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Study of the 1,4-dihydroxyanthraquinone-yttrium(III) complex in solution and in the solid state
MICROCHEMICAL
34, 270-276 (1986)
JOURNAL
Study of the 1,4-Dihydroxyanthraquinone-Yttrium(lII) in Solution and in the Solid State M. RoMAN,A. Department
Complex
FERN~~NDEZ-GUTI~~RREZ,~ J. SUAREZ, AND F. ALI%
of General
Chemistry, 18071
Faculty Granada,
of Sciences, Spain
University
of Granada,
Received April 23, 1986; accepted June 12, 1986 The photometric and fluorometric characteristics of the complex formed by l,Cdihydroxyanthraquinone with Y(M) in 20-80% water-ethanol solution are described by the study of several variables. The stoichiometry and stability constant of the complex in the solution are 1:l and log K = 4.57, respectively. The 1,4-dihydroxyanthraquinone-Y(II1) solid complex has been prepared and studied by infrared spectroscopy and thermal analysis. The thermal behavior of this compound has been studied using thermogravimetry and differential scanning calorimetry techniques and the residue verified by X-ray diffraction. 8 1986 Academic Press. Inc.
INTRODUCTION
As the lanthanides, the Y(II1) forms stable binary complexes with organic ligands which have donor groups O,O, for instance, hydroxyflavonas, aluminon, hematoxiline, salycilic acid, hydroxyanthraquinones, etc. It also forms these complexes with some reagents which act as ligands with donor atoms 0,N. Examples of this last case are g-hydroxyquinoline, glyoxal bis(Zhydroxyanil), arsenazo I, toron, clorophosphonazo PN, etc. In general, the above complexes present, in solution, colorations which make possible their spectrophotometric study. In some cases the luminescence also appears and this can be imputed to the organic part of the complex molecule and also to the absence of 4felectron in the Y(II1). Therefore, we are able to make the luminescent study of the organic reagent-Y(II1) complex. In the literature we find some interesting studies about the chemistry of coordination of the Y(II1) and other rare earth ions, the separation methods of Y(II1) and organic reagents, and appropriate methods for photometric and fluorimetric determination of Y(II1) (I, 3-5, 8-f I). The 1,4-dihydroxyanthraquinone or quinizarin (1,4-DHAn) forms in a waterethanol solution, a pink complex with Y(III), which is also fluorescent with apparent pH 4.5-6.7 (12). At pH higher than 6.7, provided by NH,OH, with an appropriate concentration of 1,4-DHAn and Y(III), a solid violet complex forms. In this paper the I,4-DHAn-Y(II1) complex is spectrophotometrically and spectrofluorometrically studied in water-ethanol solution and also in the solid state. ’ To whom correspondence
should be addressed. 270
0026-265X/86 $1 SO Copyright 6 1986 by Academic Press. Inc. All rights of reproduction in any form reserved.
I ,4-DIHYDROXYANTHRAQUINONE-YlTRIUM(II1)
MATERIALS
271
AND METHODS
Reagents. The chemicals used were of analytical grade. A lo-* M Y(II1) stock solution (deionized water) was prepared by weighing Y(NO,), * 5H,O and was standardized using the complexometric method. A solution of 10e3 M 1,4-DHAn (Merck R.A. recrystallized in ethanol) was prepared by weight and dissolved in ethanol. The other solution used in this study was prepared by dilution of these stock solutions. Apparatus. A Perkin-Elmer Model Lambda-5 spectrophotometer was used with cells of l-cm optical path length. Fluorescent measurements were carried out with a Perkin-Elmer MPF-43 spectrofluorometer with a thermostat cell holder for l-cm quartz cells. A Crison Model 501 pHmeter was used as well. Infrared spectra, in the region 4000-200 cm-i of sample in KBr pellets, were recorded using a Beckman 4250 spectrophotometer. Thermogravimetric studies on the isolated complex were carried out in a dynamic atmosphere of pure air (100 ml mini) on a Mettler TG 50 thermobalance with a heating rate of 10°C mini. The DSC curves were recorded on a Mettler differential scanning calorimeter (Model DSC-20) at a heating rate of 5°C min-’ in the temperature range of 35-550°C. The elemental analyses were performed on a Carlo Erba microanalyzer (Model 1106). Prepuration of the 1,4-DHAn- Y(ZZZ) solid complex. To 1.2 liters of low3 M ethanolic solution of 1,4-DHAn and at a temperature of 75”C, was added, slowly and shaking, 200 ml of 2 x lop3 M aqueous solution of Y(NO,), * 5H20. Afterward, 1 M NH,OH solution was slowly added, until an apparent pH 6.7 was reached. Then a blue-violet precipitate immediately occurred. After 1 hr the complex was filtered, washed with ethanol NH,OH mixtures, and vacuum-dried on H,SO, for several days. RESULTS
AND DISCUSSION
Spectrophotometric Study The ligand and cation concentrations used were 8 x lop5 M and the waterethanol relation was maintained constant at 20-80%, the study of the apparent pH influence on the complex absorption spectrum was accomplished by the addition of different concentrations of NH,OH. The complex shows an optimum formation with maximum absorption at apparent pH 5.7-67.0 (pink form, A,, = 525 and 560 nm) (Fig. 1). When the apparent pH is greater than 6.7 we are able to observe clearly the violet form (A,, = 535 nm) which precipitates as a solid complex in a few minutes. The ligand does not change its absorption spectrum in the studied interval of apparent pH (4.8-8.7). The water-ethanol relation in the medium affects the pink complex formation appreciably, the optimum relation of this being 20-80%. Under these conditions and with an apparent pH 5.8 fixed, it was verified that the complex solutions are stable in an hour’s time. The absorbance of complex solutions increase with the ligand concentration up to the ratio ligand:Y(III) of 6: 1, and then remains constant (measurements were made opposite a ligand solutions as blank). The plot of absorbance versus concentration of cation at 560 nm gave a straight line in the
272
ROMAN
ET AL.
0.7
0.5
0.3
al
150
500
550
600
650
Mnml
FIG. 1. Absorption pH = 8.5.
spectra. (I) Ligand; (2) complex, apparent pH = 5.8; (3) complex,
region of 1 to 7 ppm. This confirmed that the Lambert-Beer law was valid. For the molar absorptivity Ebb, a value of 12,000 liter bmol-km-l was found. The stoichiometry of 1,4-DHAn-Y(II1) complex in solution was studied by the continuous variations (Job) and the molar ratio (Yoe-Jones) methods. In both methods the stoichiometry was 1:l (Fig. 2). The formation constant calculation was realized applying the methods of Holme and Langmyhr (6), Roman ef al. (13, and by using Job’s plot (7). All methods gave similar values for the log K of 4.57.
0.9 I
x ‘\
/I0I .“-i /
I
,
0.5 -
I
\
\
.\\\ \\ \
1 02
0
0
J
i
0
0
0.1 19 a1
03
05
IYl11lO I [Ligandl FIG.
2. Job’s method. [Ligandl
+ [Y(lll)I
I
0.7
I
09
J
+CYIIIIlI
= 2 x 10e3 M. (1) A = 560 nm, (2) h = 525 nm.
1,4-DIHYDROXYANTHRAQUINONE-YTTRIUM(III)
Spectrojluorometric
273
Study
As our experiments have shown, the pink complex is fluorescent and the violet complex is not fluorescent. The excitation and emission spectra of the pink 1,4DHAn-Y(III) complex were registered with a solution 4 x low5 M in ligand and Y(M), in 20-80% water-ethanol medium at an apparent pH of 5.8. The complex shows two excitation maximums at 525 and 560 nm and emission maximum at 580 nm independent of the excitation wavelength. The ligand similarly treated presents more emission at 525 nm that at 560 nm (Fig. 3). In order to evaluate the effect of pH, this was changed in the apparent pH range 4.8-6.7 with NH,OH solution; at lower apparent pH there is no complex formation and at higher apparent pH the violet nonfluorescent complex is formed; the maximum fluorescent intensity was obtained for apparent pH 5.6-6.0. The study of the effect of water content in the medium show that the fluorescence is maximum for 20-30% water. To check the effect of other variables in the fluorescent properties of 1,4DHAn-Y(II1) complex, we fixed the following parameters: [Ligand] = [Y(M)] = 4 x lop5 M, apparent pH = 5.8, A,, = 560 nm, A,, = 580 nm, water-ethanol ratio = 20-80%; under these conditions we can observe that the complex is stable for an hour, the order of addition of reagent in the sample preparations have no influence on the result, and that the fluorescent intensity remains constant with the temperature between 14 and 26°C. The effect of ligand concentration was tested at a constant Y(II1) concentration of 4 x 1O-5 it4 by systematic variation of ligand concentration; the intensity of fluorescent emission of the complex was determined against a blank solution of the ligand. The results show a linear relationship between fluorescent intensity and ligand concentration up to 4 x 10e5 M. At higher ligand concentrations a quenching
Xlnm)
FIG.
(2) and
3. (1) Complex excitation A,, = 560 nm (2’). Ligand
spectrum, emission
A,, = 580 nm. Complex emission spectra, X,, = 525 nm spectra, h,, = 525 nm (3) and A,, = 560 nm (3’).
274
ROtiN
ET AL.
fluorescence by concentration is observed (Fig. 4). At a fixed ligand concent tion (4 x 10e5 M), the study of the influence of Y(II1) concentration on the co plex formation is carried out between 4 x 10e6 and 2.8 x 10s4 M Y(U), and t results show a linear relationship between fluorescent intensity and Y(II1) c( centration up to 4 x 1O-5 M (between 0.35 and 3.5 ppm). The methods of Yoe-Jones and Job for stoichiometry and the methods Roman er al. and Holme and Langmyhr for the formation constant calculati gave similar values by the spectrofluorometric as by spectrophotometric tee nique . Study of I ,4-DNAn-
Y(ZZZ)Solid Complex
The elemental analysis of the isolated complex, prepared as we previously dicated, was: C, 61.16; H, 2.33 (calculated for Y(C,, H,, Oi2); C, 62.54%; 2.62%. These results suggest that the solid complex presents a stoichiometry 3: 1, ligand:Y(III). The thermal behavior of this complex has been studied from their TG and D! diagrams (Fig. 5). It can be seen in these diagrams that water is not present because the saml was previously introduced in a dessicator with CaCl,. On the other hand, TG diagrams indicate that the complex is thermically stat up to 205°C; at this temperature the pyrolysis of the anthraquinone ring star This process takes place in two steps and finishes at 500°C and is responsible f the strong exothermic effect at 433°C in the DSC curve. The residue of the pyrolysis correspond to 13% of the initial sample weigl This value is in positive agreement to the theoretical value required for Y, (13.74%). The nature of the residue was corroborated from its powder X-ray d gram, which coincides with the card 5.574 (ICPDS) (2) for the cubic Y,C showing highest intensity at d = 3.05 w
I
5
FIG. 4. Effect of the amount of 1,4-DHAn. A,, = 560 nm, h,, = 580 nm, end vol. = 25 ml.
275
I .4-DIHYDROXYANTHRAQUINONE-YTTRIUM(II1) TEMPERATURE TEMPERATURE , .
OC
HEAT FLOW EXOTHERMAL 20.w ti
OC WEIGHT
GAIN
+
-
DTG
FIG. 5. TG and DSC diagrams for I,4-DHAn-Y(III).
There are two bands due to v(C=O), one of them (1590 cm-i) is not shifted with regard to the free ligand (1,4-dihydroxyanthraquinone), and the other one (1620 cm-i) corresponds to the C = 0 bonded to Y(Ci4H70& and is shifted to a lower wavenumber (10 cm-‘) with relation to the free ligand, this suggests the carbonyl group is coordinated with the metallic ion Y(II1). REFERENCES 1. Babko, A. K., Akhmedli, M. K., and Granovskaya, P. B., Photometric determination of yttrium subgroup rare earth elements. Uch. Zap. Azerb. Gos. Univ. Ser. Khim. Nauk 2, 48-52 (1970); Zh. Khim. 19GD, 3G80 (1971). 2. Berry, L. G., “Inorganic Index of Powder Diffraction File,” Published by J.C.P.D.S., Philadelphia, 1974. S. Busev, A. I., Tiptsova, V. G., and Ivanov, V. M., “Analytical Chemistry of Rare Element,” pp. 90-93. Mir Publisher, Moscow, 1981. 4. Eremin, Yu. G., and Bondarenko, G. I. Modern analytical methods for the determination and separation of yttrium. Zavod. Lab. 38, 796-801 (1972). 5. Fernandez-Gutierrez, A., and Mufioz de la Petia., Determination of Inorganic Substances by Luminiscence Methods. In “Molecular Luminiscence Spectroscopy” (S. G. Schulman, ed.), Part I, pp. 371-546. Wiley-Interscience, New York, 1985. 6. Holme, A., and Langmyhr, F. J., Modified straight-line method for determining the composition of weak complexes of the form A,B,. Anal. Chim. Acra 36, 383 (1966). 7. Meites, L., and Thomas, H. C., “Advances in Analytical Chemistry.” McGraw-Hill, New York, 1958. 8. Menkov, A. A., and Bocharova, R. I., Organic reagents for the spectrophotometric determination of yttrium. Fiz. Metody Issled. Anal. Biol. Ob’ektov Nekok. Tekh. Mater.. 43-50 (1971); Zh. Khim., 1972 Abstr. No 2G84. 9. Moeller, T., The coordination chemistry of yttrium and the rare earth metal ions. Chem. Rerf. 65, l-50 (1965).
276
ROMAN
ET AL.
10. Poluektov, N. S., Sandu, M. A., and Lauer, R. S., Comparative study of reagents for determining rare earth elements in a binary mixture. Zavod. Lab. 36, 1425-1428 (1970). II. Roman, M., Fernandez-Gutierrez, A., Gonzalez Garcia, D. V., and Marin, C., Determination fotometrica y fluorimetrica de Y(II1) Quim. Anal. 4, 23-38 (1985). 12. Roman, M., Femandez-Gutierrez, A., and Marin, C., Estudio espectrofluorimetrico y reaccionabilidad fluorescente de algunas hidroxiantraquinonas. Ajhidad 34, 481-486 (1977). 13. Roman, M., Mmioz Leyva, J. A., and Jimenez Sanchez, J. C. A new method for determining the composition and stability constant of complexes of the form A,B,. Anal. Chirn. ACM 90, 233-231 (1977).
34, 270-276 (1986)
JOURNAL
Study of the 1,4-Dihydroxyanthraquinone-Yttrium(lII) in Solution and in the Solid State M. RoMAN,A. Department
Complex
FERN~~NDEZ-GUTI~~RREZ,~ J. SUAREZ, AND F. ALI%
of General
Chemistry, 18071
Faculty Granada,
of Sciences, Spain
University
of Granada,
Received April 23, 1986; accepted June 12, 1986 The photometric and fluorometric characteristics of the complex formed by l,Cdihydroxyanthraquinone with Y(M) in 20-80% water-ethanol solution are described by the study of several variables. The stoichiometry and stability constant of the complex in the solution are 1:l and log K = 4.57, respectively. The 1,4-dihydroxyanthraquinone-Y(II1) solid complex has been prepared and studied by infrared spectroscopy and thermal analysis. The thermal behavior of this compound has been studied using thermogravimetry and differential scanning calorimetry techniques and the residue verified by X-ray diffraction. 8 1986 Academic Press. Inc.
INTRODUCTION
As the lanthanides, the Y(II1) forms stable binary complexes with organic ligands which have donor groups O,O, for instance, hydroxyflavonas, aluminon, hematoxiline, salycilic acid, hydroxyanthraquinones, etc. It also forms these complexes with some reagents which act as ligands with donor atoms 0,N. Examples of this last case are g-hydroxyquinoline, glyoxal bis(Zhydroxyanil), arsenazo I, toron, clorophosphonazo PN, etc. In general, the above complexes present, in solution, colorations which make possible their spectrophotometric study. In some cases the luminescence also appears and this can be imputed to the organic part of the complex molecule and also to the absence of 4felectron in the Y(II1). Therefore, we are able to make the luminescent study of the organic reagent-Y(II1) complex. In the literature we find some interesting studies about the chemistry of coordination of the Y(II1) and other rare earth ions, the separation methods of Y(II1) and organic reagents, and appropriate methods for photometric and fluorimetric determination of Y(II1) (I, 3-5, 8-f I). The 1,4-dihydroxyanthraquinone or quinizarin (1,4-DHAn) forms in a waterethanol solution, a pink complex with Y(III), which is also fluorescent with apparent pH 4.5-6.7 (12). At pH higher than 6.7, provided by NH,OH, with an appropriate concentration of 1,4-DHAn and Y(III), a solid violet complex forms. In this paper the I,4-DHAn-Y(II1) complex is spectrophotometrically and spectrofluorometrically studied in water-ethanol solution and also in the solid state. ’ To whom correspondence
should be addressed. 270
0026-265X/86 $1 SO Copyright 6 1986 by Academic Press. Inc. All rights of reproduction in any form reserved.
I ,4-DIHYDROXYANTHRAQUINONE-YlTRIUM(II1)
MATERIALS
271
AND METHODS
Reagents. The chemicals used were of analytical grade. A lo-* M Y(II1) stock solution (deionized water) was prepared by weighing Y(NO,), * 5H,O and was standardized using the complexometric method. A solution of 10e3 M 1,4-DHAn (Merck R.A. recrystallized in ethanol) was prepared by weight and dissolved in ethanol. The other solution used in this study was prepared by dilution of these stock solutions. Apparatus. A Perkin-Elmer Model Lambda-5 spectrophotometer was used with cells of l-cm optical path length. Fluorescent measurements were carried out with a Perkin-Elmer MPF-43 spectrofluorometer with a thermostat cell holder for l-cm quartz cells. A Crison Model 501 pHmeter was used as well. Infrared spectra, in the region 4000-200 cm-i of sample in KBr pellets, were recorded using a Beckman 4250 spectrophotometer. Thermogravimetric studies on the isolated complex were carried out in a dynamic atmosphere of pure air (100 ml mini) on a Mettler TG 50 thermobalance with a heating rate of 10°C mini. The DSC curves were recorded on a Mettler differential scanning calorimeter (Model DSC-20) at a heating rate of 5°C min-’ in the temperature range of 35-550°C. The elemental analyses were performed on a Carlo Erba microanalyzer (Model 1106). Prepuration of the 1,4-DHAn- Y(ZZZ) solid complex. To 1.2 liters of low3 M ethanolic solution of 1,4-DHAn and at a temperature of 75”C, was added, slowly and shaking, 200 ml of 2 x lop3 M aqueous solution of Y(NO,), * 5H20. Afterward, 1 M NH,OH solution was slowly added, until an apparent pH 6.7 was reached. Then a blue-violet precipitate immediately occurred. After 1 hr the complex was filtered, washed with ethanol NH,OH mixtures, and vacuum-dried on H,SO, for several days. RESULTS
AND DISCUSSION
Spectrophotometric Study The ligand and cation concentrations used were 8 x lop5 M and the waterethanol relation was maintained constant at 20-80%, the study of the apparent pH influence on the complex absorption spectrum was accomplished by the addition of different concentrations of NH,OH. The complex shows an optimum formation with maximum absorption at apparent pH 5.7-67.0 (pink form, A,, = 525 and 560 nm) (Fig. 1). When the apparent pH is greater than 6.7 we are able to observe clearly the violet form (A,, = 535 nm) which precipitates as a solid complex in a few minutes. The ligand does not change its absorption spectrum in the studied interval of apparent pH (4.8-8.7). The water-ethanol relation in the medium affects the pink complex formation appreciably, the optimum relation of this being 20-80%. Under these conditions and with an apparent pH 5.8 fixed, it was verified that the complex solutions are stable in an hour’s time. The absorbance of complex solutions increase with the ligand concentration up to the ratio ligand:Y(III) of 6: 1, and then remains constant (measurements were made opposite a ligand solutions as blank). The plot of absorbance versus concentration of cation at 560 nm gave a straight line in the
272
ROMAN
ET AL.
0.7
0.5
0.3
al
150
500
550
600
650
Mnml
FIG. 1. Absorption pH = 8.5.
spectra. (I) Ligand; (2) complex, apparent pH = 5.8; (3) complex,
region of 1 to 7 ppm. This confirmed that the Lambert-Beer law was valid. For the molar absorptivity Ebb, a value of 12,000 liter bmol-km-l was found. The stoichiometry of 1,4-DHAn-Y(II1) complex in solution was studied by the continuous variations (Job) and the molar ratio (Yoe-Jones) methods. In both methods the stoichiometry was 1:l (Fig. 2). The formation constant calculation was realized applying the methods of Holme and Langmyhr (6), Roman ef al. (13, and by using Job’s plot (7). All methods gave similar values for the log K of 4.57.
0.9 I
x ‘\
/I0I .“-i /
I
,
0.5 -
I
\
\
.\\\ \\ \
1 02
0
0
J
i
0
0
0.1 19 a1
03
05
IYl11lO I [Ligandl FIG.
2. Job’s method. [Ligandl
+ [Y(lll)I
I
0.7
I
09
J
+CYIIIIlI
= 2 x 10e3 M. (1) A = 560 nm, (2) h = 525 nm.
1,4-DIHYDROXYANTHRAQUINONE-YTTRIUM(III)
Spectrojluorometric
273
Study
As our experiments have shown, the pink complex is fluorescent and the violet complex is not fluorescent. The excitation and emission spectra of the pink 1,4DHAn-Y(III) complex were registered with a solution 4 x low5 M in ligand and Y(M), in 20-80% water-ethanol medium at an apparent pH of 5.8. The complex shows two excitation maximums at 525 and 560 nm and emission maximum at 580 nm independent of the excitation wavelength. The ligand similarly treated presents more emission at 525 nm that at 560 nm (Fig. 3). In order to evaluate the effect of pH, this was changed in the apparent pH range 4.8-6.7 with NH,OH solution; at lower apparent pH there is no complex formation and at higher apparent pH the violet nonfluorescent complex is formed; the maximum fluorescent intensity was obtained for apparent pH 5.6-6.0. The study of the effect of water content in the medium show that the fluorescence is maximum for 20-30% water. To check the effect of other variables in the fluorescent properties of 1,4DHAn-Y(II1) complex, we fixed the following parameters: [Ligand] = [Y(M)] = 4 x lop5 M, apparent pH = 5.8, A,, = 560 nm, A,, = 580 nm, water-ethanol ratio = 20-80%; under these conditions we can observe that the complex is stable for an hour, the order of addition of reagent in the sample preparations have no influence on the result, and that the fluorescent intensity remains constant with the temperature between 14 and 26°C. The effect of ligand concentration was tested at a constant Y(II1) concentration of 4 x 1O-5 it4 by systematic variation of ligand concentration; the intensity of fluorescent emission of the complex was determined against a blank solution of the ligand. The results show a linear relationship between fluorescent intensity and ligand concentration up to 4 x 10e5 M. At higher ligand concentrations a quenching
Xlnm)
FIG.
(2) and
3. (1) Complex excitation A,, = 560 nm (2’). Ligand
spectrum, emission
A,, = 580 nm. Complex emission spectra, X,, = 525 nm spectra, h,, = 525 nm (3) and A,, = 560 nm (3’).
274
ROtiN
ET AL.
fluorescence by concentration is observed (Fig. 4). At a fixed ligand concent tion (4 x 10e5 M), the study of the influence of Y(II1) concentration on the co plex formation is carried out between 4 x 10e6 and 2.8 x 10s4 M Y(U), and t results show a linear relationship between fluorescent intensity and Y(II1) c( centration up to 4 x 1O-5 M (between 0.35 and 3.5 ppm). The methods of Yoe-Jones and Job for stoichiometry and the methods Roman er al. and Holme and Langmyhr for the formation constant calculati gave similar values by the spectrofluorometric as by spectrophotometric tee nique . Study of I ,4-DNAn-
Y(ZZZ)Solid Complex
The elemental analysis of the isolated complex, prepared as we previously dicated, was: C, 61.16; H, 2.33 (calculated for Y(C,, H,, Oi2); C, 62.54%; 2.62%. These results suggest that the solid complex presents a stoichiometry 3: 1, ligand:Y(III). The thermal behavior of this complex has been studied from their TG and D! diagrams (Fig. 5). It can be seen in these diagrams that water is not present because the saml was previously introduced in a dessicator with CaCl,. On the other hand, TG diagrams indicate that the complex is thermically stat up to 205°C; at this temperature the pyrolysis of the anthraquinone ring star This process takes place in two steps and finishes at 500°C and is responsible f the strong exothermic effect at 433°C in the DSC curve. The residue of the pyrolysis correspond to 13% of the initial sample weigl This value is in positive agreement to the theoretical value required for Y, (13.74%). The nature of the residue was corroborated from its powder X-ray d gram, which coincides with the card 5.574 (ICPDS) (2) for the cubic Y,C showing highest intensity at d = 3.05 w
I
5
FIG. 4. Effect of the amount of 1,4-DHAn. A,, = 560 nm, h,, = 580 nm, end vol. = 25 ml.
275
I .4-DIHYDROXYANTHRAQUINONE-YTTRIUM(II1) TEMPERATURE TEMPERATURE , .
OC
HEAT FLOW EXOTHERMAL 20.w ti
OC WEIGHT
GAIN
+
-
DTG
FIG. 5. TG and DSC diagrams for I,4-DHAn-Y(III).
There are two bands due to v(C=O), one of them (1590 cm-i) is not shifted with regard to the free ligand (1,4-dihydroxyanthraquinone), and the other one (1620 cm-i) corresponds to the C = 0 bonded to Y(Ci4H70& and is shifted to a lower wavenumber (10 cm-‘) with relation to the free ligand, this suggests the carbonyl group is coordinated with the metallic ion Y(II1). REFERENCES 1. Babko, A. K., Akhmedli, M. K., and Granovskaya, P. B., Photometric determination of yttrium subgroup rare earth elements. Uch. Zap. Azerb. Gos. Univ. Ser. Khim. Nauk 2, 48-52 (1970); Zh. Khim. 19GD, 3G80 (1971). 2. Berry, L. G., “Inorganic Index of Powder Diffraction File,” Published by J.C.P.D.S., Philadelphia, 1974. S. Busev, A. I., Tiptsova, V. G., and Ivanov, V. M., “Analytical Chemistry of Rare Element,” pp. 90-93. Mir Publisher, Moscow, 1981. 4. Eremin, Yu. G., and Bondarenko, G. I. Modern analytical methods for the determination and separation of yttrium. Zavod. Lab. 38, 796-801 (1972). 5. Fernandez-Gutierrez, A., and Mufioz de la Petia., Determination of Inorganic Substances by Luminiscence Methods. In “Molecular Luminiscence Spectroscopy” (S. G. Schulman, ed.), Part I, pp. 371-546. Wiley-Interscience, New York, 1985. 6. Holme, A., and Langmyhr, F. J., Modified straight-line method for determining the composition of weak complexes of the form A,B,. Anal. Chim. Acra 36, 383 (1966). 7. Meites, L., and Thomas, H. C., “Advances in Analytical Chemistry.” McGraw-Hill, New York, 1958. 8. Menkov, A. A., and Bocharova, R. I., Organic reagents for the spectrophotometric determination of yttrium. Fiz. Metody Issled. Anal. Biol. Ob’ektov Nekok. Tekh. Mater.. 43-50 (1971); Zh. Khim., 1972 Abstr. No 2G84. 9. Moeller, T., The coordination chemistry of yttrium and the rare earth metal ions. Chem. Rerf. 65, l-50 (1965).
276
ROMAN
ET AL.
10. Poluektov, N. S., Sandu, M. A., and Lauer, R. S., Comparative study of reagents for determining rare earth elements in a binary mixture. Zavod. Lab. 36, 1425-1428 (1970). II. Roman, M., Fernandez-Gutierrez, A., Gonzalez Garcia, D. V., and Marin, C., Determination fotometrica y fluorimetrica de Y(II1) Quim. Anal. 4, 23-38 (1985). 12. Roman, M., Femandez-Gutierrez, A., and Marin, C., Estudio espectrofluorimetrico y reaccionabilidad fluorescente de algunas hidroxiantraquinonas. Ajhidad 34, 481-486 (1977). 13. Roman, M., Mmioz Leyva, J. A., and Jimenez Sanchez, J. C. A new method for determining the composition and stability constant of complexes of the form A,B,. Anal. Chirn. ACM 90, 233-231 (1977).