Incorporation of Switchable Inorganic Building Blocks into Heterometallic Coordination Polymers

Abstract

A new terpyridine-based ligand with a pyridyl-1,2,4-triazoyl bidentate pocket “out the back” has been used to synthesize monometallic CoII, FeII, and RuII complexes where the octahedral metal is bound in a N6 bis-terpyridine coordination sphere. All four complexes ([MII(Lpyrtz-tpy)2](X)2 where MII = FeII, RuII, CoII with X = BF4-, or MII = CoII with X = PF6-) were structurally characterized confirming the expected bis-terpyridine coordination sphere. The monometallic complexes all show reversible MII/III redox processes, while the CoII complexes also undergo a slow spin crossover over the temperature range 50 K - 350 K. Utilizing the free triazole-pyridine bidentate pocket we show the ability of these complexes to act as supramolecular building blocks able to form 1D and 2D coordination polymers, {[MIIMI(Lpyrtz-tpy)2(MeCN)m]X3}n, with MI being CuI or AgI metal ions, MII = CoII, FeII, or RuII, X = BF4 or PF6, and m = 0 or 1, all five of which were structurally characterized.