Das, P. N. Mohan

Diemert, K.

Kuchen, W.

English

NOPR

IndianJournal of ChemistryVoL 15A.January1977,pp.29-32MetalComplexesof PhosphinicAcids: PartXIII*-DithiophosphinicAcid Complexesof U02(VI) & In(III)P. N~MOHAN DAS, K. DIEMERT & W. KUCHENtInstitutfur AnorganischeChemie,UniversitatDusseldorf,Universitatsstr1,4000Dusseldorf,WestGermanyReceived10May 1976;accepted5 June 1976U02(VI) and In(III) complexesof dimethyldithiophosphinicacidandthe In(I1I)-complexof p-methoxyphenyl-methYldithiophosphinicac d havebeenprepared.Their propertiesandstructureshavebeenstudiedusin~elementalanalysis,molecularwei~htdeterminations,IR,UV,mass,nmr,ma~neticstudies,thermalanalysisetc. It is foundthatthesecomplexeshavin~theformulaInLsandUOaLs(whereL is a deprotonatedbidentateli~andmolecule)formneutralcomplexesto whichoctahedralstructureshaveteenassi~ned.The stabilityconstantsof theuranylcomplexhavebeendeterminedpotentiometricallyin 20%dioxan-watermediumat anionicstren~thof 0'2Ms(KNOs)' Lo~~avaluesis foundto be5,58.DIPHENYLDITHIOPHOSPHINIC acid hasbeenused as a complexingagentby manyworkersl-7. Kuchen et al.8-1ohavereportedthestudiesof themetalcomplexesof dialkyldithio-phosphinicacids. Metal complexesof p-methoxy-phenyl-methyldithiophosphinicacid havebeenin-vestigatedby Diemertu.A surveyof theliteratureshowsthat the UOa(VI) and In(III) complexesofdimethyldithiophosphinica id (dmdtp)and In(III)complexofp",methoxyphenyl-methyldithiophophinicacid(mpmdtp)havenotbeenstudied. Thispromptedus to prepareand characterizeU02(VI) andIn(III)complexesofdmdtpandIn (III) complexofmpmdtp.The stability constantsof the U02-dmdtpcomplexhave also been determinedin 20% dioxan-watermedium.MaterialsandMethodsAll thechemicalsusedwereof AR grade. Sodiumsaltsof theligands,(CHa)2PS2Na.2H20(ref.12)and(P-CHaOCeH4)CHaPS2Na.2H20(ref. 13) werepre-pared as describedin the literature. Dimethyldi-thiophosphinicadd [(CHa)2P(S)SH]was preparedfrom the sodiumsalt as follows:Dry HCI gaswasbubbledfor 4 hr througha sus-pensionof thesodiumsalt (20g) in absolutedioxan(200ml) at 0°. NaCI that precipitatedout wasfilteredoff, the filtrateconcentratedunderreducedpressureandtheacidprecipitatedby theadditionofabsoluteether. The white crystals formedwerewashedwith etheranddriedin vacuum,m.p.48-50°(lit.!' m.p.47-50°).Preparationof thecomplexes:U()?(dmdtpb- Con-centratedaqueousolutionsofuranylnitrateandthesodiumsaltofdmdtpweremixedin themolarratioofI: 3 andwarmedat 50°to 60°,for a fewminutes.The solutionwhich turnedred was repeatedlyex-tracted with small portions of ether. The etherextract was dried (anhyd. MgS04), concentrated*Part XII, P. N. MohanDas,W. Kuchen,H. Keck &G. Hagele,J. inorg. nucl. Chem.,39 (1977),tAuthorto whomall correspondencemay be addressed.underreducedpressureand allrwedto crystallize.The reddishyellow crystals separatedout werefiltered,washedwith etherand driedeverP?05inhighvacuumat 85°. Thedry crystalswerebrownishyellowin colour,yield :::::60%..In(dmdtphand In (mpmdtp)a-Aquecussclutionsof In(III) chlorideand sodiumsalt of the ligandweremixedin themolarratioof 1: 3,withcontinuoU!'1stirring. Whiteprecipitate,appearedinstantaneously.wasfilteredandwashedwellwith water. For puri-ficationIn(dmdtP)awas recrystallizedfrom chloro-form and In(mpmdtP)awas precipitatedfrom ari.acetonesolution by the addition of ether. Bethwerewhitecrystallinepowders;yield :::::75%.Determinationofstabilityconstants- ThefollowingsolutionswerepreparedandtitratedagainststandardNaOH solution:(i)0'2mlof0·168MHCl04+10mlofl'OM KN03; (ii) solution (i)+25 ml of SX10-3MdmdtpH;and (iii) solution (ii)+5 ml of 5x lo-aMuranyl nitrate. The total volumein all the caseswasadjustedto 50mlwithdioxanandwatersothatthe mediumcontained20% dkxa~ (vJv). ThepHvalue correctiensweredeneas describedby VanUitert and Haas1/;.Physical measurement- Elementalanalysisweredone accordingtc the usual methods. Molecularweightsweredete)minedusing a vapourpressureosmometer(Knauer,Berlin), in chloroformat dif-ferentconcentratiens.VisibleandUV spectrawererecordedon a BeckmanDK-2A spectrophotometeragainstsolventasblank. IR spectra(asKBr pellets),massspectraand IH NMR spectrawererecordedona Perkin-Elmermodel521IR spectrophotometer,a Varian MAT model 311 A massspectrometer,introducingthesamplesthroughadirectinletsystem,and a Bruker HX-60 spectrometerat 60 MHz (indeuterosolventscontaininginternal tetramethyl-silaneas reference)respectively.Magneticstudies(Gouymethod)weredoneusinga Bruker-PhysikAGmagnetB-E lOin combinationwjtha Sartoriusmicro-balance4107. A MettlerthermoanalyserT A-I wasused for thermal studies. Potentiometricstudies292929·08CT4193'22CT6152·13CT11470·41CT896'86114991'48CTINDIAN J. CHEM., VOL. 15A, JANUARY 1977+.[(CH312PS2]31nlm/e490)-"H"2PS2J~ -IeH,,2PS·1 ~"2PS;(CH312PS; [(CH312PS2J2InS+ =.4 [lCH312PS2J21n+(m/e12S) (m/e3971 (m/e36S)-5 1 LIeH"2PS;Energy(kK)24·752543,57336·982243·29030·487848,7805Wavelength(nm)404,0229·5270·4231·0328·0205·0TAElLE 1- VISIBLE AND UV SPECTRAL DATA OF THECOMPLEXESIn (mpmdtp).Scheme1- Fragmentationpattern of In[(CHa).PS.Ja[ L:(CH30C6H/,ICH3PSi']Scheme2 - Fragmentation pattern of In[(p-CHaOCaH4)CHaPS.Ja(CH3)2PS+ OCH3)2PS2]ln+'lm/e 9Jl(m/e2401-C2H/,!~H' 1-ICH3)2PSiH PS+PS+102(m/e6S1(m/e63)(m/el1S)1 -L'In+(m/ellS)In 1.+'(m/e33ZI1 -L+rnL2(m/e5/,91:t-LZlns ~{m/eS81JlnLj'lm/e766 I1-s-lnl'-2-Y~+.(CH30C6H/,ICH3PSZH(m/eZ161l-SH' ~S'21-t- 1+ICH30C6H/,ICH3PS (CH30C6H4)CH2(m/e18SJ (m/e121):Ii-ICH30C6H41CH3P(m/e 153)got depositedfromthe complexduringthe studies.Themassspectraldataof theIn complexesindicatethat thebasepeaksin thespectraof thecomplexesaredueto the very stable ion Mq (L=dmdtp ormpmdtpmolecule)resultingfrom the radical eli-minationof oneL· fromthe molecularion. Otherstrongpeaksobservedare givenby the fragments(CH3hPSt and In+ in In(dmdtp)a while by(CH30C6H4)CH3PS+in In(mpmdtp)a.The frag-mentation patterns are shown in Scheme31and2.Magneticmeasurements- Thesestudiesshowthatall thecomplexesarediamagneticin naturewhichisin agreementwiththeU(VI) (5r) andIn(III) (4d10)onewithaMetrohmTitriskopE 516pH meterombinedelectrodes.Res ts and D~scussionUr nyl complexis readily soluble in commonorg ic solventslike methanol,ethanol,dioxan,chlor.form,etc. Indiumcomplexesareeasilysolubleinho chloroform,dioxan,benzene,etc.,butsparinglysolube in ethanol,ether,carbontetrachloride,etc.Uran 1 complexon heatingchangedcolourslowlyfrom yellowto red, brown and finally black anddeco posedabove240°. In(dmdtp)aturnedto paleyello colouronheatingandmeltedat212-13°.TheIn(m mdtp)ameltedat 167-68°.Th elementalanalysisdata are given below:U02( mdtph (Found:C, 11·58;H, 2'62;S, 24·41:P, 1 ·34. Required:C, 9·23;H, 2·3; S, 24·65;P,11'9110). The analysisfor carbonwasalwayshighby 1 %. In(dmdtp)a(Found:C, 14'47;H, 3·65;S,38,91;P, 18·40;In, 23·16. Required:C, 14·69;H,3'67;S,39,25;P, 18'96;In, 23'42%). In(mpmdtp)a(Fou d: C, 38·35;H, 4,06;S, 25'30;P, 11,66;In,14·6 Required:C,37'5;H, 3'92;S,25,12;P, 12·13;In, 1.'98%).Th molecularweightsofU02(dmdtph,In(dmdtp)aand (mpmdtp)awereindependentof theconcentra-tionsemployedandwere551,494and772againsttheo tical valuesof 520,0,490·1and766,0respec-tivel ,indicatingabsenceof molecularassociationordissoiation.IR spectra- The IR spectra"of the complexe"and e ligandsshowfollowingsignificantfeatures:The eakbandat 2360in dmdtpHandthebroadmedimbandat2260-2320in mpmdtpHdueto vS-Hdisa earin the complexeshowingthe absenceoffree -H group. Thestrongbandsat450and580indmd H areshiftedto 495and590in U02(VI) andto 48 and585in In(III) complexeswhile thoseat 5 and600in mpmdtpHshiftto 520and598inIn(II ) complex. In the caseof dmdtpcomplexesthev -S areseenat385and410in U02 complexandat 29 in In complex. The strongbandat 922 inthe seof U02(VI)-dmdtpmaybe assignedto theV3 of heU-0 group16.ThevisibleandUV spectraldataof thecomplexesaregivenin Table1.M ssspectrat- Themasspectrumoftheuraniumcomlex couldnot berecordedaselementalsulphurCT = chargetransfer.*V~X values in em-I.tFo detailed IR and mass spectra contact the Seniorautho Prof. W. Kuchen.30I I31SOIl400-- -!.-;,::. ~·'C.B'.... ".--.••-- -----..:":i ..200100log K~=log_nH +pHnH_lIncIclIherm408012020406080100300TEMP. f'CFig. 1- DTA andTG profiles[(A) Studiesof UO.(dmdtp).inair; (B)studiesof U02(dmdtp)..1 H.o in air and impurenitrogen;and(C)studiesofU02(dmdtp)2inpurenitrogenandin highvacuum]Obviouslythereis an uptakeof oxygenby··theuraniumcomplexatelevatedtemperatures,ofar asnotobservedin otherdithiophosphinatesinvestigatedby us. The natureof the reactionin which thesulphurin the ligandseemsto be exchangedforoxygenisnotyetclear.In(dmdtphonheatingat a rateof 4°/minin nitro-genatmosphereremainedconstantin weightup to213°,thenmeltedandupto380°,70'0%oftheweightwaslost. Theweightwaspracticallyconstantfrom380°to 500°. The completedestructionof thecom-plexmightbetakingplacefrom213°to 380°.TG experimenton In(mpmdtp)ashowedconstantweightup to 290°with a meltingpoint of 167°andthenthe lossof weighttook placein threestages,from290°to370°=23%,370°t04400=17%andupto500°=7%dueto thethermaldecompositionof thecomplex.Stabilityconstants- For stabilityconstantdeter-minationstheligandsolutionsweretitrated againststandardNaOHsolutionin theabsenceandpresenceofthemetalionsat20°±0·1°C,[.1.=0,2(KNOa). Theaciddissociationconstantof theligand(CHahPS2H.(dmdtpH)wasdeterminedby themethodof Irvingand Rossotti17• Formationcurvefor proton-ligandsystemwasdrawnbetweennHandpH,wherenHistheaveragenumberof protonsattachedper ligandmolecule.ThepK valuewasdirectlyread.fromtheformationcurve. It was alsocalculatedusingtheequationMOHAN DAS et al.: DITHIOPHOSPHINIC ACID COMPLEXES OF U02(VI) & In(III)ions. The diamagnetismof In(dmdtp)a and 160In(mpmdtp)awerefoundto be -199·49x10-6cm3mole-1at 292K and -473·72X 10-6cm3mole-1at294·4Krespectively.NMR spectra- The IH NMR spectraof all thesecomplexeshowedthe expectedsignals. For theU02(dmdtp)2and In(dmdtp)acomplexesdoubletsdue to proton-phosphoruscoupling(2JpCH~13Hz)areobserved.The8valueswerefoundtobe2·25ppm(CHCla)and2,15ppm(CDaCOCD3)for U02 andIn VlVI 0complexes respectively while 8=2·12 ppm.(CDaCOCDa)for (CH3)2PS2H.A non-equivalenceofthe methylgroupscouldnot be detectedin thistemperatureregion. The In (mpmdtp)3showedinthearomaticregionthecomplexsignalsof a [AM]2X 10systemsimilarto the pure ligandabsorptiondis- C'/OM) 0cussedelsewhere13•All the absorptions3.,1100=7.9ppm,80CH3=3'8ppm,8meta=6·9ppm,and8cHa=2'4ppm,areonlyslightlyshifted.Thermalbehaviour- It wasobservedthatthedryuraniumcomplexon keepingin contactwith mois-ture absorbedwatergivingred crystalswhich onheatingat 90° in vacuogaveback the brownishyellow crystals. The numberof water moleculesabsorbedwasfoundtobeonebylossofweight(3·53%)on thoroughlydrying at 95° over P206• Loss ofweight on TG experimentupto 1500~3%.Thetheoreticallossof weightfor onewatermoleculeis3·46%,On continuousexposureto highly humid at-mosphereforafewweeks,theseredcrystalsabsorbedonemorewatermoleculewhichwasdeterminedbyTG (Lossofwt foundup to 150°=6·3%.Theoreti-~alwt for 2 watermolecules=6·47%).A combinedTG/DTA experimentof the mono-hydratedand the water-freeform of the uranylcomplexestablisheda remarkableinfluenceof thei:lxperimentalconditionson its thermalbehaviour.In an atmosphereof flowingnitrogencontainingtracesof oxygenandat aheatingrateof 2°/mintheTG curve (Fig. lB) showeda weight loss of 3%between80°and160°whichisanendothermicprocess,dueto thelossof onewatermoleculein the caseofthemonohydratedform. With increasingtempera-turestherewasanincreasein weightof about4·5%withreferencetotheinitialweight. Thiswasastrongi:lxothermicreaction as shown by DTA (Fig. 1).Therewasno furtherincreasein weightafterabout220°andthenthenormalthermaldegradationprocessstarted (220-320":weight loss=3'0%; 320-420°:weightloss=15·0%).Theproductaftertheexother-micreactionupto220°showednoP-Sabsorptionbandsin theIR spectrumbut anewverystrongandbroadbandappearedat 1070-1090,possiblydueto vP-O.Experimentsunderhighvacuum(10-4-10-5mmHg)and in an atmosphereof extremelypure nitrogenshowedno exothermicreactionat this range. Thecomplexwasstableupto200°andthisproductshowedall theIR absorptionbandsof theoriginaldry com-plex. An exothermicreaction with increaseinweightin this temperaturerange,similarto thatmentionedabove,was observedwhenthis experi-mentwas doneunderflowingair. A changefromaluminiumto aluminiumoxidecrucibledidnothave.anyeffectonthenatureof thereaction.INDIAN J. CHEM., VOL. 15A, JANUARY 1977The veragepK valueof dmdtpHwasfoundto be2·79' 20%dioxan-watermedium.Th ligandneutralizesoneequivalentof thebaseto y' ld one buffer regionin the potentiometrictitraton curveindicatingits monobasicnature. Afall .. pH wasobservedonaddingtheuranylnitratesolutin to theligand,whichindicatedtheformationof a C mplex. Duringtitrationthemetalhydroxidegot ecipitatedat pH~4·7.Th formationcurvefor the metal-ligandsystemwas rawnbetweenn andpA, thevaluesof whichwerecalculatedby the methodof Irving andRos-sotti1.R !.S"""'P/"'-MR'/ ~'S/IlogKl andlogK2 valuesweredirectlyreadfromthef ationcurveat n=0·5and 1·5. ThelogK}>log andlog ~2 valueswerefoundto be 2'82,2·75and558±0·01respectively.As therewasnotmuchdifferncebetweenthelogKl andlogK2 values,noothermethodswereappliedfor therefinementof thevalue. As a comparativestudy of the stabilitieswasn t in ourpresentinterests,wedidnotcarryoutthe ability constantdeterminationsof the Incompexes.Fr thesedatait is clearthattheU02(VI) forms1:2 omplexU02[(CHshPS2]2 and In(III) formscompexesof the type MLs whereL is a dmdtpormpmtp molecule.The bondingnature is shownin st cture (I).In all thesecasesoctahedralstructurescan beassied to the complexes,the 0= U=0 groupinthe uaniumcompoundlying perpendicularto theplane ontainingthe4sulphuratom,;oftheligand18•32AcknowledgementWe wish to expressour heartythanksto Dr H.ReckandMr H. Karrasforrunningthemassspectraandto Mr A. Mundt for carryingout the thermalanalysis.Reterences1. KUCHEN, W., METTEN, J. & JUDAT, A., Chern.Ber., 97(1964),2306.2. KUCHEN,W. & MAYATEPEK,H., Chern.Ber., 101 (1968),3454.3. MUKHERJEE, R. N., SHANBHAG,S. V., VENKETESHAN,M. S. & ZINGDE,M. D., Indian J. Chern.,11 (1973),1066.4. MUKHERJEE,R. N., SONSALE,A. Y. & GUPTA,J., IndianJ. Chern.,4 (1966),500.5. MULLER,A., KRISHNARAo, V. V. & DIEMANN,E., Chern.Ber., 104 (1971),461.6. MULLER,A., KRISHNARAO,V. V. & KLINSIEK, G., Chem.Ber., 104 (1971),1892.7. CAVELL, R. G., DAY, E. D., BYERS, W. & \VATKINS,P. M., Inorg. Chem.,11 (1972).1591.8. KUCHEN, W. & JUDAT, A., Chem. Ber., 100 (1967),991.9. DIEMERT, K. & KUCHEN, W., Chem.Ber., 104 (1971),2592.10. KUCHEN, \V. et aI. (unpublishedresults).11. DIEMERT, K., Doctoral dissertation,Universitat Dussel-dorf, 1972.12. CAVELL,R. G., BYERS, W. & DAY, E. D., Inorg. Chem.,10 (1971),2710.13. HAEGELE, G., DIEMERT, K. & KUCHEN, W., Z. Natur-·forseh., 28b (1973),185.14. MASTALERZ,P., Roezniki Chem.,34 (1960),1161.15. VAN UITERT, L. G. & HAAS, C. G., J. Am. ehem.Soc.,75 (1953).451. .16. CONN,C. K. T. & Wu, C. K., Trans. Faraday Soc., 34(1938),1483.17. IRVING, H. & ROSSOTTI,H. S., J. chem.Soc., (1954),2904.18. BIRDAR,N. S., PATIL, M. D. & GOUDAR,T. G., J. inorg.nucl. Chern.,37 (1975),1437.

Metal Complexes of Phosphinic Acids: Part XIII*-Dithiophosphinic Acid Complexes of UO2(VI) & In(III)

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Metal Complexes of Phosphinic Acids: Part XIII*-Dithiophosphinic Acid Complexes of UO2(VI) & In(III)

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