Available online www.jocpr.com Journal of Chemical and Pharmaceutical Research, 2015, 7(4):356-365 Research Article ISSN : 0975-7384 CODEN(USA) : JCPRC5 356 Ditolyldithiophosphates of titanium: Synthesis, characterization and in vitro antimicrobial and cytotoxic studies Atiya Syed, Ruchi Khajuria, Sandeep Kumar and Sushil K. Pandey * Department of Chemistry, University of Jammu, Baba Saheb Ambedkar Road, Jammu(J & K), India _____________________________________________________________________________________________ ABSTRACT Ditolyldithiophosphates of titanium corresponding to [(C 5 H 5 ) 2 Ti{S 2 P(OAr) 2 } n Cl 2-n ] (Ar = o-, m-, p-CH 3 C 6 H 4 , p-Cl- m-CH 3 C 6 H 3 ; n = 1 and 2) have been synthesized and characterized by elemental analyses, IR, mass and heteronuclear NMR ( 1 H, 13 C and 31 P) spectroscopic analyses. The combined DTA/DTG thermal analysis of [{(p- CH 3 C 6 H 4 O) 2 PS 2 } 2 Ti(C 5 H 5 ) 2 ] has yielded final thermolysis product as TiS 2 . Cyclic voltammetry probed the redox capabilities of [{(m-CH 3 C 6 H 4 O) 2 PS 2 } 2 Ti(C 5 H 5 ) 2 ]. Comparison of antimicrobial activity of the ligands and complexes has shown that the complexes are more effective than the ligands. The in vitro cytotoxic investigations against the cultivated human cell lines revealed that the titanium complexes are more active. Keywords: Ditolyldithiophosphates, Titanium, Thermogravimetric analysis, Antimicrobial, Cytotoxicity. _____________________________________________________________________________________________ INTRODUCTION In recent decades the field of drug designing has seen a surge toward pharmaceuticals that are inorganic in nature [1]. A variety of increasingly effective titanocene derivatives have been developed for use as chemotherapeutic agents since titanocene dichloride was discovered to possess antitumor characteristics [2]. In fact, titanocene is the first non-platinum coordination complex to undergo clinical trials [3]. The transition metal complexes with sulfur based donors are of significant interest as synthetic analogs for the active sites of metalloproteins since these are known to possess affinity toward sulfur ligands [4]. The interest in this research area has grown considerably in the recent years [5]. The biological aspect of dithiophosphates has been well established in the rapidly growing field of phosphorus- sulfur chemistry [6-9]. The dithiophosphates have received much attention for their extensive applications as biocides [10] analytical reagents [11], antiwear and antioxidant additives in motor oils [12]. Cyclic voltammetry has been used to study the electrochemistry of the new compounds. The examination of electrochemistry of bis(cyclopentadienyl)titanium dichloride has demonstrated a single electron redox process [13]. Further, the dependence of standard potential on steric behavior of cyclopentadienyl rings has also been observed [14]. Recently, the complexes of alkylenedithiophosphates with titanocene and zirconocene have been reported [15-17]. However, no attention has yet been given to ditolyldithiophosphate complexes of titanocene. Considering the promising antitumor properties of titanocene dichloride it seemed reasonable to investigate the titanium complexes with ditolyldithiophosphates using titanocene. Moreover, considering the extensive biological features of titanocene and the ligand, the antimicrobial as well as cytotoxic screening studies have been reported herein. EXPERIMENTAL SECTION Titanocene dichloride (Himedia) was used as supplied. Solvents (toluene and dichloromethane) were distilled and dried before use. The sodium salts of O,O’-(o-, m-, p-, p-Cl-m-ditolyl)dithiophosphates were synthesized according