Synthesis, structure and host-guest properties of (Et4N)2[Sn(IV)Ca(II)(chloranilate)4], a new type of robust microporous coordination polymer with a 2D square grid structure.

Reaction of chloranilic acid with SnCl(4), Ca(NO(3))(2) and Et(4)NBF(4) in aqueous acetone yields (Et(4)N)(2)[Sn(IV)Ca(II)(can)(4)]. 2 Me(2)CO which contains 2D coordination polymer sheets of composition [Sn(IV)Ca(II)(can)(4)](2-). Both metals are 8-coordinate and act as 4-connecting nodes to form a square grid containing "square" holes.