A coordinatively saturated sulfate encapsulated in a metal–organic framework functionalized with urea hydrogen-bonding groups

A functional coordination polymer decorated with urea hydrogen-bonding donor groups has been designed for optimal binding of sulfate; self-assembly of a tripodal tris-urea linker with Ag2SO4 resulted in the formation of a 1D metal–organic framework that encapsulates SO4^2– anions via twelve complementary hydrogen bonds, which represents the highest coordination number observed for sulfate in a natural or synthetic host.