Guest Escape and Uptake in Nonporous Crystals of a Gold(I) Macrocycle

The nonporous gold(I) diphosphine complex [Au2(cis-dppe)2](NO3)2 [1, cis-dppe = cis-1,2-bis(diphenylphosphino)ethylene] is robust enough to trap guests, but at the same time, it is flexible enough to allow guest release without destruction of its crystal lattice. This nonporous gold(I) compound 1 is also efficient at capturing and releasing carbon dioxide in a controlled manner.