Biradar, N. S.

Hosmane, N. S.

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NOTES]IIThe Schiff baseswere preparedfrom reagentgradechemicalsaccordingto the methodreportede1sewhere4and dried in vacuoover phosphorouspentoxidebeforeuse.All the manipulationsweredonein a partiallyevacuated ry-boxunderoxygen-freenitrogen.The complexeswere preparedas follows: Asolutionof silicontetrachloridesuperdry benzeneswas treatedwith a slight excessof Schiff basedissolvedin the samesolventand left for severalhourswith occasionalshakingat roomtemperature.Sufficienttime was allowedfor the precipitatetosettle. The complexwasfiltered,washedfreefromthe reagentwith benzeneand dried in vacuooverfusedcalciumchloride.The data in Table 1 show that silicon tetra-chlorideforms adductswith all the Schiff basesemployed.The Schiff basesIa-d form adductsof1: 4 stoichiometrywhereas IIa and lIb formadductsof 1:2 stoichiometry.All theseadductsare dark coloured,hygroscopicsubstances,solublein acetonitrile,DMF and DMSO. Theseundergohydrolysisreadilyin water.The molarconductancevaluesin purifiedaceto-nitrile5 (concentration10-3M) fall in the range31-62 ohm-I cm2fmole,indicating non-electrolytenature of the complexesin acetonitrile.Molarconductanceof 1:1 electrolytein acetonitrile6fallsin the range 190-195 ohm-l cm2fmole.The lowconductanceobservedmay be due to the partialsolvolysisof the complexesin acetonitrile.Some adducts with o-hydroxyazomethinesaredocumentedin theliterature,especiallywithSn(IV),Ti(IV) and Si(IV). In view of these evidencesit may be consideredthat presentlysynthesizedcomplexesare also adducts,and not substitutioncomplexesinvolvingo-hydroxygroupof the Schiffbasesin whichcasea moleculeof hydrogenchlorideliberatedwould have attachedwith azomethenenitrogento give1:1electrolytes.Furthersupporttothisconjectureis providedby theIR datain nujol.The broadweakbandsin the Schiffbasesin theregion2800-2600cm-lareretainedin thecorrespond-ing complexes.The coordinationthroughnitrogenshould either weakenthe strengthof H-bondingor allow the formation of H-bonding with the7t-systemof the azomethinegroup. The bond dueto phenolicC-O in the region1289-1272cm-linthe Schiff basesdoesnot showany shift towardsthehigherfrequencyregionin thecomplexes.Theseobservationsuggestthat the o-hydroxygroup ofthe Schiff basesIa-d and IIa, b, is not involvedin the bond formation.Ita=Hb=CH3c~ctd =OCH3Schiffbasesderivedfromsalicylaldehydeandaniline,p-to1uidine,p-chloroanilineandp-anisidinereactwithsilicon(IV)chloridein dry benzenemediumto formtheadductsof thetype(SB),SiCI"whereasthe Schiffbasesderivedfromsalicylaldehydeando-vanillinwithp-aminodiphenylamineform the adductsof thetype(SB').SiCI,. Thesehy~roscopic,olouredadductsbe-haveasnon-electrolytesin acetonitrile.The infraredspectralstudyrevealsthat coordinationhas takenplacethrou~hthe azomethinenitro~en.It appearsthat silicon exhibitscoordination umber ei~htin(SB),SiCI«typeofcomplexesandsix in (SB').SiCI,.Received2 July 1976; accepted7 February 1977N. S. BIRADAR*& N. S. HOSMANEDepartmentof Chemistry,Karnatak UniversityDharwar 580003Si(IV) Complexeswith SchiffBases13. RYAN, J. L. & JORGENSEN,C. K., Malec. Phys., 7(1963),17.14. MILES, J. H., J. inorg.nucl. Chem.,27 (1965),1595.15. BARNES,J. C. & DAY, P., J. chem.Soc., (1964),3886.THE vast amountof literature addedto thegrowthof understandingthe natureof silicon-nitrogenbondsin the complexesof silicon(IV) ismainlydueto Wannagatandcoworkersl.Recently,Paul and coworkers2have reporteda few Si(IV)complexeswith nitrogendonor ligands. However,the limited literatureknown on silicon(IV) Schiffbasecomplexes3has promptedus to undertakeasystematicstudy of silicon(IV) complexeswithSchiff basesof types (I) and (II) derivedfromsalicylaldehydeand aniline (Ia), p-toluidine(Ib),p-chloroaniline(Ie) and p-anisidine(Id) and p-aminodiphenylamine(IIa) and o-vanillinand p-aminodiphenylamine(lIb).TABLE 1- PHYSICAL PROPERTIESAND ANALYSIS OF SILICON(IV) SCHIFF BASE COMPLEXES[Silicon estimatedas SiO.]SlEmpirical formula Si(%)N(%)Cl(%)ColourNo. FoundCalc.Found1(C13HnNO)«SiCl, 2'912·925'245,8514-8014·82Orange24 13NO),SiCl, ·8876,56·001do3O C1),SiCl, 56· 992 98Yell wish green4.),SiCl« 776 3 4-17do59 . . i , 3,63 47'4 ' 69 4Brownis black6'O .0.). l, 2786 57*For correspondence.659.----------~pI~EPARATION andstructuresof severalorganoantimonycompoundshave beendescribedinliterature1-G• Results obtainedfrom the reactionbetweenstannicchlorideor organotinchlorideswithorganicchelatingligands7promptedus to preparesimilarantimonycompounds.Preparationswerecarriedoutusingabsolutelydrysolventsunder moisture-freeconditions;filtrationsweredoneusinga positivepressureof dry nitrogengas.Tris(salicylald.:hydato)antimony(III)-- Antimonytrichloride (2,28 g; 0·01 mole) was dissolvedinbenzene(50mI)anelreactedwithsodio-derivativeofsalicylaldehyde(0·04 mole; preparedvia sodiummethoxide)by retIuxingfor 2 hr. The reactionmixturewasconcentrated,sodiumchlorideandtheexcessodio-salicylaldehydefilteredoff, andremain-ing benzeneremovedunderreducedpressure.Theproduct was washed with hexane and solventremovedunderreducedpressure.The yellowpro-duct,m.p.180°,weighed4·36g (90% yield)[Found:Sb, 25·10;C, 52·01; H, 3·12. Calc.for C21H150GSb:Sb, 25,11; C, 51'96; H, 3·09%]. Molecularweight:(1) by ebullioscopyin benzene,490 and (2) bydifferentialvapourpressuremethod,482; calc.485.8-Hydroxyquinolino)antimonytetrachloride- Anti-mony pentachloride(2·99 g; 0·01 mole) and 8-hydroxyquinoline(1045g; 0·01 mole)weremixedincarbontetrachloride(50 ml) and refluxedfor 2 hrto removeall HCl. Thesolventwasremovedunderreducedpressure,the productwashedwith hexaneand dried in vacuo. The orangehygroscopicsolid,insoluble in benzene,m.p. 170°, weighed3,3 g(80% yield) [Found:Sb, 29·75; el, 34·67; C, 26·66;H, 1·26. Calc. for C9HGONSbCI4: Sb, 29·80; el,34·74; C, 26·47; H, 1·20%J.(TriPhenyl)antimonydibromide- It was obtainedas a white cryst3.11inepowderby the action ofbromineon (triphenyl)antimonyin glacial aceticacid; it wasrecrystallizedfrombenzeneas needles,m.p. 216° (ref. 8) [Found: Sb, 23·93; C, 42·42;H, 3·01; Br, 31·07. Calc. for C1SH15SbBr2: Sb,23·75; C, 42·14; H. 2'93; Br, 31-18%J.Bis(S-hydroxyquinolino)(triPhenyl)antimony- (Tri-phenyl)antimonydibromide(5,12g; 0·01 mole)wasdissolvedin benzene(50 mI) and reactedwith thesocho-derivativeof 8-hydroxyquinoline(0·03 mole)by refluxingfor 2 hr, and the productisolatedasin the case of salicylaldehydatocomplex. Theyellow powder, soluble in benzene,m.p. 175°,weighed5·75g (90'10of theory)[Found:Sb, 19·10;C, 67·62; H, 4·01. Calc. for C36H2702N2Sb:Sb,18'99; C, 67·42; H, 4,21%1-Othercompoundswerepreparedsimilarly(Table1).In the presenceof a solvent,antimonyhalidesform unst3.bleaddition compoundswith salicyl-ChelatedAntimonyCompounds*!MRS) SARADA GOPINATHAN & C. GOPINATHAN:National ChemicalLaboratory, Poona 411008Ri!feived9 August 1976;accepted24 January 1977Mo~chelatedantimony(V)tetrachlorideshavebeenprepa~edfrom antimonypentachlorideand organicbiden$techelatingligandssalicylaldehyde,8-hydroxy-------l---~-~--~-~--_*Co¢munication No. 2050 from National ChemicalLaborajtory.INDIAN J. CHEM., VOL. 15A, JDLY 1977TheIstrongbandsappearingin the region1616- quinoline,N-benzoyl-N-phenylhydroxylamine,dehydro-1600 cb-I in the Schiff basesand attributableto acetic acid and acetoacetanilide.Bis-chelatedtri-\,C=N I appearin the region1653-1639cm-I in the phenylantimony(V)compoundshavebeen obtainedac1ductf31-4Cfable1), ind catingthatthe coordina- from triphenylantimony(V)dibromide a d sodio-tionh$ takenplacethroughtheazomethinenitrogen. derivativeofbidentateligands.Tris(salicylaldehydato)-The I assignmentof this band in the adducts5 antimony(III)has also beenprepared.The spectraland 6! (Table 1) is rather cumbersome.In these andotherpropertiesof thenewcompoundshavebeenSchiff ibasesIIa and IIb, one can expecta hand studied.due t~ ~NH. As it is a band of weak intensity,it is r4therdifficul to locatethis band3.midsthehigh ii)tensityC=N andaromaticC=C vibrations.In th$e basesa h~ghin~ensityband is .observedat 15~8cm-I and IS aSSignedto the mIxture ofC==Nland first high intensity band of aromaticC==C~ibration. In the complexes5 and 6, wenoticeidear resolutionof this band; oneappearingin the!region1626-1616cm-I and the otherin theregioni 1590-1587cm-I. The high frequencybandin theicomplexesis attributedto vC=N.Theibandaround3400cm-1in the basesIIa andIIb iSiassignedto vNH. This band in the com-plexes!5 and 6 doesnot show any split or shiftindica~ingthat NH is not involvedin coordination.The!non-electrolyticbehaviourof the complexesin acEitonitrile,the spectralobservationsand thepossibilityof coordinationnumberssix and eightJin sili~on(IV)7.smakeus believethat silicon mayassum¢coordination umbereightin thecomplexes1-4anFlcoordination umbersix in thecomplexes5and 6;One:of the authors(N.S.H.) is thankful to theCSIR,I New Delhi, for the award of a junior:resear~hf llowship.lReferefces1. WA~NAGAT, D., Adv. inorg.Chem.&> Radiochem.,6 (1964),2~5;\VANNAGAT,D., RARZIG, J., SCHMIDT, P. & SCHULZE,1\11.,Mh. Chem.,102 (1971),1817; W ANNAGAT, . &MjETER, S., Z. anorg.allg. Chem.,392 (1972),392.2. PAUt, R. c., KAPILA, B., AGGARWAL, V. K. & NARULA,S~ P., Indian]. Chem.,9 (1971),997; PAUL, R. C.,~INDSE, K. S., AHLUWALIA, S. C. & NARULA, S. P.,J~ inorg.nucl. Chem.,34 (1972),1813.3. OR~OVA' L. V., GARNOVSKII, A. D., OSIPOV, C. A. &KISHKINA, I. I., Z. obshch.Khim., 38 (1968),1850;C em.Abstr., 69 (1968),113055q4. BIR~DAR' N. S. & KULKARNI, V. R., Rev.RoumaineChim.,1 (1970),1993.5 WEI SBERGER, A. & PROSKAUER, R. S., Organ csolventste~hniquesof organicchemistry,Vol. VII (Interscience,Njew York), 1955.6. GEA~Y, W. J., Coord.Chem.Rev.,7 (1971),81.7. BEAiTIE' I. R., Q. Rev., 17 (1963),382.8. STO E, F. G. A. & SEYPERTH, DIETMER, ]. inorg. nucl.C em.,1 (1955),112; TROST, W. R., Can. ]. Chem.,3 (1952),835, 842.660I I~lllj

Si(IV) Complexes with Schiff Bases

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Si(IV) Complexes with Schiff Bases

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