Water driven formation of channels: unusual solid-state structural transformation of a heterometallic polymer

The backbone hetero-organometallic polymer trans-{[RuCp(PTA)(2)-mu-CN-RuCp(PTA)(2)-mu-CoCl3]}(n)center dot(DMSO)(n) (1 center dot DMSO) has been synthesized and transformed into cis-{[{RuCp(PTA)(2)-mu-CN-1 kappa C:2 kappa N-2-RuCp(PTA)(2)}-mu-CoCl3]}(n)center dot{[RuCp(PTA)(2)-mu-CN-1 kappa C:2 kappa N-2-RuCp(PTA)(2)]Cl}(0.5n)center dot(15H(2)O)(n) (2 center dot 15H(2)O) by addition of water to crystallization media (PTA = 1,3,5-triaza-7-phosphaadamantane). The new polymer 2 center dot 15H(2)O presents a nano-channeled molecular packing with pores filled by water molecules. The crystal structures of 1 center dot DMSO and 2 center dot 15H(2)O and the transformation process are herein presented and discussed.