STUDIES ON SOME NEW ANILS AND THEIR INTERACTION WITH LEWIS ACIDS & HEAVY METAL IONS

Abstract

From the time of Werner*1 *» 1B03, the whealstry wf aetal eoaplexee has aade such a rapid advance and has feuad application in so aany Iivereified fields that it is difficult to keep paee with the day to day aevelopaents which are being added to its existing vast and enormous ehealcal literature. Moreover the chemistry of complex c^mpoun'8 doss not csaae to exist slaply with the asntioa of reaotions of metnls with coordinating end ehelating agents, having nitrogen or oxygen and even sulphur or phos phorous m donor atoms, but finds new outlstw in structural problems t> be solved by highly complicated theories eased en quantum theory and quantum aechanioe and by ueing extrenely refined physical tools like T.R, W.H.R., S.S.R#f U.f and Raman spectra t x-ray, magnetic euseeptlbllity, aass 8peotroso> yt electron microscopy st. And then beyond this, it exhibits Its ia*my pec«lt»r yet highly faneinating facets ia anslyttoal chsmlstry beginning with precipitates ia estimating astals in voluaetrio analysis and eolorlaetry es indicator ©omplexes, finally finding support for their identity an4 stability in various electro-eheaieal aethods, eg, pH aetry, polarography, eoul>aetry, saperoaetry etc. and modern analytical techaiquee like equilibrium ditlysls, radio lsotopy, liouid-ll^niia extraction , ion exchange, chromatogr phy. ete. Tet there Is another aspeot of ths problem, vis., the type of motels which show readiness to undergo chelation or complex Ion formation. It is ween that most Of the investIgstlons on complexes have bean limited to the metels of transition series. Complexes of nontraawltion elements so far investig«ted are quite small in drawer and reactive of analytical import-nee (usually weawd on colour changes) have only ween etudled with dyes (substituted and unwubaUtutcd), pigments, s fsw amines and aalo-otsaplexea. As such there exists enough scops for investigatlag new ooaplexing and chelating agents which amy be specific for non-tranaitlon elements. To one such class of reagents belong the anils which though not well reoognlssd aw chelating agents, are known for exhibiting a resonating structure when brought in contact with different Lewis acids. Study with these compounds can, therefore, fora a new b^sls of study In the field of co-ordination onanistry. Before introducing the subject on the interaction Wf aetala with anile and its derlvatlvee, it will not he ut of place If a brief survey of the chealetry of -nils, Lswia acids and of ths different physic-chemical techniques employed to study complexes la a»ds. AHILS Anils arw organic compounds obtained by condensing 3 eroaetie aldwhydws with wiwaatlw a-sinee, Tawy arw represented by a foraula RR'C - H- RM . Where R way he em alkyl, aryl or hydrogen attached to wn imino carbon or aitrogwn. They are often referred as Sohifffo (2) bases after the none of the dieeoverer, Sehiff (18S4)V A aechPTiiwm rega ding their preparation apy be givea belowi > C « 0 ♦ HfWRw • <i •" • i in R» OH 1 - C «• I *» L > 0 • H - Rf* ♦ %0 Tha rwactio i is acid oatalyawd an* is generally carried out by refluxing the carboayl eosipouad an^ the anlne with aa aaeotroplc agent, like sine chloride, If accessary. Anile show HitIs or no tendency to polymeria? spontan eously but any be polymerised by heat and acids. For •sample, wwawjalealllawt O^Rr-CR » *%%, Is resinlfied on heating with aqueoue hydrochloric eeid or formic awid<3). Xoarea wnd Mignonaw*4* oyathesised various enils by the action of an aryl Orlgaard reagent with an aryl cyanide. Mont ague at el^8* leter found thafc certain 4 aailldsB, which aey be regarded as ^-hydroxy lmines, react with alkyl or aryl Orlgnarde to give the corres ponding lalaws in «*bout 40"/ yields. Hitter wae the first to dshydrogsnats amines to give lalaww' '. He found that isobomyl aniline ie readily dehydrogenoted with eulpher at $?19Q t give an yiwld of about 89 Jf of the anil of oertphor*