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Group Meeting
Literature
Emission Enhancement and Chromism in a Salen-Based Gel
SystemPeng Chen, Ran Lu, Pengchong Xue, Tinghua Xu, Guojun Chen,
Yingying Zhao
Ran Lu• Jilin University• State Key Laboratory of
Supramolecular Structure and Materials
• 130 papers on Sci-Finder• 9 Mater. Chem. Phys.• 5 Langmuir• 5 J. Mater. Research• Various other ACS papers
Emission Enhancement and Chromism in a Salen-Based Gel
System• Functional gelsenhanced charge
transport, fluorescence, catalysis, sensing abilities
• States that: “self-assembled properties of metal-salen complexes remains unexplored in the field of gels, although…”
J Aggregates
• Salphen aggregates exhibit J-bands (bathochromic shift)
• What about a gel system with thermochromism properties, based on salphen/salen type molecules with various metals?
The Molecule
• Cholesterol-containing salen-based gelator• Excellent organogelator in cyclohexane,
benzene, toluene, other mixed solvents
The SEM etc.
Reversible
• Cyclohexane gel = Colourless hot solutionyellow gel (as cooling)
• UV-Vis: Hot = 297 nm, 334 nm
• UV-Vis: RT = 480 nm
Reversible
Photochromism
• Irradiation of cyclohexane gel with 365 nm light with variable irradiation times
Fluorescence
• Fluorescence quantum yield is 600 times greater in gel than in solution 10-4 10-2
Summary
• New salen-based organogelator• Gels in several solvents• Moleculenanofibers3-D network• Aggregation-induced emission
enhancement (AIE) J-aggregates + no intramolecular rotation
• Solutionfaint blue; Gelbright green• Reversible chromism due to NH/OH
tautomerism
Supramolecular Assembly via Noncovalent Metal Coordination
Chemistry: Synthesis, Characterization, and Elastic
Properties
Christina Ott, Johannes M. Kranenburg, Carlos, Guerrero-Sanchez,Stephanie Hoeppener, Daan Wouters, Ulrich S. Schubert
Ulrich S. Schubert• 710 papers on Sci-Finder• 92 Polymer Pre-prints• 55 Macromol. Rapid Comm.• 20 Macromol. Chem. Phys.• 17 Macromolecules • 13 Adv. Mater.• 12 Soft Matter• 12 J. Mater. Chem.• 9 J. Comb. Chem.• 2 management assistants, 9 supporting
technical staff members, 9 guests (Dr.), 18 post-docs, 23 PhD students, 7 undergrads
Supramolecular Assembly
• Block co-polymers linked by Ru(II) complexes• Change elastic modulus of material by varying
chemical composition
Synthesis
• Styrene co-polymersinert atmosphere; 1,1-diphenylethylene + sec-butyllithium in cyclohexane (turn red) + styrene; then added 4’-chloro-2,2’:6’,2’’-terpyridine = SPSn-[
Synthesis A-Ru-B
Synthesis A-Ru-B-Ru-A
Micelles
• Polymers dissolved in THF and H2O added dropwise to induce aggregation of insoluble SPS block. More water added to “freeze” micelles.
• SPS39-[Ru]-PEG70
Structure-to-Function
• Flory-Huggins interaction parameter
• Volume fraction• Tailor mechanical properties by varying
block size
Structure-to-Function
Structure-to-Function
Structure-to-Function
• Indentation-load displacement response
Structure-to-Function• Increased % SPS = Increased stiffness• Decreased % [Ru], % PF6
- counterions• Humidity check