hydrogen phosphate and hydrogen uranyl phosphate ...

Ion exchange reactions of n-butylamine intercalates of tin(1V) hydrogen phosphate and hydrogen uranyl phosphate with cobalt(II1) complexes RAFAELAPOZAS-TORMO,LAUREANO MORENO-REAL,M A R ~MART~NEZ-LARA, A AND ENRIQUE RODR~GUEZ-CASTELL~N' Departarnento de Quimica Inorganica, Facultad de Ciencias, Universidad de Mdlaga, 29080 Mdlaga, Spain Received May 1, 1985

Can. J. Chem. Downloaded from www.nrcresearchpress.com by 213.143.60.107 on 12/29/13 For personal use only.

RAFAELA POZAS-TORMO, LAUREANO MORENO-REAL, M A R ~MART~NEZ-LARA, A and ENRIQUERODR~GUEZ-CASTELL~N. Can. J. Chem. 64., 35 (1986). ~ , The ion exchange reactions of n-butylamine intercalates of tin(1V) hydrogen phosphate and hydrogen uranyl phosphate towards carbonatotetraamrninecobalt(III), chloropentaamminecobalt(III), and hexaamminecobalt(III) have been investigated. Independent of the complex cation charges, the amounts of Co(II1) complex exchanged by the n-butylamine intercalate of tin(1V) hydrogen phosphate are practically the same. With the n-butylamine intercalate of hydrogen uranyl phosphate, the ionic exchange was completed and the composition was fixed by the exchanged Co(II1) complex. The layer charge densities of these phosphates justify the different ionic exchange behaviour observed towards the large complex cations. All the products were characterized by chemical analysis, X-ray diffractometry, infrared spectroscopy, diffuse reflectance spectroscopy, and thermal analysis. RAFAELA POZAS-TORMO, LAUREANO MORENO-REAL, M A R ~MARTINEZ-LARA A et ENRIQUERODR~GUEZ-CASTELL~N. Can. J. Chern. 64, 35 (1986). On a CtudiC les rtactions d'tchange d'ions des composCs d'intercalation entre la butylamine et I'hydrogenophosphate d'Ctain(1V) et l'hydrogtnophosphate d'uranyle avec le carbonatotttraamminecobalt(III), le chloropentaamminecobalt(III) et 1'hexaamminecobalt(III). La charge des complexes cationiques n'influence pas le taux d'ions complexes de Co(II1)CchangCs par les composCs d'intercalation entre la butylamine et 1'hydrogCnophosphate d'ktain. Dans le cas du composC d'interaction entre la butylamine et I'hydrogCnophosphate d'uranyle, l'tchange ionique est totale et le complexe d'ion Co(II1) CchangC en dktermine la composition. Les densitts de charge de la couche de ces phosphates justifient le comportement des diffkrents Cchanges ioniques observts avec les grands complexes cationiques. On a caractCrisC tousles produits obtenus par l'analyse chimique, la diffraction de rayons X, la spectroscopie infrarouge, la spectroscopie de reflexion diffuse et par l'analyse thermique. [Traduit par le journal]

Introduction Tin(1V) hydrogen phosphate monohydrate, Sn(HP04)2.H20 (a-SnP), and hydrogen uranyl phosphate tetrahydrate, HU02PO4.4 H 2 0 (HUP), are layered inorganic ion exchangers ( l , 2 ) . a-SnP crystall~zesin the monoclinic system; the interlayer distance is 7 . 8 A . O n the other hand, H U P crystallizes in the tetragonal system, with an interlayer distance of 8.8 A. The ion exchange behaviour with alkali metals, alkaline earths, and first row transition metals of these phosphates was investigated (3-8). However, very little is known about ion exchange with large complexes on these exchangers. a - S n P is isostructural to a-zirconium hydrogen phosphate (a-ZrP) (1). Complex ions + exchanged using like [co(NH,),]~+ and [ c u ( N H ~ ) ~ ] ~were the monohydrogen forrn, o r the wider-spaced n-butylamine a-ZrP intercalate (9, 10). Cr(II1) Werner complexes have also been exchanged into H U P (1 1 , 12). The n-butylamine intercalated forrns of a - S n P (BASnP) and H U P (BAUP) were chosfn because of their large interlayer distances (19.5 and 14.4 A , respectively), with wide passageways leading to the exchange site that would permit the interlayer penetration of large complexes. The characterization of the exchanged behaviour of BAUP will be reported.

I

I

[ C O ( N H ~ ) ~ C I ]and C ~[~C, O ( N H ~ ) ~were ] C ~synthesized ~ as reported in the literature (16). and (C4H9NH3)Weighed amounts of Sn(C4HIIN)2(HP04)2.H20 U02P04.3H20 were suspended for one day, at 25OC, in aqueous solutions of [Co(NH3)4C03]N03,[ C O ( N H ~ ) ~ C I ]and C ~[Co(NH3),]~, C13, which represented 300% of the exchange capacity. This operation was repeated once. The mixtures were filtered, and the solids were analyzed for their metal, water, and nitrogen contents.

Instr~imentatiorz Metal content was determined using a Varian Techtron 475 ABD atomic spectrophotometer. The nitrogen content was determined by a micro-Kjeldahl method. X-ray films were obtained in Huber DebyeSchemer cameras with diameters of 11.46 cm using a Siemens X-ray generator. A Siemens D-500 diffractometer was used for the X-ray diagrams. The radiation was nickel-filtered CuKa in each case. TG and DTA analyses were carried out using a Rigaku Thermoflex thermoanalyzer, at a heating rate of 10°C min-'. Diffuse reflectance spectra were recorded on a Kontron-Uvikon 810 spectrophotometer with an integrating sphere attachment, which used BaS04 as the reference. Infrared studies were performed on a Beckman 4260 spectrophotometer by the KBr disc method. Anal. calcd. for S ~ [ C O ( N H ~ ) ~49H1.51(P04)2' CO~]~ 1.5H20: Co 6.74, N 6.40; % loss on ignition (TGA to 900°C) (LOI) 22.27; found: Co 6.72, N 6.56, LO1 22.29. Anal. calcd. for S ~ [ C O ( N H ~ ) ~ C I ] ~ . ~ H(P04)*.1 .5H20: Co 6.9 1, N 8.20, LO1 18.43; found: Co 6.98, N 8.00, Experimental LO1 18.36. Anal. calcd. for S ~ [ C O ( N H ~ ) ~ ] ~ . ~ H ~CO ,~(PO~) Preparation 6.69, N 9.54, LO1 24.75; found: Co 6.66, N 9.83, LO1 24.68. Anal. All the chemicals were of reagent grade and were used without Co. H10.34, ~ O : N 9.82, LO1 calcd. for [ C O ( N H ~ ) ~ C O ~ ] U O ~ P O ~ further purification. a-SnP and BASnP were prepared as described 22.83; found: CO 10.76, N 9.40, LO1 23.14. Anal. calcd. for elsewhere (13, 14). HUP was prepared according to the method [ C O ( N H ~ ) ~ C ~ ] ~ . ~ U O ~CO P O5.89, ~ . ~N. ~7.00, H ~ OLO1 : 17.52; proposed by Schreyer and Baes (15). The BAUP was obtained by the Co 5.5, N 6.90, LO1 17.51. Anal. calcd. for [ C O ( N H ~ ) ~ ] ~ . ~ ~ ~, same method used for BASnP. 'The complexes [ C O ( N H ~ ) ~ C O ~ ] N Ofound: U02P04.2.21H20:Co 4.31, N 6.12, LO1 16.75; found: Co 4.40, N 'Author to whom correspondence may be addressed. 6.28, LO1 16.74.

36

CAN. J. CHEM. VOL. 64, 1986

TABLE1. Composition and interlayer distances of the exchanged phases at 25OC


Composition

Interlayer distance (A)

Results and discussion Composition and X-ray data Table 1 shows the composition and the interlayer distance of the exchanged phases at 25OC. The amount of cobalt(II1) complex exchanged by BASnP is independent of the charge of the complex. Although the interlayer distan~esof these compounds are different, a reflection line at 9.1 A was observed in the powder patterns of all the complex exchanged compounds. Because of the crystal distortion suffered in the intercalation process, the X-ray diffraction data of the BASnP derivatives show few reflection lines, and thus the calculation of unit cell constants based on the powder patterns is not possible.' The observed composition results from the "covering effect" of the guest molecule; that is to say, the complex ion bonded to phosphate groups impedes bonding at an adjacent site, as this site is now covered. A similar composition was seen when BAZrP was ion exchanged with tetraamminecopper(I1) (9). With BAUP there was a complete ionic exchange with the complex cations. In this case, the composition is a function of the complex cation charge. This different behaviour between HUP and a-SnP is due to the different layer charge densities. HUP has a smaller layer density than a-SnP and consequently a bigger free area around the active site (48.8 A' for HUP and 21.5 A' for a-SnP (14)). Thus, total saturation with large complex cations can be attained. The hydration stoichiometry of these compounds shows a wide range. Table 3 shows the X-ray crystallographic data for the HUP exchanged phases. All samples could be indexed to tetragonal unit cells. The reflection lines corresponding to the original hkO planes were maintained.3 The absence of hkO lines when h k f 2n demonstrates the retention of the n glide plane of uranyl phosphate. The layer structure has been preserved, while the c axis has varied.

+

9

(cm-3

FREQUENCY FIG. 1. Infrared spectra of (A), S~[CO(NH~)~CO~]~.~~H 1.5Hz0;(B), S~[CO(NH~)~C~IO.~H(P~~)Z. 1.5Hz0;(C),Sn[Co(NHd6]0.5H0.5(P04)2' 3Hz0.

The water stretching in the S ~ [ C O ( N H ~ ) ~ C ~ ] ~ . 1.5H20 (curve B) and S~[CO(NH~)~]O.~HO.~(PO 3H20 (curve C) are not so sharply defined and they are overlapped by the NH3 stretching bands. Generally, the NH3 stretching bands occur at higher frequencies (3300-3200 cm-') because these Infrared spectra frequencies are sensitive to changes in the anion. (The anion of The ir spectra of the exchanged compounds of BASnP are the salts ~.~I( P O(C1-) ~ ) ~is substituted by the layer O3POP.) The shown in Fig. 1. The S ~ [ C O ( N H ~ ) ~ C O ~ ~ ~ . ~ ~ H complex broadening of these bands is the result of hydrogen bonding as 1.51H20 spectrum (curve A) shows bands, due to zeolitic well as the overlapping of the individual N-H stretching bands water, occurring at 3570, 3490, and 1640cm-'; they can be of the complex (18). The NH3 scissoring bands at 1330cm-' superimposed upon those reported previously for a-SnP (17). (curve B), and 1335 cm-' (curve C), are sharp and practically superimposable on those of the original complexes (18). In all 2A table of X-ray powder diffractiondata of S ~ [ C O ( N H ~ ) ~ C O ~cases, ] ~ , ~ ~the - NH3 rocking vibrations shift to higher frequencies H1.51(P04)2. 1.51H20, S~[CO(NH~)~C~]~.~H(PO~)~. 1.51H20, and and overlap the absorption bands of the phosphate group, as this S~[CO(NH~)~]~.~H~.~(PO~)~.~H~O (Table 2, supplementary material) rocking mode is very sensitive to the outer ions and the hydrogen may be purchased from the Depository of Unpublished Data, National bonding (19). The absence of characteristic bands in the region Research Council of Canada, Ottawa, Ont., Canada KIA OS2. of 1500-1400cm-' and the higher frequency shift of the 3Tables of X-ray powder diffraction data of [CO(NH~)~CO~]UO~PO4.H20, [ C O ( N H ~ ) ~U02P04 C ~ ] ~ . ~. 2.5H20, and [ C O ( N H ~ ) ~ ] ~rocking . ~ ~ - mode indicate that the cobalt complex ion is now present as an amine complex and that the ammonia is hydrogenUO2PO4.2.21H20(Tables 4, 5, and 6, supplementary material) may bonded with the layer phosphate (20). The cobalt-nitrogen be purchased from the Depository of Unpublished Data, National Research Council of Canada, Ottawa, Ont., Canada KIA 0S2. stretching bands are very weak and occur near 500cm-'.

37

POZAS-TORMO ET AL.: 2

TABLE3. X-ray crystallographic data of cobalt(II1) complex uranyl phosphates (Cu K,,,,; Compound*

Formula weight

a (A)

c (A)

Z

A

=

v (A3)

1.5418 A, 20°C) dc

do


*All compounds belong to the tetragonal system.

FIG.3. Diffuse reflectance spectra of (A), S ~ [ C O ( N H ~ ) ~ C O ~ ] ~ . ~ ~ H I . s I ( P O ~ 1.5H20; )~. (B), S~[CO(NH~)SC~IO.SH(PO~)~. 1.5H20; (C), S~[CO(NH~)~~O.SHO.~(P~~)~. 3H20. all the spectra. Water bands occur at 3500 and 1630 cm-'. The ammonia stretching vibration bands of these exchanged phases appear at 3300-3200 cm-I. These values are near those previously observed in the a-SnP derivatives. This is to be expected, because the anions in the layered phosphate are similar. The NH3 scissoring bands at 1270- 1370 cm- are very sharp and similar to those of the cobalt(II1) a-SnP complex. The metal-nitrogen stretching bands are better defined than those of a-SnP derivatives, and occur near 500 cm-I. Sometimes these bands are overlapped by the phosphate group bending vibration band. FIG.2. Infrared spectra of (A), [ C O ( N H ~ ) ~ C O ~ ] U OH20; ~ P O ~ . In a comparative study, the spectra of a-SnP and HUP (B), [ C O ( N H ~ ) S C ~ I O . S U ~ ~ (C), P O[Co(NH3)610,33U02P04. ~.~.~H~~; derivatives are seen to be composites of those of the phosphate 2.21H20. layer and the corresponding cobalt(II1) ammonia complex ion. In both series the N H stretching, ~ bending, and rocking modes Phosphate vibration bands centered at 1000 cm-' dominate all shift to higher frequencies due to hydrogen bonding phosphate. the spectra of Fig. 1. The NH3 bending bands at 1620- 1640 cm- overlap the water Figure 2 shows the ir spectra of the exchanged phases of BAUP: bending mode. [ C O ( N H ~ ) ~ CUO2P04. O~] H 2 0 (curve A), [ C O ( N H ~ ) ~ C ~ ] ~ ,In ~ -all cases, the n-butylammonium ion absorption bands of U 0 2 P 0 4 .2.5H20 (curve B), and [ C O ( N H ~ ) U02P04. ~]~.~~ the starting material disappeared. 2.21H20 (curve C). These spectra are well defined; there is a Diffuse rejectance ultraviolet-visible spectra strong absorption band centered at 1000 cm-' assigned to phosThe diffuse reflectance spectra of the a-SnP derivatives (Fig. phate stretching (21), and a sharp band at 925 cm-' assigned to 3) and the HUP derivatives (Fig. 4) are very different. In the the u O i f asymmetric stretching vibration; the two dominate

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CAN. J . CHEM.

FIG. 5. DTA-TG curves of S~[CO(NH~)~CO~]O.~QH~ (P04)2. 1.5H20.

region impedes the detection of the corresponding bands assigned to the t 'A l g transition. From these data we conclude that the Co(II1) complex ions are present in the exchangers.

Thermal data The thermal behaviour of the a-SnP derivatives and HUP derivatives was investigated. As representative examples, we show the decomposition processes of S ~ [ C O ( N H ~ ) ~ C O ~ H1.51(P04)2.1.5H20 and [ C O ( N H ~ ) ~ ] ~ 2.21H20. . ~ ~ U ~ ~ In the DTA-TG curves of the former compound (Fig. 5), three different stages can be seen. The first (DTA peak at 84°C) corresponds to the removal of the water of crystallization. The FIG.4. Diffuse reflectance spectra of (A), [CO(NH~)~CO~IUO~POJ. second corresponds to the evolution of ammonia and carbon dioxide. Finally, the condensation of orthophosphate to pyrophosphate takes place between 400 and 500°C. In the X-ray powder diffraction pattems of the sample heated at 900°C, SnP20, could be identified4 (25). This confirms the presence of former, the layered phosphate is inactive in the 300-900 nm the proton in the exchanged compound. However, the expected region. However, the HUP diffuse reflectance spectrum shows Co304 could not be detected. This spinel is the final product many sharp peaks in the 340-500 nm region; these are derived when [ C O ( N H ~ ) ~ C O ~ ] ~ S O is ~heated . ~ H ~atO800°C (26). from the spectrum of the uranyl moiety (22). The thermogravimetric curve of [ C O ( N H ~ ) ~ ] O . ~ ~ The spectra of the a-SnP derivatives correspond to the fol2.21H20 (Fig. 7) indicates that the decomposition of this lowing ions exchanged: carbonatotetraamminecobalt(III), with compound occurs in three stages. The first corresponds to the maxima at 5 15 and 350nm (curve A); chloropentaammineremoval of water. In the second, the ammonia and nitrogen cobalt(III), with maxima at 520 and 350nm (curve B); and liberation are almost overlapped; the cobalt(II1) ion is reduced, hexaamminecobalt(III), with maxima at 470 and 340 nm (curve as in the case of the hexaamminecobalt(lII) halides (27). The third C). These spectra are practically superimposable on those of the corresponds to the condensation of orthophosphate to pyrophossalt complex employed (23, 24). phate. The DTA curve supports this mode of decomposition. The spectra of the HUP derivatives (Fig. 4) are composed The experimental per cent weight loss on ignition agrees with of those of HUP and the cobalt(II1) complex ions. All the the calculated value if the Co(II1) reduction and the condensasamples exhibit similar spectra in the 370-500 nm region. The tion to pyrophosphate are considered. A significant increment absorption bands that correspond to the Co(II1) complex ions of the magnetic susceptibility was observed in the compound overlap; it is only possible to distinguish them at 510nm for [ C O ( N H ~ ) ~ C O ~ ]and - U P[CO(NH~)~CI]-UP, and at 470 nm for 4Figure 6, X-ray powder diffraction patterns of S ~ [ C O ( N H ~ ) ~ C O ~ [CO(NH~)~]-UP. These values observed in the visible region Hl.51(P04)2'1.5H20heatedat 900°C, (Fig. 6, supplementary material) coincide closely with those reported for the complex ions. Howmay be purchased from the Depository of Unpublished Data, National ever, the high absorption of the HUP layer in the ultraviolet Research Council of Canada, Ottawa, Ont., Canada KIA 0S2.


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5. N. G. CHERNORUKOV and G. S. SIBRINA. Zh. Prikl. Khim. 53, 939 (1980). A. RODR~GUEZ-GARC~A, and S. 6. E. RODR~GUEZ-CASTELL~N, BRUQUE. Mater. Res. Bull. 20, 115 (1985); Anal. Quim. In press. 7. F. WEIGELand G. J. HOFFMANN. J. Less Common Met. 44, 99 (1976). 8. M. M. OLKEN,R. N. BIAGIONI,and B. ELLIS.Inorg. Chem. 22, 4128 (1983). 9. A. CLEARFIELD and R. M. TINDWA. Inorg. Nucl. Chem. Lett. 15, 251 (1979). and S. KISAKI.Chem. Lett. Jpn. 241 (1980). 10. Y. HASEGAWA 11. M. M. OLKENand A. B. ELLIS.J. Am. Chem. Soc. 106, 7468 (1984). 12. M. M. OLKEN,C. M. VERSSCHOOR, and A. B. ELLIS.J. Lumin. 31/32, 552 (1984). A. RODR~GUEZ-GARC~A, and S. 13. E. RODR~GUEZ-CASTELL~N, BRUQUE. Inorg. Chem. 24, 1187 (1985). 14. E. RODR~GUEZ-CASTELL~N, S. BRUQUE,and A. RODR~GUEZG A R C ~JA. .Chem. Soc. Dalton Trans. 213 (1985). 15. J. M. SCHREYER and C. F. BAES.J. Am. Chem. Soc. 76, 354 (1954). Inorg. Synth. 6, 173 (1960); T. MOELLER and 16. G. SCHLESSINGER. I I I I I I G. L. KING.Inorg. Synth. 5, 185 (1957); J. BJERRUM and J. P. 100 200 300 400 500 600 MCREYNOLDS. Inorg. Synth. 2, 216 (1946). 17. N. G. CHERNORUKOV. Zh. Neorg. Khim. 26, 535 (1981). TEMPERATURE (OC) 18. K. NAKAMOTO. The infrared spectra of inorganic and coordination ~]~ 2.21H20. FIG. 7. DTA-TG curves of [ C O ( N H ~ )33U02P04' compounds. Wiley-Interscience. New York. 1963. 19. J. FUJITA,K. NAKAMOTO, and M. KOBAYASHI. J. Am. Chem. heated at 600°C. This also supports the Co(1II) reduction to SOC.78, 3295 (1965). Co(I1). 20. Y. HASEGAWA, S. KIZAKI,and H. AMEKURA. Bull. Chem. Soc. Acknowledgement Jpn. 56, 734 (1983). 21. V. PEKAREK and V. VESELY.J. Inorg. Nucl. Chem. 27, 1151 We thank the "Comisi6n A~~~~~~de Investigacibn cientifica (1965). y Ttcnica" for financial support of the work carried out at the 22. H. D. BURROWS and T. KEMP.J. Chem. Soc. Rev. 3,139 (1974). University of MAlaga. 23. D. SUTTON.Electronic spectra of transition metal complexes. McGraw-Hill, London. 1972. 1. N. G. CHERNORUKOV, I. R. MOCHALOVA, E. P. MOSCUICHEV, W. WENDLANDT and H. G. HECHT.Reflectance Spectroscopy. andG. B. SIBRINA.Zh. Prikl. Khim. 50, 1618 (1977). Wiley-Interscience, New York. 1962. 2. A. T. HOWE.In Inorganic ion exchange materials. Edited by A. JCPDS Powder Diffraction File 3-278. Clearfield. CRC Press, Boca Raton, FL. 1982. Chapt. 4. J. M. A M I G ~J., G A R C ~GONZALEZ, A and C. MIRAVITLLES. 3. U. COSTANTINO and A. GASPERONI. J. Chromatogr. 51, 289 J. them. Anal. 3, 169 (1971). (1 970). T. FLORA.Acta Chim. Acad. Scien. Hung. 52, 133 (1967). 4. M. J. FULLER.J. Inorg. Nucl. Chem. 33, 559 (1971).