Iodides and polyiodides of L-arginine

Exploring l-arginine salts, particularly halogenides, for their nonlinear optical properties has been a subject of significant interest. While various l-arginine salts were extensively studied, their iodide counterparts remained elusive until recent investigations. This study aims to synthesize and characterize l-argininium(+) iodide (l-ArgH)(I) (I), to reinvestigate l-argininium(2+) bis-iodide (l-ArgH(2))(I)(2) (II), and explore l-argininium(2+) bis-triiodide (l-ArgH(2))(I-3)(2) (III), l-argininium(+) triiodide (l-ArgH)(I-3) (IV) and bis-l-argininium(+) triiodide pentaiodide (l-ArgH)(2)(I-3)(I-5) (V). Crystal structures of salts (I-III) were determined to elucidate their molecular arrangements. Infrared and Raman spectra of all five compounds were registered and discussed. Electronic band structures of the salts (I-III) were determined by quantum chemical calculations.