Manhas, B. S.

Sandhu, G. K.

Sandhu, S. S.

English

NOPR

lodi ••• .Journal of Cheml.tryVol. 1M, December 1976, pp. 988-990Complexes of Organic Arsonic Acids: Part VIII - Complexes ofV02+ & Cu2+ with Arylarsonic AcidsS. S. SANDHU, B. S. MANHAS & G. K. SANDHUDepartment of Chemistry, Guru Nanak Dev University, Amritsar 143005andH. S. KOHLIGovernment College for Women, AmritsarReceived 26 December 1975; accepted 23 April 1976Salts of arylarsonic acids of the general formula X.CsH •.AsOa-M.n.Y [where M = V02+ orCu2+, X = H,P-CH3,p-CI,p-Br,p-OCH3, o-OCH •• o-COOH, o-N02 or o-NH2; Y = H20 or C2H50Hand n has values between 0 and 3] have been prepared and characterized on the basis of elementalanalysis, magnetic data and IR and reflectance spectral studies. The AsO. group of arylarsonicacids acts as a tridentate Ugand in all the complexes. High melting points and lack of solubi-lity in common organic solvents indicate polymeric nature of the complexes. The magneticstudy suggests the presence of metal-metal interactions in some of the complexes.Square-pyramidal and distorted octahedral structures are proposed for vanadyl and coppercomplexes, respectively.COMPLEXES of Cu(II) with m sthylarsonic. acid", o-aminophenylarsonic acid- and Schiffbases3,4 having arsonic acid substituentshave been reported, but no work has been reportedon compounds of VO~+ with arylarsonic acids,In continuation of our investigations on the chemistryof arylarsonic acidso-:2 we report here the isolationand characterization of V02+ and Cu(II) complexeswith pher.ylarsonic acid (A), p-methylphenylarsollicacid (B), p-chlorophenylarsonic acid (C), p-~rol11o-phenyl arsonic acid (0), p-methoxyphnylarsoalc acid(E), o-methoxyphenylarsonic acid (F), o-carboxy-phenylarsonic acid (G) and o-nitropheaylarso:11cacid (H). A Cu(II) complex with o-arninophenyl-arsonic acid (I) has also been prepared. The com-plexes have been characterized on the basis ofelemental analysis, magnetic susceptibilities a-id IRand refiectance spectral studies.Materials and MethodsArsonic acids were prepared by the reportedmethods13,14. Vanadyl complexes of all the acids,except for the acids (G) and (H), were obtained byrefluxir.g aqueous solution of vanadyl "ulpha~e(0·01 mole) and ethanolic solution of arvlarsonicacid (0·011 mole) for 30 min, when a sky-blue p~ecl-pitate separated. Cu(II) complexes were obtainedsimilarly from copper acetate (BOH, AR) .~vhlarsonic acids using absolute ethanol as the medium.Vanadyl complexes of acids (G) and (H) were pre-pared by refluxing aqueous vanadyl sulphate solu-tion, the PH of which was adjusted to 3·5 by t~eaddition of sodium hydroxide, and the ethanolicsolution of arsonic acid till the precipitate settleddown. The complexes were purified by washingthe precipitate repeatedly with hot ethanol anddrying in vacuo.988Vanadium wa.se.:;timated gravimetrically bytreating the complex with CO:1C.HlS04 and thenigniting it in air to VzOs. Copper was determinedvolum etrically by EDT A titration.The m 19i1etic susceptibilities of the Cu(II) com-p'ex es with acids (A) and (I) were measured atdifferent temperatures (85-294°K) while those ofthe remaining complexes were measured at roomtemperature only, employing the Gouy method.The diamagnetic corrections were calculated on theb3.S~Sof Pascal's constants".Th- IR spectra of acids (A) and (I) and theircomplexes with Cu(II) were recorded in KBr on aC:trl-Zeiss URIO spectrophotometer. The IRspectra of the remaining acids and their complexeswere recorded in nujo: on a Hilger and Watts H.800spectrophotometer. The refiectance spectra of thecomplexes were recorded on a Unicam SP 700 Aspectrophotometer having SP 735 diffuse reflectanceattachment (range: 50,000-4000 crrr").Results and DiscussionThe analytical data (Table 1) show that the aryl-arsonates may be represented by the general formulaX,C6H~.\~03.~I.nH20, where M=V02+ or Cu1+;n=0·5, 1·5. 2·0, 2·5 O~· 3 and X=H, P-CH3' p-Cl,p-Br, P-O:::H3' o-OCH3• o-COOH, o-N02 or o-NH2except [0, vanadyl o-nitropheaylarsonate, whichanalyse I t,)[ 02~,C6H4.\s03.VO.1/2 C2HsOH. Thehigh melting points and insolubility ill organicsolvents suggest a polymeric nature for the complexes.The bands due to v-OH (ref. 16), present around2750 and 2250 crn! in the 1R spectra of acids weremissin ~ in the sp actra of all the complexes+, in-dicating dibasic nature of the acids. This conclusion*Detailed IR data can be had from the authors on request.SA);DHU et al.: CO~lPLEXES OF ARYLARSONIC ACIDST.\BLE 1- ANALYTICAL AND :llAGNETIC SUSCEPTIBILITY DATA OF THE COMPLEXESSalt Calc. (%) Found (%)t fLeff(BM)C H Metal C H :lletal·C6H.As03·VO·2H.0 23·76 2·97 16·86 23·55 2·95 16·02 1·77p-CH3·C6H.As03·\·0.3i2H2O 27·27 3·24 16·55 27·04 3·29 16·12 1·76p-CI.C.H.As03.V O.Hp 22·53 1·88 15·96 22·01 2·34 15·27 1·79p-Br.C .H.As03.VO.?H.0 18·85 2·09 13·36 19·05 208 13·10 1·79p-OCH .C6H.As03.\ 0.3H2O 23·93 3·70 14·53 24'01 2·78 14·02 1·77o-OCH;C6R.As03.VO.H.0 26·67 2·86 16·15 26·80 2·84 15·91 1·76o-COOH ..C6H.As03·VO.5/2H.O 23-60 2·81 14·33 23·16 2·01 13-94 1·74o-~02·C.H.As03·VO.1/2.C2H50H* 25·08 2·09 25'20 2·04 0·76C6H5As03'Cu 27·34 1·90 24·00 27·84 2·24 23·7 1·78p-CH3.C6H.As03.Cu.l j2H2O 29·32 2·79 22·18 29·27 2·78 22-4 1·89p-CI.C6H.As03.Cu* 24·16 1·34 21·32 24·16 1·50 20·9 1·73p-Br.C6H.As03·Cu* 21·03 H7 18·56 21·57 1·36 18·3 1·71p-OCH3·C6H.As03.C" 28·63 2·72 21·65 28·83 2·56 21·4 1·71o-COOH.C6H.As03• Cu. 3/2H 20 25·12 2·39 19·00 25·11 2·52 19·3 2·10o-N02·C6H.As03·Cu* 23·33 1-62 20·60 23·16 1·83 20·8 1·80O-~H2,C6H4AsO".Cu* 25·71 2·14 22·60 26·04 2·58 22·8 1·93O-OCH3,C6H.As03·Cu.H.0 26·97 2·89 20·40 27·28 2·78 20·5 1·86*Satisfactory halogen analyses have been obtained.tEstimations of C, H, ~ and halogens were carried out by the Australian Microanalvtical Service, Melbourne,is further supported by the changes in symmetricand asymmetric stretches of AsOi- grOJp17 0:1 com-plex formation. In the spectrum of the coppercomplexes of acid (A), in addition to a banell8 at460 cnr? due to phenyl ring, two more bands at520 and 475 crrr ' appear. Similarly, in the spec-trum of the copper complex of acid (I), in additionto phenyl ring bandsI8 at 550 and 465 crrr-. a 1 addi-tional band appears at 475 crrr". These additionalbands may be assigned!" to 'ICU-O. The -".s=Obands'? clearly shift downward in the vanadylcomplexes of the acids (A), (E) and (H) and thecopper complexes of the acids (A) to (F). In thecase of vanadyl complexes of acids (C), (D) a1d (F)and copper complexes of acids (G) and (H) the down-ward shifted As=O bauds arc, however, not dis-tinctly visible as these overlap with the band dueto asymmetric stretch of --\,>01". This downwardshift suggests the bonding of metal ions to Ox.ygeHatoms of A5=0 group also, In vanadyl complexesof the acids (B) and (G) and copper complex of theacid (I), the A5=0 bands, instead of shifting down-ward, register a shift to higher frequency region.This upward shift may result fr0111the coupling ofarsenic-oxygen and metal-oxygen stretching modeson coordination of '\s=O oxygen to metal ion.The coordination through oxygen of A5=0 gr.np ISalso supported by the variation in 'I'\,,=C (aromatic)(ref. 17) on complex formation. In view of the pre-ceding observations, a tridentate nature of thearsonic acids is indicated in all the complexes.The increase in symmetric and asymmetric fre-quencies of H3C-0-C (aromatic) group in thecomplexes of o-methoxyphenylarsonic acid mayarise from the involvement of -OCRl group incoordination with the metal ions. The band at3310 crrr" due to -:JH2 group in the spectrum ofo-aminophenylarsonic acid undergoes a downwardshift of 210 cm! in copper complex which suggeststhe coordination of nitrogen to the metal iO:1. Thissuggestion is further supported by the variationin other band" of -NH2 group of the acid. Thepresence of bands'? due to O-R stretch, -ORdeformation and C-O stretch at almost samepositions in the spectra of o-carboxyphenylarsonicacid and its complexes supports the non-involve-ment of the OH of carboxyl group in complex forma-tion. A doublet at 1650, 1637 cm! due to C=O ofthe carboxyl group shifts to 1585, 1550, 1535 crrr" inthe copper complex, suggesting coordination ofc=o oxygen to the copper ion20•The magnetic moments of vanadyl complexes,except for the complex of o-uitrophenylarsonic acid,are in the range of 1·74-1·79 B),'l and are almostequal to the spin-only value expected for the VOHsystem. In the reflectance spectra of the vanadylcomplexes, only two bands were observed in theranges 16,000-1+,000 and 11,200-10,400 crrr '. How-ever, when the spectrum of o-methoxyphenyl-arsenate recorde.l after mixing the complexwith freshly prepared magnesium oxide powder, itshowed an additional band, though of weak in-tensity, at 25,000 crrr". Thus, reflectance spectralstudy suggests a square-pyramidal." stereochemistryaround vanadium. The very low value of magneticmoment (0·76 B"y1:) observed in o-nitrophenyI-arson ate may be due to interaction between unpairedspins in the 3dxv orbitals of vanadium= atoms,The magnetic moment values measured at roomtemperature for the copper complexes with acids(B) to (F) and (H) were found in the range 1·71-1·89 K\1: indicating octahedral stereochemistryt".The magnetic moment values of copper complexeswith acids (A) and (I) at different temperatures(85-294°K) were found in the ranges 1·37-1·78 and1·70-1·93 EM respectively. The decreased mag-netic moments at lower temperatures mav be due toincreased spin-spin interaction. This effect is consi-derably reduced in the complex with acid (I) dueto additional coordination of amino group' with989INDIAN J. CHEM., VOL. 14A, DECEMBER 1976copper ion. A magnetic moment value of 2·1 BMfor copper complex with acid (G) is higher than thatexpected for an octahedral complex. However,the presence of a broad band with a maximumaround 11,000 crrr" and a band near the IR regionin the reflectance spectra of all the copper complexessuggests a distorted octahedral stereochemistry= forcopper in this and other complexes.AcknowledgementThanks are due to Prof. R. D. Dua, lIT, NewDelhi, for providing facilities for IR and reflectancespectral studies.Referencesi. GILLET, J., HUYGE-TrPREZ, G., KrCOLE, J. & TRIDOT, G.,C.R. Acad. Sci. Ser., C 273 (1971), 1743.2. MASLENNIKOVA,1. S. & SHEMYAKIK, Y. N., Zh. fie.,Khim., 46 (1972), 1004.3. BASATO,M. & PELOSO, A., Gazz. chim, ital., 101 (1971),28t.4. SANDHU, S. S. & SANDHU, G. K., Indian J. Chem., 12(1974), 830.5. SANDHU, S. S., MANHAS,B. S. & KOHLI, H. S., h1dianJ. Chem., (accepted).6. SANDHU, S. S. & SANDHU, G. K., J. iuorg, nucl, Chem.,34 (1972). 2249.7. SANDHU, S. S., MANHAS,B. S. & KOHLI, H. S., IndianJ. Chem., 11 (1973), 197.9908. SANDHU, S. S. & AULAKH, G. S., Indian]. ci-«. 11(1973), 46.9. SANDHU, S. S. & AULAKH, G. S., Indian]. Chem., 13(1975), 281.10. SANDHU, S. S., KAUR, J. & SANDHU, G. I{., Syn, React.Lnorg, metal-argo Chem., 4 (1974), 437.11. SANDHU, S. S. & AULAKH, G. S., Indian J. Chem., 13(1975), 518.12. SAKDHU, S. S., MANHAS,B. S. & KOHLI, H. S., IndianJ. Chern., (accepted).13. VOGEL, A. 1., Practical organic chemistry (Longmans,London), 1962.14. BLICKE, F. F. & 'WEBSTER,G. L., J. Am. chem, Soc., 59(1937), 534.15. PRASAD, M. & MULAY, L. N., J. chem, Phys., 20 (1952),20l.16. HENRY, M. c.. Tnorg, cu«, 1 (1962), 917.17. DIETZE, D., J. prakt. Chem., 313 (1971), 889.18. BENTLEY, F. F., SMITHSON,L. D. & ROZEK, A. L., Infra-red spectra and characteristic frequencies, 700-300 cm-1(Interscience, London), 1968.19. RODLEY, G. A., GOODGAME,D. M. L. & COTTON,F. A.,J. chem . Soc., (1965), 1499.20. 1.,YLOR, M. D., CARTER,C. P. & WYKTER, C. 1., J. inorg,1111Cl. ci-«. 30 (1968), 1503.21. DUTTA, R. L. & LAHlRY, S., J. Indian chem . Soc., 40(1963), 857.22. GIKSBERG,A. P., KOt.'BEK, E. & V;ILLIAMS,H. J., Tnorg:Cheni., 5 (1966), 1656.23. FIGGIS, B. N. & LEWIS, J., Progress ill inorganic chemis-try, Vol. 6, edited by F. A. Cotten (Interscience, NewYork), 1964.24. LEVER, A. B. P., Inorganic electronic spectroscopy (Else-vier, Kew York), 1968.

Complexes of Organic Arsonic Acids: Part VIII - Complexes of VO2+ & Cu2+ with Arylarsonic Acids

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Complexes of Organic Arsonic Acids: Part VIII - Complexes of VO2+ & Cu2+ with Arylarsonic Acids

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