Synthetic, spectral, thermal and antimicrobial studies on some mixed 1,3-dithia-2-stannacyclopentane derivatives with dialkyldithiocarbamates H.P.S. Chauhan * , Nagulu Meera Shaik School of Chemical Sciences, Devi Ahilya University, Takshashila Campus, Khandwa Road, Indore 452 017, India Received 21 July 2004; received in revised form 20 October 2004; accepted 25 October 2004 Available online 8 December 2004 Abstract 1,3-Dithia-2-stannacyclopentane derivatives with dialkyldithiocarbamates of the types (I) and (II) (where R = CH 3 ,C 2 H 5 and –CH 2 –CH 2 –) have been synthesized by the reaction of 2,2-dichloro-1,3- dithia-2-stannacyclopentane and sodium/ammonium salts of dialkyldithiocarbamates in 1:1 and 1:2 molar ratios, respectively, in anhydrous benzene. These newly synthesized derivatives have been characterized by elemental analyses (C, H, N, S and Sn), thermal [thermogravimetry (TG) and differential thermal analyses (DTA)] as well as spectral [UV, IR and multinuclear NMR ( 1 H, 13 C and 119 Sn)] studies. The monodentate behaviour of the dialkyldithiocarabamate ligands was confirmed by IR and 119 Sn NMR spectral data and distorted tetrahedral structures have been suggested for both type (I) and (II) compounds. The free ligands and their tin complexes have also been screened for their antibacterial and antifungal activities. These results made it desirable to delineate a com- parison between free ligands and their tin complexes. These exhibit higher antibacterial effect than some of the previously investi- gated antibiotics. Ó 2004 Elsevier B.V. All rights reserved. Keywords: Tin(IV); 1,2-Dithiolates; Dialkyldithiocarbamates; Thermal studies; NMR; Antimicrobial activity 1. Introduction Complexing agents with a dithio functional group [1] have been widely used in industry as rodent repellents, vulcanization additives in rubber manufacturing, addi- tives in lubricants and in agriculture as fungicides on al- mond trees, stone fruits and vegetables. Interest in main group metal complexes with dithiocarbamate ligands arises in part because of their varied structural possibil- ities (Fig. 1) and biological activities [2,3]. Present interest in the study of dialkyldithiocarba- mate compounds has been renewed with the utilization of dithiocarbamate as coadjuvant in acquired immune deficiency syndrome (AIDS) treatment [4]. Thermo ana- lytical data are important when related to the industrial application of such compounds [5]. Most of the publications are restricted only on synthe- sis and characterization of tin(IV) and organotin(IV) derivatives with sulphur ligands like dithiolates [6,7] and dialkyldithiocarbamates [8–19]. A large number of diorganotin(IV) dialkyldithiocarbamate derivatives have been known including X-ray crystal structures of [Ph(Bu)Sn(S 2 CNEt 2 )Cl] [11], [R 2 Sn(S 2 CNMe 2 ) 2 ] [12], {(Me) 2 Sn[S 2 CN(CH 2 ) 5 ] 2 } [13], {(Me) 2 Sn[S 2 CN(CH 2 ) 4 ] 2 } [14], [R 2 Sn(S 2 CNEt 2 ) 2 ] [16] [(Me) 2 Sn(S 2 CNEt 2 ) 2 ] [18], 0162-0134/$ - see front matter Ó 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.jinorgbio.2004.10.031 * Corresponding author. Tel.: +91 731 2460208; fax: +91 731 2365782. E-mail address: hpsc@rediffmail.com (H.P.S. Chauhan). www.elsevier.com/locate/jinorgbio Journal of Inorganic Biochemistry 99 (2005) 538–545 JOURNAL OF Inorganic Biochemistry