Synthesis and characterization of diethyltin-based three dimensional self-assemblies derived from sulfonate-phosphonate ligands

Diethyltin(methoxy)methanesulfonate reacts readily with equimolar amount of t-butylphosphonic acid (RT, 8-10 h) in moist dichloromethane and methanol to afford (Et₂Sn)₆(O₃PBu^t)₄(OSO₂Me)₄·CH₂Cl₂]_n (1) and (Et₂Sn)₆(O₃PBu^t)₄(OSO₂Me)₄·2H₂O]_n (2), respectively. The identity of these compounds has been established by IR, multinuclear (¹H, ¹³C, ³¹P and ¹¹⁹Sn) NMR as well as X-ray crystallographic studies. Despite apparent similarity in the composition, a marked difference in the structural motifs between 1 and 2 is evident in the solid state. For 1, the formation of three-dimensional self- assembly results from μ₃-phosphonate and μ₂, μ₃-sulfonate binding modes and exhibits continuous channel of voids which are occupied by disordered CH₂Cl₂ molecules. In contrast, the sulfonate ligands in 2 act exclusively in μ₂-fashion and hydrogen bonding interactions (O-H?O) between coordinated water molecules and methanesulfonate groups is significant in the construction of 3D supramolecular assembly.