Transition metal halide salts and complexes of 2-aminopyrimidine:: Cobalt(II) and nickel(II) compounds, crystal structures of bis(2-aminopyrimidinium)MX4 [M = Co, Ni; X = Cl, Br] and 2-aminopyrimidinium(+2) [NiBr2(H2O)4]Br2

The reaction Of MX2 (M = Co(II), Ni(II); X = Cl, Br) with 2-aminopyrimidine in aqueous acid yields compounds [(2-apmH)(2)MX4], (2-apmH)(2)[MX4], or (2-apmH(2)) [MX2(H2O)(4)]X-2 (2-apmH = 2-aminopyrimidinium; 2-apmH(2)=2-aminopyrimidinium(2+)). All compounds have been characterized by single crystal X-ray diffraction. The compounds [(2-apmH)2MX4] with M = Co, X = Cl (1); M = Ni, X = Cl (3); and M = Ni, X = Br (4) are isomorphous and crystallize as nearly square planar MX4 units with the 2-apmH cations coordinated in the axial sites through the unprotonated ring nitrogen. (2-ApmH)(2)[CoBr4] (2) crystallizes as the salt with a nearly tetrahedral CuBr42- anion. (2-ApmH(2)) [NiBr2(H2O)(4)]Br-2 (5) forms as a cocrystal of the neutral, six-coordinate nickel complex and (2-ampH(2))Br-2, stabilized by extensive hydrogen bonding. Crystal data (1): monoclinic, P2(1)/c, a=7.540(4), b=12.954(4), c=7.277(3)Angstrom, beta=110.09(6), V=667.4(5)Angstrom(3), Z=2, D-calc = 1.955 Mg/m(3), mu=2.079mm(-1), R=0.0501 for [\I\greater than or equal to2sigma(I)]. For (2): triclinic, P-1, a=7.720(2), b=7.916(2), c=14.797(3)Angstrom, alpha=97.264(3), beta=104.788(3), gamma=105.171(3)degrees, V=825.3(3)Angstrom(3), Z=2, D-calc = 2.296 Mg/m(3), mu = 10.715 mm(-1), R = 0.0308 for [\I\greater than or equal to2sigma(I)]. For (3): monoclinic, P2(1)/c, a = 7.595(3), b=12.891(4), c=7.204(3)Angstrom, beta=111.07(3)degrees, V=658.2Angstrom(3), Z=2, D-calc=1.982Mg/m(3), mu = 2.279 mm(-1), R=0.0552 for [\I\greater than or equal to2sigma(I)]. For (4): monoclinic, P2(1)/c, a=7.840(2), b=13.358(4), c=7.518(2)Angstrom, beta=110.923(3)degrees, V=938.6(3)Angstrom(3), Z = 2, D-calc = 2.577 Mg/m(3), mu = 12.18 mm(-1), R = 0.0280 for [\I\greater than or equal to2sigma(I)]. For (5): orthorhombic, Prima, a = 16.776(6), b = 11.943(4), c = 7.079(3)Angstrom, V = 1418.2(9)Angstrom(3), Z = 4, D-calc = 2.564 Mg/m(3), mu = 12.639 mm(-1), R = 0.0381 for [\I\greater than or equal to2sigma(I)].