Low-dimensional compounds containing cyanido groups. Part XXXII. Field-induced multiple slow magnetic relaxation in [CoII(dcnm)(H2O)(phen)2](dcnm) complex with dominant easy-plane anisotropy (dcnm = dicyanonitrosomethanide)

Abstract Ionic cobalt(II) complex [Co(dcnm)(H 2 O)(phen) 2 ](dcnm) ( 1 ) (dcnm = dicyanonitrosomethanide, phen = 1,10-phenantroline) has been prepared by a diffusion technique. Its structure is formed by [Co(dcnm)(H 2 O)(phen) 2 ] + complex cation and free dcnm counterion in the lattice which acts as a hydrogen-bond acceptor to the hydrogen bonds from the water ligand coordinated to the Co atom. The Co atom is six-coordinated in the form of a distorted octahedron by two chelate phen molecules (one of them is disordered over two equivalent positions), one O-coordinated dcnm ligand and one water molecule which is cis -coordinated to O atom of dcnm ligand. The structure is stabilized by the system of hydrogen bonds and π–π interactions. Magnetic properties of 1 are dominated by a strong easy-plane anisotropy yielding to the energy difference between the two lowest Kramers doublets higher than 150 cm −1 . Two field-induced relaxation channels were observed by AC susceptibility study and were shown to be dominated by the direct spin-phonon relaxation at low temperatures. One of the relaxation channels is identified to be mediated by the electron-nuclear interaction.