Figure 1
Representation of the hydrogen-bonded heterosynthons formed between 2,2′-biimidazole molecules (free and coordinated) with the different complementary moieties (carboxylic acid, carboxylate and halogen). An isographic
R22(9) graph set can be designated for Ia, Ib, Ic and Id, while an
R21(7) graph set is assigned for Ie and If (Etter et al., 1990). |