Counter anion dependent gradual spin transition in a 1D cobalt(II) coordination polymer

One Co(II) SCO coordination polymer [Co(enbzpy)(μ1,5-dca)]n(PF6)n (1·PF6) has been isolated and characterised structurally and magnetostructurally. The properties of 1·PF6 are compared with the reported perchlorate analogue [Co(enbzpy)(μ1,5-dca)]n(ClO4)n (1·ClO4). The gradual spin transition in 1·PF6 in contrast to an abrupt spin transition with a hysteresis loop in 1·ClO4 has been analysed in terms of structural factors.