Search

A temperature- and anion-induced coordination-driven self-assembly system based on a dynamic Ag6L4 metallocage was developed. Induced by SbF6− anions, both kinetically controlled [Ag3L2(SbF6)3] n and thermodynamically controlled [Ag2L2(SbF6)2] n can be reassembled from discrete Ag6L4(SbF6)6 metallocages at 30 °C, and increasing the temperature to 40 °C results in selective inhibition of the kinetic product. Under the influence of BF4− anions, dynamic Ag6L4(BF4)6 metallocages self-assemble into the thermodynamically controlled polycage at 25 °C, and lowing the temperature to 0 °C leads to selective inhibition of the thermodynamic product. Thus, both kinetically and thermodynamically controlled assembly processes in a dynamic system can be selectively driven by suitable external stimuli. [ABSTRACT FROM AUTHOR]

Three new compounds, CuL, CuL′, and Cu2O2L′′2 (H2L=3′-[( E)-{[(1 S,2 S)-2-aminocyclohexyl]imino}methyl]-4′-hydroxy-4-biphenylcarboxlic acid, H2L′=3′-[( E)-{[(1 S,2 S)-2-aminocyclohexyl]imino}methyl]-4′-hydroxy-5′-nitro-4-biphenylcarboxlic acid, H2L′′=3′-( N, N-dimethylamino methyl)-4′-hydroxy-4-biphenylcarboxlic acid), were selectively synthesized through a controlled in situ ligand reaction system mediated by copper(II) nitrate and H2L. Selective nitration was achieved by using different solvent mixtures under relatively mild conditions, and an interesting and economical reductive amination system in DMF/EtOH/H2O was also found. All crystal structures were determined by single-crystal X-ray diffraction analysis. Both CuL and CuL′ display chiral 1D chain structures, whereas Cu2O2L′′2 possesses a structure with 13×16 Å channels and a free volume of 41.4 %. The possible mechanisms involved in this in situ ligand-controlled reaction system are discussed in detail. [ABSTRACT FROM AUTHOR]