Basic Science

Breakthrough in Molecular Shuttles Based on Helix-Rod Assembly

An international team consists of the Jiang Hua research group of the Institute of Chemistry, CAS and the Ivan Huc group of the Institut Européen de Chimie et Biologie, France has developed a novel strategy for building molecular machines based on helix-rod assembly in which a helix wraps itself around a dumbbell-shaped molecule by dynamic assembly. Neither cyclizing nor capping reaction was required for this strategy. The assembly of helix-rod complexes is much faster than its dissociation. The helix-rod complexes are stable enough as long as the helix wraps itself around the rod. The motion of the helix along rod was demonstrated in the complex in which the helix can wrap around the rod with two identical stations and can reside in either station. The unidirectional motion was further realized by protonation or deprotonation of one of amine station. Before the protonation, the helix shows slight preference to stay on the hydrocarbon station than on the amine station (55:45). The shuttle process can be frozen upon the protonation of the amine station. In that case, the helix completely occupies the other binding site. The subsequent deprotonation can revive the motion of the helix. The work opens up a new pathway for constructing molecular machines with promising capacities. These results were published by Science (2011, 331, 1172-1175.) and were highlighted by Nature Chemistry (2011, 3(5), 338) and Chemical & Engineering News (March 7, 2011, 89(10), 42).

Galactic Anti-center Digital Sky Survey Program Completed

A team led by Prof. Liu Xiaowei from the Department of Astronomy and the Kavli Institute for Astronomy and Astrophysics of the Peking University, in collaboration with Profs. Zhao Haibin and Yao Jinsheng of the Xuyi Astronomical Observatory of the Purple Mountain Observatory, which owns and operates the Near Earth Object Survey Telescope，completed the data collection for a large CCD Photometric Survey of the GAC on March 8, 2011. The survey is considered as “outpost” of the Digital Sky Survey of the GAC, last 13 months from 2009 to 2011, using 15 to 20 dark/grey observational nights monthly. Milky Way is an archetypical giant spiral galaxy or disk galaxy. Revealing the formation and evolution history of disk galaxies in the bottom-up galaxy formation paradigm of the Lambda-CDM dominated cosmological framework is one of the most intriguing astrophysical issues of the 21st century. The Xuyi Schmidt photometric survey and the follow-up spectroscopic survey with the Guo Shoujing Telescope will provide a high quality huge amount of data set to tackle this forefront issue. Its successful completion will signify the arrival of Chinese astronomers at the central platform on the global stage and a transitional shift in world's center of gravity in observational astronomy, and will be a milestone in the history of Chinese observational astronomy.