An organic anion template: a 24-nucleus silver cluster encapsulating a squarate dimer.

The first silver cluster encapsulating an organic anion-squarate dianion-has been synthesized. Two C4O4(2-) anions arranged in a staggered sandwich type arrangement are confined in the Ag24 cage. The incorporation of squarate anions into the silver alkynyl system leads to the red shift of absorption of the cluster in comparison to silver squarate.