Crystal structure of polysulfonamides

Structures of poly(alkylene‐1,3‐benzenedisulfonamide)s [HN(CH2)mNHO2SC6H4SO2]n (PMm: 2 ≤ m ≤ 6) were studied by x‐ray diffraction and infrared spectroscopy. The crystal structure of PB6 is monoclinic, space group C2/mC2h3, with a = 7.70 Å, b = 7.76 Å, c (molecular axis) = 14.1 Å, and β = 117°. Two mirror‐image molecules repeating with two monomeric units in an identity period 28.2 Å occupy the same lattice site with equal probability. The alkylene chains assume the planar zigzag conformation, which is the structure isomorphous with PB4. An intermolecular hydrogen bond is formed between each NH group and one of the two O = S groups of the corresponding SO2 unit. The c axis tends to tilt from the fiber axis by an inclination angle of about 3° around the b axis.