Hydrothermal Approach for Reticular Synthesis of Coordination Assemblies with Dicarboxylatotetramethyldistannoxanes as the Secondary Building Units

Hydrothermal reaction of trimethyltin chloride with 1,2,4,5-benzenetetracarboxylic acid (H4L1), 2,3-pyridinedicarboxylic acid (H2L2) or 1,4,5,8-naphthalenetetracarboxylic acid 4,5-anhydride (H2L3) under optimized pH (5-6) and temperature (130 degrees C) results in the isolation of new dicarboxylatotetramethyldistannoxane-based two-/three-dimensional coordination assemblies, [{Me2Sn(L-1)(0.25)}(2)O] (1, 2as supramolecular isomers), [{Me2Sn(L-2)(0.5)}(2)O] (3) and [{Me2Sn(L-3)(0.5)}(2)O] (4). The reaction in each case proceeds with selective cleavage of Sn-C bond. Analogous reaction of trimethyltin chloride with H(4)L(1)at 100 degrees C affords [Me3Sn(L-1)(0.25)] (5). The supramolecular coordination isomers1and2withcdsandlvtnetwork topologies, respectively are the first representatives among the distannoxane family; the latter confers large solvent accessible voids of 37 % per unit cell. The formation of ladder distannoxane, [{Me2Sn(O2C)}(2)O](2)as a common structural motif in1,3and4is a manifestation of a predefined geometry of the inorganic secondary building unit (SBU) and follows the benchmark of reticular chemistry approach. The coordination assembly,5adopts an eight-connected uninodal net that belongs tobcutopology. These are thermally stable up to 250-400 degrees C and retain their crystallinity even after exposure to hydrothermal treatment for 24 h.