Diamondoid and square grid networks in the same structure.: Crystal engineering with the iodo•••nitro supramolecular synthon

In principle, an organic diamondoid structure could follow from any of four possibilities: a single molecule of the type AX(4) assembles via X...X interactions; two molecules, e.g. AX(4) and BY4, assemble via X...Y interactions; either of the first two possibilities is modified with appropriate linear spacer molecules; a single molecule AX(2)Y(2) assembles via X...Y interactions. This communication deals with the last possibility, wherein the X...Y link is based on the polarizationassisted I...O2N synthon. A notable feature of the crystal structure of 4,4'-diiodo-4",4"-dinitrotetraphenylmethane (1) is the existence of a divergent mode of iodo-nitro association. The T-d nodes of I are interconnected with the I atom bifurcated by O atoms from two NO2 groups such that each molecule of 1 is connected to eight others through I...O contacts. The result is a combination of 5-fold diamondoid and 3-fold square grid networks. All I...O interactions observed are short and strong, and there is a pronounced tendency to achieve close packing with the two coexisting networks.