The nickel carbene complex Ni1 was originally prepared to investigate the effect of structural changes upon the properties of N-heterocyclic carbene (NHC) complexes as catalysts for the electrochemical reduction of carbon dioxide. The first compound of this class was reported in 2004, with some more described in recent work by Su et al. In the initial CO-ADD screening this complex showed high activity against Cryptococcus spp. but none against the Candida spp. The complex was also effective at killing the Gram-positive methicillin resistant Staphylococcus aureus (MRSA), but was not active against any of the Gram-negative strains tested (Table ). The selectivity in antifungal activity is maintained in the extended panel with Ni1 showing good activity against all the Cryptococcus spp, but no measurable effect against the Candida strains except C. auris. The complex also showed no toxicity or haemolysis up to the highest concentration measured, 160 µM. This heterogeneity in the activity profile of this compound is notable as it is the only complex in this data set that shows this behaviour.