As a part of this diploma thesis, methylammonium halometalates(II) of the general formula (MA)2[MX4], (M2+ = Cu2+ , Mn2+ , X‒ = Cl‒ , Br‒ ) and mixed derivates (MA)2[MClxBr(4-x)] (M2+ = Cu2+ , Mn2+ ), (MA)2[CuxMn(1-x)Cl4] i (MA)2[CuxMn(1-x)Br4] were prepared. Methylammonium tetrachlorocuprates(II), tetrachloromanganates(II) and tetrabromocuprates(II) were prepared by solution synthesis starting from methylamine and halide salts of copper(II) and manganese(II), with the addition of HCl or HBr. A series of mixed methylammonium (with the highest mass fraction of Br‒ of 0.6) was prepared by the reaction of CuO and methylamine with different ratios of HCl and HBr. (MA)2[CuBr4] and (MA)2[MnBr4] were prepared by mechanochemical synthesis from CH3NH3Br and CuBr2 respectively MnBr2. (MA)2[CuCl4] and (MA)2[MnCl4] were prepared from CH3NH3Cl and CuCl2 (CuCl2·2H2O) and MnCl2 (MnCl2·4H2O). Mixed methylammonium halocuprates(II) and halomanganates(II) as well as a series of mixed methylammonium tetrachlorometalates(II) and tetrabromometalates(II) were prepared by mechanochemical synthesis. The identification of the prepared compounds was carried out with infrared (IR) spectroscopy, X-ray diffraction on a single crystal and powder samples. The mass fractions of Mn and Cu were determined by mass spectrometry with inductively coupled plasma ICP-MS, while the fractions of total halides were determined by Fajans method of precipitation titration.