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·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.