Salts of 2-amino-5-iodopyridinium

Abstract

Reaction of 2-amino-5-iodopyridine (5IAP) with concentrated HBr at room temperature yielded 2-amino-5-iodopyridinium bromide, C5H6IN2+·Br− or (5IAPH)Br. The complex formed pale-yellow crystals, which exhibit significant hydrogen bonding between the amino and pyridinium N—H donors and bromide ion acceptors. Halogen bonding is also observed. Similarly, reaction of 5IAP with cobalt(II) chloride in mixed HCl/HBr in 1-propanol yielded 2-amino-5-iodopyridinium (2-amino-5-iodopyridine-κN1)bromido/chlorido(0.51/2.48)cobalt(II), (C5H6IN2)[CoBr0.51Cl2.48(C5H5IN2)] or (5-IAPH)[(5IAP)CoCl2.48Br0.51], as blue block-shaped crystals. Two of the three halide positions exhibit mixed occupancy [Cl/Br = 0.797 (5):0.203 (5) and 0.689 (6):0.311 (6)], while the third position is occupied solely by a chloride ion. Extensive hydrogen and halogen bonding is observed.

Keywords

• crystal structure
• 2-amino-5-iodopyridine
• co(ii)