Crystal structure of the nonlinear optical compound L-arginine fluoride

L-arginine fluoride is a promising compound that exhibits nonlinear optical properties. It efficiently converts two single photons of the same polariz ation and frequency ru to one photon of frequency 2 omega (type I phase mat ching). C6H15N4O2+F- is monoclinic, space group P2(1), a = 5.4475(4) Angstr om, b = 8.5133(6) Angstrom, c = 10.2195(7) Angstrom, beta = 93.475(6)degree s. The cation has a zwitterionic form, protonated at both the guanidyl and amino groups. The arginine C gamma atom is in a trans position to the carbo xyl group. A complex three-dimensional hydrogen bond network links the anio ns and cations together.