Crystal structure of an antiferromagnetically coupled µ-carbonato-bridged dinickel( II ) complex containing the pendent-arm macrocycl 1-(3-dimethylaminopropyl)-1,5,9-triazacyclododecane (L 1 ); a system which readily sequesters carbon dioxide from air

The nickel(II) complex of the pendent-arm macrocycle 1-(3-dimethylaminopropyl)-1,5,9-triazacyclododecane (L1) sequesters CO2 from air to yield, after addition of thiocyanate ion, [{(HL1)Ni(NCS)}2(CO3)]2+, the first example of a µ-carbonato dinickel(II) complex; the Ni atoms are antiferromagnetically coupled with the exceptionally large exchange constant –2J= 94.6 ± 0.4 cm–1.