Layered compounds incorporating 9,9'-spirobifluorene: hydrogen-bonded and metal-organic networks derived from 9,9'-spirobifluorene-2,2',7,7'-tetracarboxylic acid

A new tetracarboxylic acid derivative of 9,9'-spirobifluorene (9,9'-spirobifluorene-2,2',7,7'-tetracarboxylic acid (SBFTCA) ( 3)) has been prepared and crystallized as a THF solvate (3 center dot THF). Hydrogen bonding between adjacent molecules of 3 results in a ( 4,4) layer topology and non-interpenetrating AB layer stacking. The topology of 3 gives rise to pores that are occupied by disordered THF molecules. Under hydrothermal conditions, a mixture of 3, methylimidazole, and Co(NO3)(2) gives single crystals of a layered network ( 4) comprising the tetracarboxylate of 3 linked by Co(II) ions. The structure of 4 is similar to that of 3, THF exhibiting an AB motif, with two methylimidazole ligands per cobalt atom occupying the remaining volume.