Polyiodides of L-ornithine. Discovery of a symmetric (L-Orn(H)-H-L-OrnH) (3+)-cation

Abstract

Two polyiodides of l-ornithine, (l-OrnH₂)(I₃)(I)(I₂) (I) and (l-Orn(H)-H-l-OrnH)(I₃)₃·4H₂O (II) have been synthesized and characterized structurally, by IR, Raman and UV-Vis spectroscopy. Electronic structures of both were determined by quantum chemical calculation based on their structures and bandgaps were measured experimentally as well. Salt (I) is triclinic, space group P1 with two formula units in the unit cell, salt (II) crystallizes in the monoclinic space group C2 with half of formula unit in the asymmetric unit. A symmetric dimeric cation (l-Orn(H)-H-l-OrnH) was observed in the structure of (II) for the first time.