Main Group Metal Chemistry Vol. 25, No. 1, 2002 ORGANOTIN DITHIOCARBAMATES DERIVED FROM HYDROXYLATED AMINES Yang Farina*, 1 Abdul Hamid Othman, 1 Ibrahim Baba, 1 Seik Weng Ng, 2 and Hoong-Kun Fun 3 'School of Chemical Sciences & Food Technology, Faculty of Science & Technology, Universiti Kebangsaan Malaysia, 436(X) Bangi, Malaysia ^Institute of Postgraduate Studies, Universiti Malaya, 50603 Kuala Lumpur, Malaysia 'X-ray Crystallography Unit, Universiti Sains Malaysia, 11800 Penang, Malaysia Abstract The organotin(IV) dithiocarbamates derived from hydroxylated amines were synthesised. Two general synthesis routes were utilised in the attempts to prepare these organotin(IV) dithiocarbamates, namely the metathesis and the insertion methods. The insertion method of preparation was found to be more suitable. In the insertion method carbon disulphide was added drop wise to an ethanolic mixture of the secondary amine (diethanolamine and methylethanolamine) and the respective organotin(IV) compounds (dimethyltin(IV), dibutyltin(IV) and diphenyltin(IV) chloride). The reaction temperature was controlled to remain at 0°C to avoid possible decomposition. Isolated complexes were analysed using infrared, ultraviolet, 'H and 13 C NMR spectroscopic methods. Quantitative analyses were carried out using CHN and tin analysis. The crystal structures of some of the compounds that were prepared showed that the mode of chelation between the organotin moiety and the ligand depended on steric requirements. Presence of the hydroxyl groups resulted in intermolecular and intramolecular hydrogen bonding. Introduction Dithiocarbamate compounds have been found to be biologically active because some dithiocarbamates such as imuthiol (sodium diethydithiocarbamate) has been utilised in the pharmaceutical industry. Lupus, an "auto-immune" disease has been successfully treated with imuthiol 1 . Dithiocarbamates are widely used in the polymer industry as accelerators and antioxidants. Organotin compounds are known to be biologically active as they are widely used as wood preservatives and fungicides, marine antifouling agents, agrochemical fungicides and miticides, and in disinfectants. Research in the anti-tumour activity of organotin compounds started in the 70's. The potential of such compounds as anti-tumour agents have been studied by several workers 2 " 5 . Since 1980, United States National Cancer Institute has tested over 1000 tin compounds and 170 of these were found to be active. An extensive list of organotin compounds which were tested against P388 Lympocyte Leukemia showed great promise as possible anti-tumour agents. Other areas of human medicine where tin compounds are showing potential include the treatment of the parasitic diseases, their use as anti-inflammatory and antivirial agents. The diorganotins are the largest group of tin compounds studied for antitumour activity. Organotins chelated to oxygen donating ligands have been found to be active towards a number of tumour cells. The results of the testings showed that these oxygen containing organotins were even more effective than cis-platin 5 . The dithiocarbamate complexes with various metals arc used in the pharmaceutical industry. It is thus anticipated that organostanum dithiocarbamate would show biological activity. In order to cam' out biological tests on new dithiocarbamates the complexes will have to be synthesised and chemically characterised first. There are basically two methods employed in the synthesis of these complexes namely the metathesis and insertion methods 67 . In the metathesis method the ammonium salt of diethanoldithiocarbamate is reacted with the respective organotin(IV) chloride compounds. In the insertion method the ligand is formed in situ and is reacted directly with the various organotin(IV) chlorides. The preparation and characterisation of dimethyltin(IV), dibutyltin(IV) and diphenyltin(IV) with diethanoldithiocarbamates and methylethanoldithiocarbamates are described in this paper. Materials and Methods The compounds dimethyltin(IV) and dibutyltin(IV) chloride were obtained from Merck while diphenyltin(IV) chloride were purchased from Aldrich Chemicals. The bases diethanolamine and methylethanol were supplied by Merck and BDH respectively while carbon disulphide was purchased from Unilab. All the chemicals were used without further purification. Metathesis method: The ammonium salt of the diethanoldithiocarbamate and the methylethanoldithiocarbamate anions were prepared by the drop wise addition of a carbon disulphide solution (60 mL, 0.1 mol of CS 2 in 60 mL ethanol) to a rapidly stirred 0°C mixture of the respective amine 67