The di-copper(II) analogue, [CuII2(bis-LEt)](BF4)2 (2), of the previously reported mono-copper(II) complex [CuIILEt]BF4 (1) which resulted in long lived electrocatalytic hydrogen evolution reaction (HER), has been prepared, characterised and tested for...

A new terpyridine-based ligand with a pyridyl-1,2,4triazoyl bidentate pocket "out the back" has been used to synthesize monometallic Co II , Fe II , and Ru II complexes where the octahedral metal is bound in a N 6 bis-terpyridine coordination sphere. All four complexes ([M II (L pyrtz-tpy ) 2 ](X) 2 where M II = Fe II , Ru II , Co II with X = BF 4 − , or M II = Co II with X = PF 6 − ) were structurally characterized confirming the expected bis-terpyridine coordination sphere. The monometallic complexes all show reversible M II/III redox processes, while the Co II 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, {[M II M I (L pyrtz-tpy ) 2 (MeCN) m ]X 3 } n , with M I being Cu I or Ag I metal ions, M II = Co II , Fe II , or Ru II , X = BF 4 or PF 6 , and m = 0 or 1, all five of which were structurally characterized.