New Fe-II guest-dependent spin crossover (SCO) coordination polymers, {Fe(II)4-(3-pentyl) pyridine2[Au-I(CN)(2)](2)center dot(guest)} n (guest = 4-(3-pentyl)pyridine (1a), non-guest (1b)) has been prepared and investigated by magnetic measurement and X-ray structure analysis. The adsorbed state has a two-step transition with a broad temperature-range intermediate state, whereas the desorbed state has a one-step transition. 1b is maintained HS state down to around 200 K. Below this temperature, 1b displays nearly 50% one-step transition. The first transition of 1a starts below ca. 280 K and almost completes at ca. 210 K. Below around 120 K, second transition starts and completes around 65 K, which 50% of high-spin is remaining. Interlayer spaces between two dimensional sheets are greater than other similar 2D Hoffman-like clathrates. (C) 2015 Elsevier B.V. All rights reserved.