Long bipyridyl-type linking ligands containing an intervening cyclohexyl fragment and their cadmium coordination polymers: image and image (Ln = (n-py)–CHdouble bond; length as m-dashN–C6H10–Ndouble bond; length as m-dashCH–(n-py); n = 4, 3, 2)

We prepared three isomeric bipyridyl-type ligands (Ln = (n-py)–CHdouble bond; length as m-dashN–C6H10–Ndouble bond; length as m-dashCH–(n-py); n = 2–4). Two cadmium coordination polymers, image (1) and image (2), were prepared from cadmium nitrate and ligands L4 and L3, respectively. The N⋯N separations between the two terminal pyridyl groups in the free ligands L4, L3, and L2 are 15.798(6), 15.036(4), and 12.417(5) Å, respectively. The 2-D α-arsenic-type polymer 1, which contains CH2Cl2 guest molecules, has two distinct N⋯N separations of 15.706(10) Å and 14.479(9) Å and a large 102-membered cyclohexane-like ring unit. The 1-D stair-like polymer 2 has also two distinct N⋯N separations and a 60-membered ring unit. The various lengths of the observed N⋯N separations are due to the ring flip of the intervening cyclohexyl fragment in the ligands.