CRYSTAL STUDIES OF MUSK COMPOUNDS. XIV. A REDETERMINATION OF THE MOLECULAR STRUCTURES OF THREE NITROBENZENE MUSKS : DISCUSSION OF THE GEOMETRY OF A TERT‐BUTYL GROUP ATTACHED TO A BENZENE RING AND EMBEDDED BY TWO NITRO GROUPS

The crystal structures of Musk Xylene (1, 1-tert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene), Musk Ketone (2, 4-acetyl-1-tert-butyl-3,5-dimethyl-2,6-dinitrobenzene) and Musk Tibetene (3, 1-tert-butyl-3,4,5-trimethyl-2,6-dinitrobenzene) have been redetermined (1 and 3 at reduced temperature) and the accuracy is compared. Compound 2 has four molecules in the asymmetric unit but no additional crystallographic symmetry could be detected. The tert-butyl group in the molecules is adjacent to two nitro groups at the neighbouring sites and a systematic pattern is observed in its bond distances and angles. The influence of a tert-butyl group on the endocyclic angles of a phenyl ring is discussed.