Bojan Soptrajanov | Ss. Cyril and Methodius University (UKIM) (Univerzitet "Sv. Kiril i Metodij" - Skopje) (original) (raw)
Papers by Bojan Soptrajanov
Journal of Molecular Structure, 1997
The FTIR spectra of the three title compounds and of their partially deuterated analogues were re... more The FTIR spectra of the three title compounds and of their partially deuterated analogues were recorded at both room and liquid-nitrogen temperature. As a consequence of the Jahn-Teller effect, the bands in the OH stretching region of the spectrum of Cu(BS)2·6H2O (BS = benzenesulphonate) are broad and split into at least two components which appear at somewhat higher and lower
Journal of Molecular Structure, 2001
ABSTRACT In the course of vibrational spectroscopic investigations of DNA–metal interactions, the... more ABSTRACT In the course of vibrational spectroscopic investigations of DNA–metal interactions, the FTIR spectra of protiated and iminodeuterated solid tetrakis(imidazole)copper(II) acetate were recorded at room temperature and the boiling temperature of liquid nitrogen (RT and LNT, respectively) and studied together with its RT Raman spectrum. Bands due to the internal vibrations of the acetate groups and imidazole ligands, are assigned and correlated with the available structural data.
Journal of Molecular Structure, 1992
ABSTRACT Two bands of unequal intensity and half-width are found in the OD stretching region of ... more ABSTRACT Two bands of unequal intensity and half-width are found in the OD stretching region of the room-temperature spectra of slightly deuterated ammonium 4-methyl-benzenesulfonate. The bond at higher frequencies is broader and more intense than that having a lower frequency value. Such a spectral picture suggests an effective symmetry of the NH3D+ ions not much different from the ideal C3v one, despite the fact that the site symmetry of the ammonium ions in the structure is only C1. Within each NH3D+ ion, the proton participating in the formation of the strongest hydrogen bond seems to be unique, whereas the remaining three are essentially equivalent, perhaps because of the rapid reorientation of the ions in the structure. The spectroscopic picture is not consistent with the published crystallographic data.An ammonium ion librational band is found in the low-temperature spectra (around 430 cm−1).
Journal of Molecular Structure, 2009
As a part of our vibrational spectroscopic investigations of crystalline hydrates of salts of mal... more As a part of our vibrational spectroscopic investigations of crystalline hydrates of salts of malonic acid, the FT-IR spectra of the dihydrates of four metal(II) malonates were recorded at room temperature (RT) and the boiling temperature of liquid nitrogen (LNT) and studied together with their RT Raman spectra. The regions of the OCO stretchings are discussed in more detail, and the appearance of the characteristic bands is correlated with the available structural data.
Spectroscopy Letters, 1968
Higher Education in Europe, 1991
Higher Education Policy, 1991
Acta Chimica Slovenica, 2008
Spectroscopy Letters, 1992
ABSTRACT
PRudarsko-geološki fakultet, Štip, Republika Makedonija A b s t r a c t: A review of the results ... more PRudarsko-geološki fakultet, Štip, Republika Makedonija A b s t r a c t: A review of the results of complementary use of vibrational spectroscopy (infrared and Raman) and powder X-ray diffraction in the process of identification and detection of some carbonate, sulfide, oxide and silicate minerals originating from the Republic of Macedonia is presented. Studied are the following minerals:
J Mol Struct, 2000
ABSTRACT Very low H–O–H bending frequencies (appreciably lower than that in gaseous water) have b... more ABSTRACT Very low H–O–H bending frequencies (appreciably lower than that in gaseous water) have been observed in the infrared spectra of several compounds of the MKPO4·H2O type. Thus, in the case of NiKPO4·H2O the only intense band attributable to the H–O–H bending appears at 1478 cm−1, whereas in the case of the magnesium compound the corresponding frequency is 1470 cm−1. A tentative explanation (supported by quantum chemical calculations) for this unusual phenomenon has been offered.
Educacion Quimica, 2009
Información del artículo "Modernization" of the Chemistry education process: do people ... more Información del artículo "Modernization" of the Chemistry education process: do people still perform real experiments?
Acta Chimica Slovenica, Dec 9, 2008
J Mol Struct, 2000
Fourier transform infrared spectra of indole in carbon tetrachloride solutions were recorded. The... more Fourier transform infrared spectra of indole in carbon tetrachloride solutions were recorded. The spectroscopic data indicate that even at relatively low concentrations, the solute forms molecularly associated pairs through N-Hctdotπ hydrogen bonding. Both NIR data and AM1 calculations show that, in comparison with the monomeric ν(N-H) mode, the anharmonicity of the ν(N-Hctdotπ) mode decreases, and that of the dimeric ν(N-H) mode slightly increases. The anharmonicity constants for these modes are calculated on the basis of the NIR data, and the changes of the ν(N-H) potential upon N-Hctdotπ hydrogen bonding are quantitatively studied. The orientational dynamics of monomeric and associated indole species are studied within the framework of the time correlation function formalism. The period of essentially free rotation in the condensed phase reduces from 2.3 ps for the monomeric indole to 0.4 ps for the proton-donor molecule within the dimer.
J Mol Struct, 2004
The discrepancy between the infrared data in the region of the O-D stretching vibrations and the ... more The discrepancy between the infrared data in the region of the O-D stretching vibrations and the proposed centrosymmetric space group Immm for tricesium trans-tetra-aquadichlorovanadium(III) tetrachloride, Cs 3[VCl 2(H 2O) 4]Cl 4, was the reason behind our decision to redetermine the crystal structure of this compound and refine it in the non-centrosymmetric space group I222. Crystal data: Cs 3VCl 6·4H 2O, orthorhombic, I222, a=8.346(1), b=17.646(2), c=6.044(1) Å, V=890.1(2) Å 3, Z=2. The water molecules were found to occupy general positions, each of them forming two non-equivalent hydrogen bonds of the O wctdotCl type (3.032 and 3.043 Å). These structural data agree well with the appearance of two bands in the O-D stretching region of the infrared spectrum of the isotopically isolated HOD molecules.
A b s t rae t : The appearance of the VI mode (1083 em I) in the Ff IR spectrum of aragonite (abs... more A b s t rae t : The appearance of the VI mode (1083 em I) in the Ff IR spectrum of aragonite (absent in the spectrum of calcite) as well as the lower frequency of the V4 mode in the spectrum of aragonite (713 and 700 emI) than in that of calcite (732 emI) made it possible to detect the presence of aragonite in calcite and to determine its content. Similarly, the higher frequency of the V4 mode in the spectrum of calcite (732 emI) than in aragonite (713 and 700 em I) was used to detect impurities as well as to determine the content of calcite in aragonite.
Acta Chimica Slovenica, Sep 1, 2011
The infrared and Raman spectra of magnesium rubidium phosphate hexahydrate MgRbPO 4 · 6H 2 O and ... more The infrared and Raman spectra of magnesium rubidium phosphate hexahydrate MgRbPO 4 · 6H 2 O and magnesium thallium phosphate hexahydrate, MgTlPO 4 · 6H 2 O were recorded at room temperature (RT) and the boiling temperature of liquid nitrogen (LNT). To facilitate their analysis, also recorded were the spectra of partially deuterated analogues with varying content of deuterium. The effects of deuteration and those of lowering the temperature were the basis of the conclusions drawn regarding the origin of the observed bands which were assigned to vibrations which are predominantly localized in the water molecules (four crystallographically different types of such molecules exist in the structures) and those with PO 4 3character. It was concluded that in some cases coupling of phosphate and water vibrations is likely to take place. The appearance of the infrared spectra in the O-H stretching regions of the infrared spectra is explained as being the result of an extensive overlap of bands due to components of the fundamental stretching modes of the H 2 O units with a possible participation of bands due to second-order transitions. A broad band reminiscent of the B band of the well-known ABC trio characteristic of spectra of substances containing strong hydrogen bonds in their structure was found around 2400 cm -1 in the infrared spectra of the two studied compounds.
Macedonian Journal of Chemistry and Chemical Engineering, May 19, 2008
ja~ini, {to doveduva do prepokrivawe na soodvetnite lenti vo spektarot. Nasproti postoeweto, vo s... more ja~ini, {to doveduva do prepokrivawe na soodvetnite lenti vo spektarot. Nasproti postoeweto, vo strukturata na ova soedinenie, na dve karbonilni grupi so mnogu bliski C-O rastojanija [124.2(3) i 124.0(3) pm], vo infracrveniot spektar (1660 i 1627 cm -1 ) i vo ramanskiot spektar (1648 i 1620 cm -1 ) se registrirani po dve jasno razdvoeni lenti vo podra~jeto na karbonilnite valentni vibracii. Od druga strana, i pokraj postoeweto na dve neekvivalentni SO 2 -grupi vo strukturata na Mg(sac) 2 ⋅7H 2 O, infracrveniot spektar vo podra~jeto na SO 2 -valentnite vibracii [ν as (SO 2 i ν s (SO 2 ) modovi] se pojavuva samo eden par lenti. Klu~ni zborovi: magnezium disaharinat heptahidrat; infracrven spektar; ramanski spektar; spektar-strukturni korelacii
Spectroscopy Letters, Oct 1, 1995
ABSTRACT The infrared spectra of a series of metal saccharinates (those of Na, Mg, Mn Fe, Co; Ni,... more ABSTRACT The infrared spectra of a series of metal saccharinates (those of Na, Mg, Mn Fe, Co; Ni, Zn, Cd, Pb as well as mercury(II) saccharinate and chloromercury(II) saccharinate) were studied in the region of the antisymmetric and symmetric SO2 stretching vibrations [vas(SO2) and vs(SO2) hereafter]. The results concerning the number of bands attributable to the abovementioned vibrations, their frequencies and intensities were correlated with the crystallographically determined type of metal-to-ligand bonding, on the one hand, and the number of the structurally different SO2 groups, on the other.
Neues Jahrbuch Fur Mineralogie Abhandlungen, Jul 31, 2002
The use of FTIR spectroscopy to distinguish between some geologically important carbonate mineral... more The use of FTIR spectroscopy to distinguish between some geologically important carbonate minerals (calcite -CaCO 3 , aragonite -CaCO 3 , siderite -FeCO 3 , magnesite -MgCO 3 and dolomite -CaMg(CO 3 ) 2 ) originating from Macedonia and to detect mineral impurities in them is considered. It was shown that the series of the studied isomorphous calcite type minerals is an ideal test case for the evaluating the influence of the corresponding cation upon the band frequencies of the carbonate n 3 , n 2 and n 4 modes in their infrared spectra. It enables to distinguish the isomorphous calcite type carbonates from one another. In the course of the quantitative determination of the composition of mixtures it is shown that the limit of detection of impurities of aragonite in the mixtures with calcite (or other calcite type minerals) is around 1 wt %. The spectra of natural calcite and siderite were compared to those of their synthetic analogues.
Journal of Molecular Structure, 1997
The FTIR spectra of the three title compounds and of their partially deuterated analogues were re... more The FTIR spectra of the three title compounds and of their partially deuterated analogues were recorded at both room and liquid-nitrogen temperature. As a consequence of the Jahn-Teller effect, the bands in the OH stretching region of the spectrum of Cu(BS)2·6H2O (BS = benzenesulphonate) are broad and split into at least two components which appear at somewhat higher and lower
Journal of Molecular Structure, 2001
ABSTRACT In the course of vibrational spectroscopic investigations of DNA–metal interactions, the... more ABSTRACT In the course of vibrational spectroscopic investigations of DNA–metal interactions, the FTIR spectra of protiated and iminodeuterated solid tetrakis(imidazole)copper(II) acetate were recorded at room temperature and the boiling temperature of liquid nitrogen (RT and LNT, respectively) and studied together with its RT Raman spectrum. Bands due to the internal vibrations of the acetate groups and imidazole ligands, are assigned and correlated with the available structural data.
Journal of Molecular Structure, 1992
ABSTRACT Two bands of unequal intensity and half-width are found in the OD stretching region of ... more ABSTRACT Two bands of unequal intensity and half-width are found in the OD stretching region of the room-temperature spectra of slightly deuterated ammonium 4-methyl-benzenesulfonate. The bond at higher frequencies is broader and more intense than that having a lower frequency value. Such a spectral picture suggests an effective symmetry of the NH3D+ ions not much different from the ideal C3v one, despite the fact that the site symmetry of the ammonium ions in the structure is only C1. Within each NH3D+ ion, the proton participating in the formation of the strongest hydrogen bond seems to be unique, whereas the remaining three are essentially equivalent, perhaps because of the rapid reorientation of the ions in the structure. The spectroscopic picture is not consistent with the published crystallographic data.An ammonium ion librational band is found in the low-temperature spectra (around 430 cm−1).
Journal of Molecular Structure, 2009
As a part of our vibrational spectroscopic investigations of crystalline hydrates of salts of mal... more As a part of our vibrational spectroscopic investigations of crystalline hydrates of salts of malonic acid, the FT-IR spectra of the dihydrates of four metal(II) malonates were recorded at room temperature (RT) and the boiling temperature of liquid nitrogen (LNT) and studied together with their RT Raman spectra. The regions of the OCO stretchings are discussed in more detail, and the appearance of the characteristic bands is correlated with the available structural data.
Spectroscopy Letters, 1968
Higher Education in Europe, 1991
Higher Education Policy, 1991
Acta Chimica Slovenica, 2008
Spectroscopy Letters, 1992
ABSTRACT
PRudarsko-geološki fakultet, Štip, Republika Makedonija A b s t r a c t: A review of the results ... more PRudarsko-geološki fakultet, Štip, Republika Makedonija A b s t r a c t: A review of the results of complementary use of vibrational spectroscopy (infrared and Raman) and powder X-ray diffraction in the process of identification and detection of some carbonate, sulfide, oxide and silicate minerals originating from the Republic of Macedonia is presented. Studied are the following minerals:
J Mol Struct, 2000
ABSTRACT Very low H–O–H bending frequencies (appreciably lower than that in gaseous water) have b... more ABSTRACT Very low H–O–H bending frequencies (appreciably lower than that in gaseous water) have been observed in the infrared spectra of several compounds of the MKPO4·H2O type. Thus, in the case of NiKPO4·H2O the only intense band attributable to the H–O–H bending appears at 1478 cm−1, whereas in the case of the magnesium compound the corresponding frequency is 1470 cm−1. A tentative explanation (supported by quantum chemical calculations) for this unusual phenomenon has been offered.
Educacion Quimica, 2009
Información del artículo "Modernization" of the Chemistry education process: do people ... more Información del artículo "Modernization" of the Chemistry education process: do people still perform real experiments?
Acta Chimica Slovenica, Dec 9, 2008
J Mol Struct, 2000
Fourier transform infrared spectra of indole in carbon tetrachloride solutions were recorded. The... more Fourier transform infrared spectra of indole in carbon tetrachloride solutions were recorded. The spectroscopic data indicate that even at relatively low concentrations, the solute forms molecularly associated pairs through N-Hctdotπ hydrogen bonding. Both NIR data and AM1 calculations show that, in comparison with the monomeric ν(N-H) mode, the anharmonicity of the ν(N-Hctdotπ) mode decreases, and that of the dimeric ν(N-H) mode slightly increases. The anharmonicity constants for these modes are calculated on the basis of the NIR data, and the changes of the ν(N-H) potential upon N-Hctdotπ hydrogen bonding are quantitatively studied. The orientational dynamics of monomeric and associated indole species are studied within the framework of the time correlation function formalism. The period of essentially free rotation in the condensed phase reduces from 2.3 ps for the monomeric indole to 0.4 ps for the proton-donor molecule within the dimer.
J Mol Struct, 2004
The discrepancy between the infrared data in the region of the O-D stretching vibrations and the ... more The discrepancy between the infrared data in the region of the O-D stretching vibrations and the proposed centrosymmetric space group Immm for tricesium trans-tetra-aquadichlorovanadium(III) tetrachloride, Cs 3[VCl 2(H 2O) 4]Cl 4, was the reason behind our decision to redetermine the crystal structure of this compound and refine it in the non-centrosymmetric space group I222. Crystal data: Cs 3VCl 6·4H 2O, orthorhombic, I222, a=8.346(1), b=17.646(2), c=6.044(1) Å, V=890.1(2) Å 3, Z=2. The water molecules were found to occupy general positions, each of them forming two non-equivalent hydrogen bonds of the O wctdotCl type (3.032 and 3.043 Å). These structural data agree well with the appearance of two bands in the O-D stretching region of the infrared spectrum of the isotopically isolated HOD molecules.
A b s t rae t : The appearance of the VI mode (1083 em I) in the Ff IR spectrum of aragonite (abs... more A b s t rae t : The appearance of the VI mode (1083 em I) in the Ff IR spectrum of aragonite (absent in the spectrum of calcite) as well as the lower frequency of the V4 mode in the spectrum of aragonite (713 and 700 emI) than in that of calcite (732 emI) made it possible to detect the presence of aragonite in calcite and to determine its content. Similarly, the higher frequency of the V4 mode in the spectrum of calcite (732 emI) than in aragonite (713 and 700 em I) was used to detect impurities as well as to determine the content of calcite in aragonite.
Acta Chimica Slovenica, Sep 1, 2011
The infrared and Raman spectra of magnesium rubidium phosphate hexahydrate MgRbPO 4 · 6H 2 O and ... more The infrared and Raman spectra of magnesium rubidium phosphate hexahydrate MgRbPO 4 · 6H 2 O and magnesium thallium phosphate hexahydrate, MgTlPO 4 · 6H 2 O were recorded at room temperature (RT) and the boiling temperature of liquid nitrogen (LNT). To facilitate their analysis, also recorded were the spectra of partially deuterated analogues with varying content of deuterium. The effects of deuteration and those of lowering the temperature were the basis of the conclusions drawn regarding the origin of the observed bands which were assigned to vibrations which are predominantly localized in the water molecules (four crystallographically different types of such molecules exist in the structures) and those with PO 4 3character. It was concluded that in some cases coupling of phosphate and water vibrations is likely to take place. The appearance of the infrared spectra in the O-H stretching regions of the infrared spectra is explained as being the result of an extensive overlap of bands due to components of the fundamental stretching modes of the H 2 O units with a possible participation of bands due to second-order transitions. A broad band reminiscent of the B band of the well-known ABC trio characteristic of spectra of substances containing strong hydrogen bonds in their structure was found around 2400 cm -1 in the infrared spectra of the two studied compounds.
Macedonian Journal of Chemistry and Chemical Engineering, May 19, 2008
ja~ini, {to doveduva do prepokrivawe na soodvetnite lenti vo spektarot. Nasproti postoeweto, vo s... more ja~ini, {to doveduva do prepokrivawe na soodvetnite lenti vo spektarot. Nasproti postoeweto, vo strukturata na ova soedinenie, na dve karbonilni grupi so mnogu bliski C-O rastojanija [124.2(3) i 124.0(3) pm], vo infracrveniot spektar (1660 i 1627 cm -1 ) i vo ramanskiot spektar (1648 i 1620 cm -1 ) se registrirani po dve jasno razdvoeni lenti vo podra~jeto na karbonilnite valentni vibracii. Od druga strana, i pokraj postoeweto na dve neekvivalentni SO 2 -grupi vo strukturata na Mg(sac) 2 ⋅7H 2 O, infracrveniot spektar vo podra~jeto na SO 2 -valentnite vibracii [ν as (SO 2 i ν s (SO 2 ) modovi] se pojavuva samo eden par lenti. Klu~ni zborovi: magnezium disaharinat heptahidrat; infracrven spektar; ramanski spektar; spektar-strukturni korelacii
Spectroscopy Letters, Oct 1, 1995
ABSTRACT The infrared spectra of a series of metal saccharinates (those of Na, Mg, Mn Fe, Co; Ni,... more ABSTRACT The infrared spectra of a series of metal saccharinates (those of Na, Mg, Mn Fe, Co; Ni, Zn, Cd, Pb as well as mercury(II) saccharinate and chloromercury(II) saccharinate) were studied in the region of the antisymmetric and symmetric SO2 stretching vibrations [vas(SO2) and vs(SO2) hereafter]. The results concerning the number of bands attributable to the abovementioned vibrations, their frequencies and intensities were correlated with the crystallographically determined type of metal-to-ligand bonding, on the one hand, and the number of the structurally different SO2 groups, on the other.
Neues Jahrbuch Fur Mineralogie Abhandlungen, Jul 31, 2002
The use of FTIR spectroscopy to distinguish between some geologically important carbonate mineral... more The use of FTIR spectroscopy to distinguish between some geologically important carbonate minerals (calcite -CaCO 3 , aragonite -CaCO 3 , siderite -FeCO 3 , magnesite -MgCO 3 and dolomite -CaMg(CO 3 ) 2 ) originating from Macedonia and to detect mineral impurities in them is considered. It was shown that the series of the studied isomorphous calcite type minerals is an ideal test case for the evaluating the influence of the corresponding cation upon the band frequencies of the carbonate n 3 , n 2 and n 4 modes in their infrared spectra. It enables to distinguish the isomorphous calcite type carbonates from one another. In the course of the quantitative determination of the composition of mixtures it is shown that the limit of detection of impurities of aragonite in the mixtures with calcite (or other calcite type minerals) is around 1 wt %. The spectra of natural calcite and siderite were compared to those of their synthetic analogues.