Self-assembly of discrete homochiral, helical, hydrogen-bonded nanocages: from vesicles to microspheres and tubules capable of gelating solvents.
The chiral tris-monodentate imidazolinyl ligands 1 a-c exhibit a strong tendency to form the discrete, helical [2+3] nanocages 3 ([1(2).2(3)]) with tartaric acids 2. Circular dichroism (CD) spectra and theoretical calculations reveal that supramolecular handedness of capsulelike architectures is determined only by the chirality of the imidazolinyl ligands rather than tartaric acids. The chirality of imidazolinyl ligands is transferred to the helicity of the complexes through the directed hydrogen bonds between the N3 atom of imidazoline rings and the carboxyl of tartaric acids. These hydrogen-bonded nanocages can spontaneously self-assemble into spherical vesicles, during which the hydrogen bonding that arises from the hydroxyl groups of tartaric acids plays a crucial issue. The vesicles formed by [{(S,S,S)-1 a}(2)(2(L))(3)] (3 a) may further evolve into microspheres that gelate organic solvents after being aged at -20 degrees C for 24 h, and can also be unprecedentedly transformed to tubular assemblies capable of rigidifying the solvents when subjected to ultrasound irradiation.
Yan
Liwei
L
Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Biotherapy, West China Medical School, Sichuan University, 29 Wangjiang Road, Chengdu 610064, P. R. China.
Xue
Ying
Y
Gao
Ge
G
Lan
Jingbo
J
Yang
Fan
F
Su
Xiaoyu
X
You
Jingsong
J
D018360:Crystallography, X-Ray; D005782:Gels / Q000737:chemistry*; D006860:Hydrogen Bonding; D007093:Imidazoles / Q000737:chemistry*; D008024:Ligands; D008863:Microspheres; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013237:Stereoisomerism
D005782:Gels; D007093:Imidazoles; D008024:Ligands; D012997:Solvents