Synthesis and study of hydrogen hexamolybdonickelate and hydrogen hexamolybdozincate with the cobaltammine cation

[Co(NH3)6] · H2[NiMo6O18(OH)6] · 6H2O (I) and [Co(NH3)6] · H2[ZnMo6O18(OH)6] · 6H2O (II) have been synthesized and studied by mass spectroscopy, thermogravimetry, and X-ray powder diffraction. The crystals of compounds I and II are monoclinic, Z = 1; for compound I: a = 16.10 A, b = 5.58 A, c = 12.22 A, β = 117.86°, V = 1045.14 A3, and ρcalcd = 2.26 g/cm3; for compound II: a = 16.12 A, b = 5.52 A, c = 12.12 A, β = 117.90°, V = 1043.21 A3, and ρcalcd = 2.21 g/cm3.