Mixed salts of amino acids with different anions are of considerable interest from chemical and structural points of view and also as a source of new materials the properties of which can be controlled by appropriate choice of anions. Four such crystals, L-His(2+)center dot Cl-center dot HSO4- (P2(1)2(1)2(1), Z=4), L-Arg2(+)center dot NO3-center dot ClO4- (delta-form, P2(1), Z=4), L-Arg(2+)center dot F-center dot NO3- (P1, Z=2), 2L-Arg(2+)center dot(F-center dot center dot center dot HF)center dot 3NO(3)(-) (P2(1)2(1)2(1), Z=4), have been characterized structurally and by IR and Raman spectra. The hydrogen bond between the carboxyl group and the fluoride ion (2.371(3)angstrom) in the structure of L-Arg(2+)center dot F-center dot NO3- is among the shortest known O-H center dot center dot center dot F type hydrogen bonds. The O-H center dot center dot center dot F hydrogen bond in the structure of 2L-Arg(2+)center dot(F-center dot center dot center dot HF)center dot 3NO(3) is even shorter (2.341(2)angstrom) and thus belongs to the shortest contacts among both O-H center dot center dot center dot F and F-H center dot center dot center dot O types hydrogen bonds. (C) 2011 Elsevier B.V. All rights reserved.