Assembly of a Three-Dimensional Polyknotted Coordination Polymer

The coordination polymer {[Cd2(4,4‘-pytz)3(μ-NO3)(NO3)3(MeOH)]}∞, 1, displays a unique polyknotted structure in which each Cd(II) center is coordinated by three pyridyl N-donors arranged in an approximate T-shaped geometry to form a ladder motif. Within this structure, each ladder is interpenetrated perpendicularly by two other ladders. Significantly, each of the Cd(II) centers at the intersections of one ladder is bridged by a coordinated NO3 - anion to a Cd(II) center located at the corner of a square section of one of the perpendicularly interpenetrated ladders. Thus, all the ladders are linked together to give a three-dimensional polymer where the overall architecture is constructed of one molecule in a fused “polyknot”.