Amino acids playing an important role in biological processes form complexes with many metals. Four complexes, namely, 2 SbF 3 ( + NH 3 CH 2 COO -) ( III ), SbF 3 ( + NH 3 CH 2 COO -) ( IV ), SbFO ( + NH 3 CH 2 COO -) ( V ) , and (NH 3 CH 2 COOH ) SbF 4 ( VI ) were synthesized in aqueous solutions via reaction of SbF 3 with the simplest amino acid, i.e., glycine + NH 3 CH 2 COO -( Gly ) [1]. Crystal structures of complexes IV and VI were also determined in [1].To continue our studies on synthesis of new Sb(III) fluoride complexes with amino acids, we investigated interaction of SbF 3 with aliphatic amino acids in an aqueous solution. The publication concerns the composition and structure of complexes formed in reaction of SbF 3 with α -aminoisovaleric acid (DL-valine, Val) in an aqueous solution.Synthesis. The starting reagents used in synthesis were Sb(III) fluoride (reagent grade), DL-valine (pure grade), and hydrofluoric acid. DL-valine (hereinafter valine), containing insignificant amount of impurity, was preliminarily purified before recrystallization from an aqueous solution. Synthesis of SbF 3 complexes with valine was performed by preparative method via reaction of SbF 3 with valine in an aqueous solution at the molar ratio of components (0.25-2) : 1 in the presence of hydrofluoric acid. The samples of reagents taken in a definite molar ratio were dissolved in water, the solutions were heated to 50-60°ë and poured together. The required pH of the solution (1-3) was monitored by the addition of HF acid. The reaction mixture was evaporated to 1/3 of its initial volume and allowed to stand for crystallization at room temperature. The obtained crystals were filtered in vacuum, washed with acetone on a funnel, and dried in air to a constant weight. The complexes thus formed were identified using chemical X-ray diffraction, and IR analyses. X-ray diffraction analysis of a faceted single crystal of complex I was performed on a SMART-1000 CCD Bruker diffractometer. The experimental data were collected at room temperature in sets of 906, 580, and 360 frames at ϕ = 0°, 90° , and 180° , respectively, using ω scan mode at a step of 0.3° and with 30 s per frame. The absorption was corrected by the crystal faces.The structure was solved by the direct methods and refined by the least-squares method in a full-matrix anisotropic approximation for all non-hydrogen atoms. Hydrogen atoms were located geometrically and refined in isotropic variant with fixed thermal parameters ( U H = 0.0 65 Å) for a limited set of reflections at the initial stage (sin θ / λ = 0.55) and for all reflections at the final stage.The data collection, processing, and refinement of unit cell parameters were carried out with the SMART and SAINT-Plus programs [2]. All calculations for determination and refinement of the structure were performed with the SHELXTL/PC program packages [3].Selected crystallographic data and results of refinement of the structure are given in Table 1, the atomic coordinates and their thermal parameters are presented in Tabl...