119mSn Mo¨ssbauer and i.r. study of esters of tin and lead

352

Notes

DISCUSSION Generally for a given metal ion in a particular metal ligand system, the successive formation constants follow the sequence log KI > log K2 > log Ka. This is true for the chelates of the trivalent metal ions formed with BPHA. The differences in the values of the successive formation constants being not much, it is apparent that equal tendencies for the formation of MR 2+, MR~ +~ and MRs exist even at the commencement of the titration. The order of overall stability constants of the metal chelates follows the sequence Ga>Al>

In, a n d S c > Y > L a

which is the order of the 3rd ionisation potentials of the metals. The high values of the overall stability constants of the metal chelates accounts for the successful analytical applicability of BPHA as a gravimetric reagent for some of the above metals [8]. Department of Chemistry Presidency College Calcutta-12 India

M . R . SEN G U P T A H . R . DAS S . C . SHOME

8. A. D. Shendrikar, Talanta 16, 51 (1969).

J. inorg, nucL Chem., 1972, Vol. 34, pp. 352-357.

Pergamon Press.

Printed in Great Britain

119mSnMiJssbauer and i.r. study of esters of tin and lead (Received 14 May 1971) DIFFERENTIATING between open-chain and cyclic forms of compounds is a current problem in organotin chemistry. We report here the results of an investigation by i.r. and 11~mSn M6ssbauer techniques of some organo-tin and lead esters where both structures are possible. Tin(II) oxide has been reacted with o-dihydric phenols [ 1], salicyclic acid [2] and their derivatives [3] to yield heterocycles containing tin(II) atoms which sublime in vacuo, presumably entering the gas phase as monomers. Some dissolve and can be recovered unchanged from strongly donating solvents where ebullioscopic molecular weight determinations show the presence of monomeric structures [4]. Dialkyltin(IV) dichlorides [5, 6] and oxides [7] have been similarly reacted and the products formulated with cyclic structures, although intermolecular tin-oxygen association in the solid appears necessary to explain the physical and spectroscopic properties of both the tin(II) [8] and tin(IV) derivatives.

1. G.T. Cocks and J. J. Zuckerman, Inorg. Chem. 4, 592 (1965). 2. D. E. Fenton, R. R. Gould, P. G. Harrison, T. B. Harvey, III, G. M. Omietanski, K. C-T. Sze and J. J. Zuckerman, Inorg. Chim. Acta 4, 235 (1970). 3. P. G. Harrison, W. D. Honnick andJ. J. Zuckerman, Unpublished results. 4. J.J. Zuckerman, J. chem. Soc. 1322 (1963). 5. H.J. Emel6us andJ. J. Zuckerman, J. organometal. Chem. 1,328 (1964). 6. M. Ohara, R. Okawara and Y. Nakamura, Bull. chem. Soc. Japan 38, 1379 (1965). 7. S. H. Sage and J. J. Zuckerman, Unpublished results. 8. A.J. Bearden, H. S. Marsh andJ. J. Zuckerman, lnorg. Chem. 5, 1260 (1966).

Notes

353

Metallic lead [4] and lead(II) chloride [5] produce materials whose infrared spectra are analogous to the tin(II) derivatives, but which decompose to form lead(II) oxide at very high temperatures in vacuo. O Sodium salicylate reacts with dimethyltin dichloride in aqueous solution to give (CH3)zSn-(O- H4OH-o)2 in what is reported to be salt formation through the carboxylate group [9], but more recent studies of dimethyltin(IV) derivatives of strong acids suggest a non-ionic structure in the solid state [10]. Dimethyltin-[9] and dimethyllead phthalate, dimethyltin oxalate monohydrate[6, 9, 11] and carbonate [ 10(c)], and tin(II) and lead(II) phthalate and oxalate were prepared from potassium hydrogen phthalate, oxalic acid and sodium carbonate, respectively, in aqueous solution. Dimethyltin molybdate and tungstate were similarly prepared from the potassium salts. Dimethyltin phthalate sublimes in vacuo at 360 ° together with trace amounts ofphthalic anhydride formed presumably in an accompanying decomposition reaction. The i.r. spectrum of the solid shows a v(C=O) shifted to 1585 cm -~ from 1695 cm -~ in the free acid and absorptions in the KBr region at 589 and 528 cm -~ attributed to V~m and V~m(SnC2) in a bent dimethyltin structure[12]. Dimethyltin oxalate monohydrate [6, 9] sublimes in vacuo at 330 ° with much decomposition. Two carbonyl stretchiug frequencies are seen in the i.r., one medium band at 1702 cm -~ in the range of the free acid with another stronger band shifted to 1630 cm -1. Only one absorption (at 600 cm -~) is seen in the methyltin stretching region and we assign this to V~m(SnC2) in a linear dimethyltin structure [ 12]. Both o-phenylenedioxy-[5-7] and 2,2'-biphenylenedioxy-dimethyltin[4, 7] are sublimable solids; the latter is monomeric in pyridine[5]. Each shows two absorptions in the methyltin stretching region at 581 and 525 and at 590 and 523 cm -x for vasymand Vsym(SnC2), respectively, in bent dimethyltin structures. Tin(II) phthalate and oxalate both decompose on attempted sublimation at 340 ° in vacuo, the former yielding phthalic anhydride. The carbonyl frequencies are shifted to 1577 and 1630 cm -~ respectively with a broad, medium band near 1700 cm -~ in the oxalate derivative. All the lead derivatives studied decompose before subliming; all showed carbonyl frequencies shifted to lower energies from the free acid values: lead(II) oxalate 1620 and 1590, phthalate 1535 and 1518, dimethyllead oxalate 1630 and 1585, phthalate 1553 and 1525 cm -1. Dimethyltin molybdate and tungstate decompose before subliming. The dimethyltin stretching region was obscured in the tungstate, but two bands were seen in the molybdate at 603 and 531 cm-L which can be assigned to V~ym and Vssm(SnC0, respectively, in a bent dimethyltin structure[12]. In each compound we find a large splitting of the v3 frequency of the anion (from 895 to 940, 908 and 878 cm -~ in the molybdate and from 833 to 950, 878 and 800 cm -~ in the tungstate)[13, 14] which seems explicable only in terms of anion groups of C2~ or lower symmetry involved in bridging between dimethyltin groups or fixed in a bidentate way in a cyclic structure, as has been suggested for dimethyltin chromate [ 10(b)]. The dimethyltin group is non-linear in dimethyltin phthalate whose structure apparently involyes strong coordination to tin from the carbonyl oxygen atoms as demonstrated by the large shift of v(C-O) to lower energies. From the M6ssbauer parameters in Table 1, the values o f p (= Q.S./I.S.) for the tin(IV) derivatives are with one exception found to be > 2-1 which also argues for some intermolecular

9. E. G. Rochow, D. Seyferth and A. C. Smith, Jr.,J. Am. chem. Soc. 75, 3099 (1953). 10. (a) C. C. Addison, W. B. Simpson and A. Walker, J. chem. Soc. 2360 (1964); (b) H. C. Clark and R. G. Goel, lnorg. Chem. 4, 1428 (1965); (c) idem., J. organometal. Chem. 7, 263 (1967). 11. Dehydration of the monohydrate failed to take place in vacuo at room temperature or during a week at 130° under atmospheric pressure: complete dehydration was accompanied by extensive decomposition as shown by discoloration and the appearance of several new lines in the M~issbauer spectrum. 12. R. Okawara and M. Wada, Advan. organometal. Chem. 5, 137 (1967). 13. K. Nakamoto, Infrared Sffectra o f Inorganic and Coordination Compounds. Wiley, New York (1963). 14. In both cases one of these bands may be associated with the vl frequency of the anion [H. Stammreich, D. Bassi and O. Sala, Spectrochim. Acta 12, 403 (1958)].

JINC. Vol. 34. No. I - L

354

Notes Table 1.119mSnM~ssbaner data in ram/s*

Tin(II) Oxalate

Tin(II) Phthalate Dimethyltin(IV) Oxalate monohydrate Dimethyltin(IV) Phthalate Dimethyltin(IV) Molybdate Dimethyltin(IV) Tungstate Dimethyltin(IV) Carbonate Dimethyltin(IV) Carbonate/AgC1 o-Phenylenedioxydimethyltin(IV) o-Phenylenedioxydiethyltin(IV) o-Phenylenedioxydi-n-butyltin(IV) o-Phenylenedioxydioctyltin(IV) 2,2'- Biphenylenedioxydimethyltin(IV)

I.S.

Q.S.

F1

I~2

p

3.47---0-10§§ 3.90---0.10t 3.59 ± 0.02~ 3.28 ---0.10 1.47 ... 0.06 (-0.55 ± 0.05) II 1.52...0.10§§ 1"48 ± 0.10 (-0.68---0.05) II 1.38 ± 0.10 ( - 0 . 7 1 ± 0 . 0 5 ) I~ 1.47 ... 0.10 1.31...0.10 1.14 ---0.10~ 1.32--0-05'*tt 1.50±0-05**tt 1.29 ± 0.10¶ 1.52 ± 0 . 0 5 * * t t 1 - 3 6 - 0.05**tt 1.15 +--0. I0¶

1.59-0.12§§ 1.40_0.10t 1.52 ± 0-02~ 1.55 ± 0.12 4-41 ± 0.12 4.65 ,±0.05 II 3.63...0.12§§ 4.20 ± 0.12 4-10,±0.05 II 3.46 ± 0.12 3.53 ... 0.0Y I 2.71 ± 0.12 3.02...0.12 3.24 ---0.12¶ 3.35** 3.60** 3.40 ± 0.12¶ 3.62* 3.41" 3.23 - 0.12¶

1.35

1.30

1.22§ 1.27

1.22§ 1.29

0.46 0.36 0-42 0.47 3.00

1-15 1.41

1.28 1.43

2.39 2.84

1.26

1.42

2.51

1.33§ 1.13 1-56

1.33§ 1.19 1.48

1-56

1.48

1.84 2.31 2.84 2.53 2.40 2.64 2.38 2.51 2.81

*All data recorded at liquid nitrogen temperature vs. BallamSnOa absorber at R.T. Compounds marked by §§ were examined at room temperature. tM. Cordey-Hayes, J. inorg, nucl. Chem. 26, 915 (1964). ~J. K. Lees and P. A. Flinn, J. chem. Phys. 48, 882 (1968). §Equal line width constraint in data reduction. IJM. Vucelic, Croat. Chem. Acta 40, 255 (1968); the I.S. values are with respect to grey tin as the absorber reference. Error limits are as assigned by the author. ¶Run at liquid nitrogen temperature vs. 119mSnO2at R.T. * *A. G. Davies, H. J. Milledge, D. C. Puxley and P. J. Smith, J. chem. Soc. A, 2862 (1970). i'tThe quoted I.S. is with respect to SnO~ at 77°K. coordination to tin in the solids[15]. If tin were 6-coordinated in the phthalate, the presence of Vsym(SnC2) in the i.r. would specify either a cis- or a greatly distorted trans-geometry with resultant quadrupole splittings of ca. 2 and ca. 4 mm/s, respectively [16]. The observed splitting of 3.63---0.12 mm/s seems clearly to rule out the cis-structure. Trans-dimethyl geometries are more usual for the 6-coordinate octahedral complexes [ 12, 17], as are equatorial geometries for the 5-coordinate trigonal bipyramidal complexes[12]. Such equatorial geometry in the (CHshSnCla- anion[18] produces a quadrupole splitting of 3.30 to 3-75 mm/s [ 19, 20]. On this basis we may propose for the solid phthalate either a 5-coordinate structure with equatorial methyl groups, or a highly distorted 6-coordinated octahedral structure with trans-methyl groups. The latter appears more probable, as it is difficult to conceive a 5-coordinate structure of the proper stoichiometry in which all of the ~ groups are 15. R. H. Herber, H. A. St6ckler and W. T. Reichle, J. chem. Phys. 42, 2447 (1965); W. T. Reichle, lnorg. Chem. 5, 87 (1966). 16. B. W. Fitzsimmons, N. J. Seeley and A. W. Smith, Chem. Comm. 390 (1968); J. chem. Soc. A, 143 (1969). 17. But see the recent structural determination of dimethyltinbis(8-hydroxyquinolinolate) [E. O. Schlemper, lnorg. Chem. 6, 2012 (1967)]. 18. F . W . B . Einstein and B. R. Penfold, Chem. Comm. 78 (1966); J. chem. Soc. A, 3019 (1968). 19. N . W . G . Debye, E. Rosenberg and J. J. Zuckerman, J. Am. chem. Soc. 90, 3234 (1968). 20. R. V. Parish and R. H. Platt, lnorg. Chim. Acta 4, 65 (1970).

Notes

355

coordinated. Two analogous structural possibilities are present in each of o-phenylenedioxy and 2,2'biphenylenedioxydimethyltin, but their quadrupole splittings are ,~ 4 minis, indicating that 5-coordination about tin is the more probable. Non-linear dimethyltin groups are found for the carbonate as well where distorted COs groups of C~v or lower symmetry are dictated by the i.r. evidence [ 10(c)]. The MiSssbaner data for the compound formed in an AgCI matrix are consistent with equatorial methyl and bridging carbonato groups in a polymeric trigonal bipyramidal structure. Such a structure could include chloride interactions from the AgCI to give the analogue of the bridged carboxylates [ 12]. Samples prepared from sodium or potassium carbonate gave unchanged infrared, but MiSssbauer spectral data consistent with a 4-coordinate structure (p = 1"84) utilizing a bidentate carbonate group. In dimethyltin oxalate monohydrate the absence of Vsym(SnCz) and the presence of a medium, broad band in the free carbonyl region (1702 cm -1) with a MiSssbauer quadrupole splitting of 4.41 +-0-12 mm/sec, specify a trans-octahedral geometry involving bridging carboxylate groups. A sixth position is occupied by a water molecule, and one carboxylate group is bound as an organic ester:

-1 Sn

I

/

I \o"C%/

CHs

_]~

Depending on the sample preparation an additional weak feature was occasionally seen at ca. 510 cm -1, indicating some distortion of the linear dimethyltin group, although not sufficient to change the Mtissbauer data. Many derivatives of dicarboxylic acids are polymeric, but cyclic tetrameric [20] and dimeric structures are also known[21]. In the case of di-n-butyltin maleate a monomeric monohydrate has been isolated [22]. The M~issbauer values for the dimethyltin derivatives recorded in Table I are in the range observed for diorganotin(IV) dicarboxylates (isomer shift 1.24-1.55; quadrupole splitting 3"10-3.70 mm/s)[23]. The valence state of the tin(II) compounds is confirmed by their high isomer shifts[23, 24] and, together with their quadrupole splittings, are in the general range reported for tin(lI) earboxylates [25]. The physical properties of these non-sublimable solids indicate a strongly polymeric structure with carboxylate bridging. Here again, however, the oxalate shows the presence of a free carbonyl group in the i.r. and we propose a structure in accord with the usual 3-coordinated, pyramidal configuration for tin(II) [26].

/

~c----c~. /

LO

o ~:1-~

EXPERIMENTAL Our cam-drive, constant-acceleration spectrometer, method of data collection[8], and data refinement techniques [27] have been described. Spectra were obtained with either a Ba l l g m SnOz or 119~,/SnO2 source (both supplied by New England Nuclear Corp.), and all isomer shifts are reported with respect 20. T. M. Andrews, F. A. Bower, B. A. Laliberte and J. C. Montermoso, J. Am. chem. Soc. 80, 4102 (1958). 21. N. A. Solvokhotova, N. A. Faizi, N. N. Zemlyanskii, E. M. Panov and K. A. Kocheshkov, Zhr. obsch. Khim. 33, 2610 (1963). 22. A. S. Mufti and R. C. Poller, J. chem. Soc. C, 1362 (1967). 23. J.J. Zuckerman, Advan. organometal. Chem. 9, 21 (1970). 24. J.J. Zuckerman, Mi~ssbauer Effect Methodology 3, 15 (1967). 25. J. D. Donaldson and A. Jelen, J. chem. Soc. A, 1448 (1968). 26. J. D. Donaldson, Prog. lnorg. Chem. 8,287 (1967). 27. N. W. G. Debye, D. E. Fenton, S. E. Ulrich andJ. J. Zuckerman, J. organometal. Chem. 28, 339 (1971).

356

Notes

to a room temperature SnO2 absorber. Microarlalyses were carried out by Galbraith Laboratories, Inc. and i.r. spectra were recorded on a Beckman I R- 10 spectrometer. Mtissbaner data are listed in Table 1, i.r. data in Table 2. Table 2. I.R. data in cm -1 v(C==O) Phthalic acid Tin(II) phthalate Lead(II) phthalate Dimethyltin phthalate Dimethyllead phthalate

1695 1577 1535, 1518 1585 1553, 1525

Tin(II) oxalate Lead(II) oxalate Dimethyltin oxalate monohydrate Dimethyllead oxalate Dimethyltin molybdate Dimethyltin carbonate/AgC1 o-Phenylenedioxydimethyltin 2,2'-Biphenylenedioxydimethyltin

1700,1630 1620,1590 1702,1630 1630,1585

v,~vm(SnC2) V~m(SnC~)

589

528

600 603 576* 581 590

531 523* 525 523

*H. C. Clark and R. G. Goel, J. organometal. Chem. 7, 263 (1967).

Dimethyltin carbonate Saturated aqueous solutions of dimethyltin dichloride and sodium or potassium carbonate gave white precipitates which were identified by their i.r. spectrum [ 10(c)], and did not melt at 360 °. Another sample was made by the method of Ref. 10(c) which produces the compound in a matrix of silver chloride.

Tin( l l ) phthalate Aqueous solutions of tin(II) chloride and potassium hydrogen phthalate gave a white precipitate, m.p. 353 °. (Anal. Calcd. for CsH404Sn: C, 34"0; H, 1"4; Sn, 42"0%. Found: C, 31"58; H, 1"43; Sn, 42.36%.)

Dimethyllead phthalate Prepared similarly from dimethyllead dichloride to give a white precipitate, m.p. 342 ° (with decomp.). (Anal. Calcd. for Cl0H1004Pb: C, 29.9; H, 2'5%. Found: C, 29" 14; H, 1.39%.)

Lead( l l ) phthalate Prepared similarly from lead(II) chloride to give a white precipitate, m.p. 334 ° (with decomp.). (Anal. Calcd. for CsH404Pb: C, 25.9; H, 1.1%. Found: C, 28.44; H, 1.3%.) Lead(II) oxalate was prepared similarly from oxalic acid, decomp, at 300 °. An extension of this method to dimethyllead oxalate and molybdate was made, but satisfactory analytical data for the white, lead-bearing precipitates could not be obtained, even considering the possible formation of the basic salts.

Acknowledgments-We thank Mr. B. Y. K. Ho for assistance with the M6ssbauer measurements, Dr. W. R. McCormack of the Organic Chemicals Department, E. I. DuPont de Nemours and Company, Inc. Wilmington, Delaware for a sample of dimethyllead dichloride and Professor Rokuro Oka-

Notes

357

wara of the University of Osaka, Osaka, Japan for helpful discussions. Our work is supported by the National Science Foundation under Grant GP- 16544.

Department of Chemistry State University of New York at Albany Albany, N.Y. 12203 U.S.A.

N. W. G. DEBYE* D. E. F E N T O N * J. J. Z U C K E R M A N

*Present address: Institute for Materials Research, National Bureau of Standards, Washington, D.C. 20234, U.S.A. *Present address: Agricultural Research Council, Unit of Structural Chemistry, Inveresk House, 346 Strand, London WC2R O H G , England.

J. inorg,nucl.Chem., 1972,Vol. 34, pp. 357-359. PergamonPress. Printedin Great Britain

Lanthanon(IIl) complexes with ethanediol, propane-12-diol and glycerol in aqueous medium (Received 23 April 1971) THOUGH THE lanthanon(III) complexes with a-hydroxycarboxylic acids have been extensively studied, those with polyhydroxy compounds do not appear to have been investigated. In the present communication, the results of our investigations on the lanthanon(III) complexes with ethanediol, propane- 1,2-diol and glycerol are reported in aqueous medium containing 0.100 M sodium perchlorate at 22° using pH-metric titration method [ 1]. EXPERIMENTAL Lanthanon(III) perchlorates and sodium hydroxide was prepared as described earlier[2]. B D H samples of ethanediol, propane-l,2-diol and glycerol were used after distillation under reduced pressure. The titration procedure adopted was the one similar to that described by Irving and Rossotti[1], except that the pH of the lanthanon solutions was adjusted to 3.00 resulting in the concentration of the mineral acid as 1 x 10-3 M. All the titrations were carried out in aqueous medium containing 0.100 M sodium perchlorate at 22 _+ 1°C.

Calculations From the titration curves, the average number of the organic ligand molecule attached per lanthanon(lll) ion (= ~) was calculated using the equation proposed by Irving and Rossotti [1]. Since the dissociation constant (K,) of these reagent molecules (the glycols) could not be accurately determined in aqueous solutions (PKa > 13), the formation functions for the lanthanon(III) complexes of these reagents could not be calculated in the conventional sense[3]. In this case however, the equilibrium constant for the reaction 1. H. Irving and H. S. Rossotti, J. chem. Soc. 2904 (1954). 2. Gurcharan Singh Manku, J. inorg, nucl. Chem. 33, 285 (1971). 3. F. J. C. Rossotti and H. Rossotti, Determination of Stability Constants. McGraw Hill, New York (1961).