Diamondoid and Square Grid Networks in the Same Structure. Crystal Engineering with the Iodo···Nitro Supramolecular Synthon

Abstract

In principle, an organic diamondoid structure could follow from any of four possibilities: a single molecule of the type AX4 assembles via X···X interactions; two molecules, e.g. AX4 and BY4, assemble via X···Y interactions; either of the first two possibilities is modified with appropriate linear spacer molecules; a single molecule AX2Y2 assembles via X···Y interactions. This communication deals with the last possibility, wherein the X···Y link is based on the polarization-assisted 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 Td nodes of 1 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.