Novel organotin(IV) complexes of organophosphorus ligands: Synthesis, spectroscopic, structural study and DFT calculations Zahra Shariatinia a, * , Ebadullah Asadi a , Mohammad Yousefi b , Marzieh Sohrabi b a Department of Chemistry, Amirkabir University of Technology (Polytechnic), P. O. Box 159163-4311, Tehran, Iran b Department of Chemistry, Shahre-Rey Branch, Islamic Azad University, Tehran, Iran article info Article history: Received 15 March 2012 Received in revised form 18 May 2012 Accepted 24 May 2012 Keywords: Phosphoric triamide Hydrogen bond NMR X-ray crystallography DFT calculation abstract Three new phosphoric triamides with general formula C 6 H 5 C(O)NHP(O)X 2 , where X ¼ N-4- phenylpiperazinyl (1), N-4-ethoxycarbonyl piperazinyl (2), and N-4-ethoxycarbonyl piperidinyl (3) as well as seven novel organotin(IV) complexes with formula SnClR 1 R 2 R 3 L 2 where R ¼ alkyl/aryl/Cl and L ¼ organophosphorus ligand, were synthesized and characterized by 1 H, 13 C, 31 P NMR, IR spectroscopy and elemental analysis. The 31 P{ 1 H} NMR spectra of compounds 9 and 10 each reveal two close signals that are related to their cis and trans isomers. DFT calculations were performed at B3LYP and M06 methods with LanL2DZ basis set using Gaussian 09 software on the cis and trans configurations of compounds 9 and 10. The structure of compound 1 was determined by X-ray crystallography. In this structure, there are two symmetrically independent molecules (1 and 1A) produced due to the co- crystallization of water and CH 3 OH molecules. The P]O and C]O bonds in both molecules 1 and 1A indicate an anti conformation relative to each other. The strong intermolecular NeH/O]P hydrogen bonds plus weak intermolecular CeH/O(1W), CeH/O]C, CeH/O]P and CeH/N hydrogen bonds create a three-dimensional polymeric chain in the crystalline network. Ó 2012 Elsevier B.V. All rights reserved. 1. Introduction Nowadays, phosphoric triamides have received considerable attention due to their unique properties like anti-HIV [1], anti-HCV [2,3], antibacterial [4] and anticancer drugs [5,6]. Besides, they indicate other useful applications in coordination chemistry [7,8]. The structural studies have been performed to correlate their properties to the structural factors [9,10]. The organotin(IV) coor- dination compounds are of interest in recent researches [11,12] that is specially due to their antitumor [13], agrochemical fungicidal and biocidal [14,15] properties. Current researches have indicated promising in vitro antitumor properties of organotin compounds against a wide range of human tumor cell lines [16,17]. In some cases, organotin(IV) derivatives have shown satisfactory anti- proliferative in vivo activity as new chemotherapy agents [18]. Recently, much attention has also been focused on their use as metal-based drugs [19]. Tin derivatives were used as homogeneous catalysts in esterification and transesterification reactions [20]. The synthesis and characterization of hexacoordinate cis and trans complexes of SnCl 4 with phosphoramide ligands have been repor- ted [21]. In this work, three new phosphoric triamides as well as seven novel organotin(IV) complexes with formula SnClR 1 R 2 R 3 L 2 where R ¼ alkyl/aryl/Cl and L ¼ organophosphorus ligand were synthe- sized and characterized by 1 H, 13 C, 31 P NMR, IR spectroscopy and elemental analysis. Also, the structure of compound 1 determined by X-ray crystallography indicated two symmetrically independent molecules (1 and 1A) in the crystalline lattice. The structures of cis and trans isomers of complexes 9 and 10 were optimized at B3LYP and M06 methods with LanL2DZ basis set using Gaussian 09 soft- ware. The spectroscopic results as well as structural factors were compared with each other and with the previously reported data. 2. Experimental 2.1. Spectroscopic measurements The 1 H, 13 C, 31 P and 119 Sn spectra were recorded on a Bruker Avance DRS 500 spectrometer. 1 H and 13 C chemical shifts were determined relative to internal Si(CH 3 ) 4 , 31 P and 119 Sn chemical shifts relative to 85% H 3 PO 4 and Sn(CH 3 ) 4 as external standards, respectively. Infrared (IR) spectra were recorded on a Shimadzu model IR-60 spectrometer. Elemental analysis was performed using a Heraeus CHN-O-RAPID apparatus. Melting points were obtained with an Electrothermal instrument. * Corresponding author. Tel.: þ98 2164542766; fax: þ98 2164542762. E-mail address: shariati@aut.ac.ir (Z. Shariatinia). Contents lists available at SciVerse ScienceDirect Journal of Organometallic Chemistry journal homepage: www.elsevier.com/locate/jorganchem 0022-328X/$ e see front matter Ó 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jorganchem.2012.05.025 Journal of Organometallic Chemistry 715 (2012) 82e92