Indian Journal of Chemistry Vo\.38A, October 1999, pp. 1060-1062 Synthesis and characterization of benzilmonoxime complexes of organo si licon(IV) M S Singh* , M D Raju & A K Singh School of Stud ie s in Chemistry, Vi kram University, UJjai n 45 6 0 10 (MP) , Indi a Received 14 May 1998; revised 3 March 1999 Complexes of the general formul a Me3S nL, Me2 SnLn C1 2 - 0 and MeSnL n C1 3 . n ( wher e LH=benzilmonox ime) have been prepared by reacting organosilicon{IV) chlorides with the sodium sa lt of the ligand (prepared ill situ) in d iffe rent molar ratios. These complexes have bee n characterised by elemental a na lyses, molecular we ig ht determinations. conductivity measurements and spectral (IR, IH and DC NMR) studies. The pec uliar beha viour of silicon(IV) and the vital role its complexes play in chemic al and biological proce sses are of im me nse importance and are thought provoking in the realm of coo rdination chemistryl. During the past few years, a pl et hora of referen ces describing the organosilicon comp lexes of N, 0 and N, S donor Schiff bases have appea red in the literature 2 - s . Certa in organos il icon compounds kave bee n extensively used in chemical vapour deposition 6 and m deoxygenation reactions m org anic transformations 7 . Ho weve r, little is known about the complexing beh aviou r of sili con with oxime. Oximes are impo rtant from bioch em ic al point of view 8 ". A recent rev iew deals with complexes of oximes and oximato species, which are bidentate ligands capable of coordinating via oxygen and nitrogen 8b . Our continuing interest in the synthesis of biologically active complexes and in continuation to our recent report 9n organo silicon(I V)9 -11, have led us to synthesise and study the structura l as we ll as other features of organosilicon (1V) complexes of benzilmonoxime. Exper imenta l C hem icals and solvents used were dried and d 15 d . purified by standard met ho s an mOisture was excluded throu gh out the exper imental manipu lation s. All the melting points are uncorrected. Meth yl si li con chlorides i.e. MC3S iCI, Me z SiCI 2 and MeSiCh , were procured from E Merek or Aldrich and were used as such. Benzilmo'1oximc was prepa red according to the literature method l2 an d reerystallis ed before use. IR spectTa were recorded on a Perkin-El mer mo del 377 in the range of 4000-200 em-I. IH and 13C l\TMR spectra were obtained at 200 a nd 50 MHz, r espe ctively (Brucker AC 200), in CDCh as solven t. Chemical shifts were recor de d in ppm (0) relative to TMS as an intemal standard. Microanalyses were performed by Cole man Carbon, Hydrogen and Nitrogen analysers for C,H and N respectively. Silicon and chlorine were estimated gravimetrically as Si0 2 and AgCl respectively, described elsewhere l2 and are in good agree ment with the calcul ated values (Table I). Th e details concerning the molar conductan;e m easuremen ts are similar to those reported previously 13 . Molecular weights were me asured on Knauer Vapour Pre ssure Osmometer in dilute (20g li tre-I ) CHCl 3 so lution at room tempe rature. Reaction between Me3SiCI and the sodium sa lt of ben- zilmonoxime in I: I molar ratio To a weighed amo unt of trimethylsilico n chloride (0.71 g, 6.54 mmol) in 20 ml of d ry iso propanol wa s added a calculated amount of sodium salt of the ligand, prepared by treating the ligand (I.47 g, 6.54 ?H ,N .,N..?f -c benzene Ph .... C Me, Si CI + I +Na I Ph i-PrOH P h---C .. o -NaCl 0 Compd.t ?fJ M S·C' + Ph _C ... N +·n Na ben.zeq,e e, . ., n I i-PrOH Ph- C ... O =nNaCI (Where, n= I, Cempd.2; 0=2, Compd.3) ?H] r ?1 SlMeCt,.., .. n Ph_ C,N ... 0 Na I l-PrOH Ph--C", Ph -C .. O nNaCI 0 n (Where n= I ,Compd; 4; n=2, Compd.5;.n=3 Compd_6) Scheme I