Capture of di-protonated [2.2.2]cryptand in the cavity of two p-sulfonated calixarenes as part of 2-D bi-layer lanthanide coordination polymers

Treating p-sulfonatocalix[4]arene with lanthanide ions, Ln(3+) (Ln = Ce, Nd, Sm and Eu), in the presence of [2.2.2]cryptand results in a 2-D bi-layer coordination polymer with axially elongated diprotonated cryptand in the cavity of two p-sulfonatocalix[4]arenes.