Building block of catena-COF (IMAGE) University of California - Berkeley Caption The building block of an infinite catenane, or catena-COF, consists of two crossed molecules with a copper atom at the center. When mixed, they link up to create an extended, 3D material of interlocking molecules. Credit Tianqiong Ma, UC Berkeley Usage Restrictions none License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.