Synthesis, crystal structure, magnetic and vibrational properties of formamidine-templated Co and Fe formates

We report the synthesis, structure, magnetic and phonon properties of two novel [NH2-CH-NH2][M(HCOO)3] formates (M = Co, Fe). These compounds are isostructural and crystallize in the orthorhombic structure, space group Pnna, with ordered FMD+ cations located in the cavities of the network. They are weak ferromagnets, with the critical temperatures of 13.0 K (Co) and 17.0 K (Fe).