Fabrication of infinite two-dimensional sheets of tetragonal metal(II) lattices: X-ray crystal structures and magnetic properties of [M(CA)(pyz)]n (M2+=Mn2+ and Co2+; H2CA=chloranilic acid; pyz=pyrazine)

New cobalt(II) and manganese(II) co-ordination polymers containing tetragonal lattices [M(CA)(pyz)]n (M2+=Mn2+ (1) and Co2+ (2); H2CA=chloranilic acid; pyz=pyrazine) have been synthesized and characterized. Both compounds 1 and 2 are isomorphous. Each metal atom for 1 and 2 displays a six-coordinate geometry with the two bis-chelating CA2− anions and pyz molecules, providing an infinite square grid sheet. The temperature dependence of magnetic susceptibilities revealed the presence of antiferromagnetic interaction with J=−0.32 cm−1, zJ′=−0.34 cm−1, g=2.00 for 1 and J=−1.09 cm−1, J′=−0.55 cm−1, g=2.27 for 2, respectively.