title: Formation Mechanism and Reversible Expansion and Shrinkage of Magnesium-Based Homochiral Metal-Organic Nanotubes.
abstract: Two pairs of homochiral magnesium phosphonates, namely (R)-, (S)-[Mg(pemp)(H2O)2] (1) and (R)-, (S)-Mg10(pemp)10(H2O)10]⋅3 H2O (2) are reported (pemp2-=(R)- or (S)-(1-phenylethylamino) methylphosphonate). Compounds 1 show one-dimensional tubular structures. The tube wall is purely inorganic, containing six-membered rings made up of corner-sharing {MgO5N} octahedra and {PO3C} tetrahedra. The organic groups reside outside the tube. A bottom-up "direct growing" mechanism is proposed for the formation of the nanotubular structures of 1, based on the electrospray ionization mass spectrometry studies. Compounds 2 display two-dimensional layered structures containing cross-linked squashed nanotubes. Interestingly, the two structures can interconvert reversibly upon temperature and pH modulation. This is the first report of a metal-organic nanotube that can shrink and recover in a reversible manner.
authors.affiliation: State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P. R. China.
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P. R. China.
authors.forename: Jian-Shen
authors.initials: JS
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P. R. China.
authors.forename: Song-Song
authors.initials: SS
authors.lastname: Bao
authors.affiliation: State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P. R. China.
authors.forename: Li-Min
authors.identifier: http://orcid.org/0000-0003-4437-1105
authors.initials: LM
authors.lastname: Zheng
keywords: homochirality; magnesium; metal-organic nanotubes; phosphonates; structural modification