505",
number = "6",
volume = "10",
url = "https://hdl.handle.net/21.15107/rcub_vinar_3472"
}

Cvetićanin, J. M., Veličković, S., Đorđević, V. R., Đustebek, J. B., Veljković, M. V., Perić-Grujić, A.,& Nešković, O. M.. (2008). TIMS and MALDI TOF of endohedral Li-n"C-70 (n=1-3) metallofullerenes. in Journal of Optoelectronics and Advanced Materials
Natl Inst Optoelectronics, Bucharest-Magurele., 10(6), 1505-1507.
https://hdl.handle.net/21.15107/rcub_vinar_3472

Cvetićanin JM, Veličković S, Đorđević VR, Đustebek JB, Veljković MV, Perić-Grujić A, Nešković OM. TIMS and MALDI TOF of endohedral Li-n"C-70 (n=1-3) metallofullerenes. in Journal of Optoelectronics and Advanced Materials. 2008;10(6):1505-1507.
https://hdl.handle.net/21.15107/rcub_vinar_3472 .

Cvetićanin, Jelena M., Veličković, Suzana, Đorđević, Vesna R., Đustebek, Jasmina B., Veljković, Miomir V., Perić-Grujić, Aleksandra, Nešković, Olivera M., "TIMS and MALDI TOF of endohedral Li-n"C-70 (n=1-3) metallofullerenes" in Journal of Optoelectronics and Advanced Materials, 10, no. 6 (2008):1505-1507,
https://hdl.handle.net/21.15107/rcub_vinar_3472 .

TY  - JOUR
AU  - Nešković, Olivera M.
AU  - Veljković, Miomir V.
AU  - Veličković, Suzana
AU  - Petkovska, LT
AU  - Perić-Grujić, Aleksandra
PY  - 2003
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/559
AB  - Ionization energies of hypervalent Li2F, Li2Cl and Na2Cl molecules detected by surface ionization electron impact neutralization mass spectrometry are reported. The ionization energies were 3.78 +/- 0.2 eV for Li2F, 4.93 +/- 0.2 eV for Li2Cl, and 4.21 +/- 0.2 eV for Na2Cl. The ionization energies (IE) agree with theoretical ionization energies calculated by ab initio methods,(1) supporting the theoretical prediction that Li2F has a hyperlithiated configuration in which the odd electron delocalizes over the two lithiums and with photoionization measurement.(2) The first ionization energy of Na2Cl was experimentally confirmed earlier(3-7) and for Li2Cl as well.(8) We have developed and used this new approach for the problem-in the present work ions were first formed by surface ionization, followed by electron attachment (neutralization).
PB  - John Wiley & Sons Ltd, W Sussex
T2  - Rapid Communications in Mass Spectrometry
T1  - Ionization energies of hypervalent Li2F, Li2Cl and Na2Cl molecules obtained by surface ionization electron impact neutralization mass spectrometry
EP  - 214
IS  - 3
SP  - 212
VL  - 17
DO  - 10.1002/rcm.896
ER  - 

@article{
author = "Nešković, Olivera M. and Veljković, Miomir V. and Veličković, Suzana and Petkovska, LT and Perić-Grujić, Aleksandra",
year = "2003",
abstract = "Ionization energies of hypervalent Li2F, Li2Cl and Na2Cl molecules detected by surface ionization electron impact neutralization mass spectrometry are reported. The ionization energies were 3.78 +/- 0.2 eV for Li2F, 4.93 +/- 0.2 eV for Li2Cl, and 4.21 +/- 0.2 eV for Na2Cl. The ionization energies (IE) agree with theoretical ionization energies calculated by ab initio methods,(1) supporting the theoretical prediction that Li2F has a hyperlithiated configuration in which the odd electron delocalizes over the two lithiums and with photoionization measurement.(2) The first ionization energy of Na2Cl was experimentally confirmed earlier(3-7) and for Li2Cl as well.(8) We have developed and used this new approach for the problem-in the present work ions were first formed by surface ionization, followed by electron attachment (neutralization).",
publisher = "John Wiley & Sons Ltd, W Sussex",
journal = "Rapid Communications in Mass Spectrometry",
title = "Ionization energies of hypervalent Li2F, Li2Cl and Na2Cl molecules obtained by surface ionization electron impact neutralization mass spectrometry",
pages = "214-212",
number = "3",
volume = "17",
doi = "10.1002/rcm.896"
}

Nešković, O. M., Veljković, M. V., Veličković, S., Petkovska, L.,& Perić-Grujić, A.. (2003). Ionization energies of hypervalent Li2F, Li2Cl and Na2Cl molecules obtained by surface ionization electron impact neutralization mass spectrometry. in Rapid Communications in Mass Spectrometry
John Wiley & Sons Ltd, W Sussex., 17(3), 212-214.
https://doi.org/10.1002/rcm.896

Nešković OM, Veljković MV, Veličković S, Petkovska L, Perić-Grujić A. Ionization energies of hypervalent Li2F, Li2Cl and Na2Cl molecules obtained by surface ionization electron impact neutralization mass spectrometry. in Rapid Communications in Mass Spectrometry. 2003;17(3):212-214.
doi:10.1002/rcm.896 .

Nešković, Olivera M., Veljković, Miomir V., Veličković, Suzana, Petkovska, LT, Perić-Grujić, Aleksandra, "Ionization energies of hypervalent Li2F, Li2Cl and Na2Cl molecules obtained by surface ionization electron impact neutralization mass spectrometry" in Rapid Communications in Mass Spectrometry, 17, no. 3 (2003):212-214,
https://doi.org/10.1002/rcm.896 . .