Non-Interpenetrated Square-Grid Coordination Polymers Synthesized Using an Extremely Long <i>N</i>,<i>N</i>‘-Type Ligand

Four new, non-interpenetrated square-grid coordination polymers, namely [Mn(L)2(NO3)2]∞ (1), {[Cd(L)2(NO3)2]·solvate}∞ (2), [Cd(L)2(NO3)2]∞ (3), and {[Zn(L)2](BF4)2·(C6H6)2.564·(DMF)1.576·(MeOH, H2O)3.454}∞ (4), were synthesized using the new, extremely long N,N‘-type ligand: 2,5-bis(4‘-(imidazol-1-yl)benzyl)-3,4-diaza-2,4-hexadiene (L). The reaction of Cd(NO3)2 with L leads to two novel structures sharing the same framework composition, [Cd(L)2(NO3)2]∞, which have different arrangements of L around the metal centers. Both the channel-containing structure and the nonporous structure can be formed by choice of the appropriate solvent system. Moreover, the less stable, channel-containing form readily converts into the more stable, condensed structure upon removal of the guest molecules from the channels.