Single File, Everyone (IMAGE) University of South Carolina Caption The building blocks that make up Shimizu's 'molecular straws' are cyclic organic compounds, which self-assemble into hollow tubes. The smaller ring (compound labeled 1; top) self-assembles into straws with narrow-bore interiors that can accommodate xenon atoms only in single file. Credit Adapted from <i>ACS Nano</i> Usage Restrictions Credit ACS Nano License Licensed 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.