Structure–reactivity correlation of photochemical reactions in organic crystals: intramolecular hydrogen abstraction in an aromatic nitro compound
The molecular structure of 1,4-bis-(2-chloro-1,1-dimethylethyl)-2-nitrobenzene has been determined by X-ray crystallography. The single-crystal X-ray investigation, R= 0.067, showed the compound to be monoclinic, space group P21, a= 6.388(2), b= 13.848(4), c= 8.578(3)Å, β= 94.05(3)°. Structural analysis of 2-nitro-t-butylbenzenes which undergo intramolecular hydrogen abstraction in the solid state upon irradiation by u.v. light was carried out in connection with structure–reactivity correlation studies and X-ray crystallographic investigations. On the basis of intramolecular geometry and molecular packing considerations, it has been possible to identify the hydrogen atom abstracted preferentially in crystals of this compound. The benzene ring is found to exist in the boat conformation.