Cyclopentyldiphenyl(4-thiosemicarbazonopentanoato-κO)tin(IV)

The Sn atom in the title compound, [Sn(C5H9)(C6H5)2(C6H10N3O2S)], exists within a tetrahedral geometry. The –NH2 group forms a weak hydrogen bond across a center of inversion to the S atom of an adjacent molecule, as well as another weaker hydrogen (across another center of inversion) to the Sn-bound O atom of another molecule. The hydrogen-bonded layer structure is consolidated by a strong hydrogen bond between the –NH– group and the uncoordinated O atom of a third molecule.

The Sn atom in the title compound, [Sn(C 5 H 9 )(C 6 H 5 ) 2 -(C 6 H 10 N 3 O 2 S)], exists within a tetrahedral geometry. The -NH 2 group forms a weak hydrogen bond across a center of inversion to the S atom of an adjacent molecule, as well as another weaker hydrogen (across another center of inversion) to the Sn-bound O atom of another molecule. The hydrogenbonded layer structure is consolidated by a strong hydrogen bond between the -NH-group and the uncoordinated O atom of a third molecule.

S1. Comment
Triorganotin carboxylates having two different organyl substituents possess ehanced anti-bacterial and anti-fungal properties compared with the symmetrical compounds (Koshy et al., 2001). The synthesis of cyclopentyldiphenyltin hydroxide, which is the principal reagent that condenses readily with carboxylic acids, is a multi-step synthesis. Previous studies have characterized a few cyclopentyldiphenyltin derivatives (Lo & Ng, 2004;Lo et al., 1999;Teo et al., 2004). In the reaction with levulinic acid thiosemicarbazone (Ng, 1992), the organotin hydroxide yields a four-coordinate compound (I) ( Fig. 1 & Table 1). The tin atom exists in a tetrahedral geometry; adjacent molecules are linked by hydrogen bonds into a layer structure, Table 2.
Cyclopentyldiphenyltin hydroxide was sythesized by using a multistep reaction, starting from the Grignard reaction of cyclopentylmagnesium bromide on triphenyltin chloride. One phenyl radical was then cleaved by iodine in DMF; the resulting iodide was then hydrolyzed with sodium hydroxide in acetone to give the mixed triorganotin hydroxide (Lo et al., 1999). The thiosemicarbazone (1.1 g, 5 mmol) and triorganotin hydroxide (2 g, 5 mmol) were dissolved in hot ethanol (50 ml). The clear solution was filtered and colorless crystals separated from the cool solution after a day (yield: 75%).

S3. Refinement
Carbon-bound H-atoms were placed in calculated positions (C-H 0.95 to 0.99 Å) and were included in the refinement in the riding model approximation, with U(H) set to 1.2 to 1.5U(C). The nitrogen-bound H-atom were similarly generated (N-H 0.88±0.01 Å) and their temperature factors similarly tied.
The final difference Fourier map had a large peak at 1.4 Å from C1 but was otherwise diffuse.  70% Probability thermal ellipsoid plot of Sn(C 5 H 9 )(C 6 H 5 ) 2 (C 12 H 15 N 3 O 2 S), (I), show atom-numbering scheme. Hydrogen atoms are drawn as spheres of arbitrary radius.