A Supramolecular Sorting Hat: Stereocontrol in Metal-Ligand Self-Assembly by Complementary Hydrogen Bonding

2014 ◽  
Vol 126 (37) ◽  
pp. 9990-9994 ◽  
Author(s):  
Michael C. Young ◽  
Lauren R. Holloway ◽  
Amber M. Johnson ◽  
Richard J. Hooley
2014 ◽  
Vol 53 (37) ◽  
pp. 9832-9836 ◽  
Author(s):  
Michael C. Young ◽  
Lauren R. Holloway ◽  
Amber M. Johnson ◽  
Richard J. Hooley

2014 ◽  
Vol 38 (5) ◽  
pp. 2135-2143 ◽  
Author(s):  
Louise B. Hamdy ◽  
Paul R. Raithby ◽  
Lynne H. Thomas ◽  
Chick C. Wilson

A series of magnesium pyridinecarboxylic–dicarboxylic acid complexes, synthesised as precursors to potential framework materials, show a range of metal ligand and hydrogen bonding geometries. The pyridinedicarboxylic complexes show most promise as precursors for further syntheses.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3598
Author(s):  
Nirmal K. Shee ◽  
Hee-Joon Kim

A series of porphyrin triads (1–6), based on the reaction of trans-dihydroxo-[5,15-bis(3-pyridyl)-10,20-bis(phenyl)porphyrinato]tin(IV) (SnP) with six different phenoxy Zn(II)-porphyrins (ZnLn), was synthesized. The cooperative metal–ligand coordination of 3-pyridyl nitrogens in the SnP with the phenoxy Zn(II)-porphyrins, followed by the self-assembly process, leads to the formation of nanostructures. The red-shifts and remarkable broadening of the absorption bands in the UV–vis spectra for the triads in CHCl3 indicate that nanoaggregates may be produced in the self-assembly process of these triads. The emission intensities of the triads were also significantly reduced due to the aggregation. Microscopic analyses of the nanostructures of the triads reveal differences due to the different substituents on the axial Zn(II)-porphyrin moieties. All these nanomaterials exhibited efficient photocatalytic performances in the degradation of rhodamine B (RhB) dye under visible light irradiation, and the degradation efficiencies of RhB in aqueous solution were observed to be 72~95% within 4 h. In addition, the efficiency of the catalyst was not impaired, showing excellent recyclability even after being applied for the degradation of RhB in up to five cycles.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4097
Author(s):  
Wooyong Seong ◽  
Hyungwoo Hahm ◽  
Seyong Kim ◽  
Jongwoo Park ◽  
Khalil A. Abboud ◽  
...  

Bimetallic bis-urea functionalized salen-aluminum catalysts have been developed for cyclic carbonate synthesis from epoxides and CO2. The urea moiety provides a bimetallic scaffold through hydrogen bonding, which expedites the cyclic carbonate formation reaction under mild reaction conditions. The turnover frequency (TOF) of the bis-urea salen Al catalyst is three times higher than that of a μ-oxo-bridged catalyst, and 13 times higher than that of a monomeric salen aluminum catalyst. The bimetallic reaction pathway is suggested based on urea additive studies and kinetic studies. Additionally, the X-ray crystal structure of a bis-urea salen Ni complex supports the self-assembly of the bis-urea salen metal complex through hydrogen bonding.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4705
Author(s):  
Boer Liu ◽  
Xi Chen ◽  
Glenn A. Spiering ◽  
Robert B. Moore ◽  
Timothy E. Long

This work reveals the influence of pendant hydrogen bonding strength and distribution on self-assembly and the resulting thermomechanical properties of A-AB-A triblock copolymers. Reversible addition-fragmentation chain transfer polymerization afforded a library of A-AB-A acrylic triblock copolymers, wherein the A unit contained cytosine acrylate (CyA) or post-functionalized ureido cytosine acrylate (UCyA) and the B unit consisted of n-butyl acrylate (nBA). Differential scanning calorimetry revealed two glass transition temperatures, suggesting microphase-separation in the A-AB-A triblock copolymers. Thermomechanical and morphological analysis revealed the effects of hydrogen bonding distribution and strength on the self-assembly and microphase-separated morphology. Dynamic mechanical analysis showed multiple tan delta (δ) transitions that correlated to chain relaxation and hydrogen bonding dissociation, further confirming the microphase-separated structure. In addition, UCyA triblock copolymers possessed an extended modulus plateau versus temperature compared to the CyA analogs due to the stronger association of quadruple hydrogen bonding. CyA triblock copolymers exhibited a cylindrical microphase-separated morphology according to small-angle X-ray scattering. In contrast, UCyA triblock copolymers lacked long-range ordering due to hydrogen bonding induced phase mixing. The incorporation of UCyA into the soft central block resulted in improved tensile strength, extensibility, and toughness compared to the AB random copolymer and A-B-A triblock copolymer comparisons. This study provides insight into the structure-property relationships of A-AB-A supramolecular triblock copolymers that result from tunable association strengths.


Author(s):  
Ganghuo Pan ◽  
Jie Leng ◽  
Liye Deng ◽  
Liwen Xing ◽  
Rui Feng

2003 ◽  
pp. 2278 ◽  
Author(s):  
Jing Tang ◽  
Henrik Birkedal ◽  
Eric W. McFarland ◽  
Galen D. Stucky

2007 ◽  
Vol 601 (16) ◽  
pp. L91-L94 ◽  
Author(s):  
Junseok Lee ◽  
Daniel B. Dougherty ◽  
John T. Yates

2008 ◽  
Vol 8 (6) ◽  
pp. 2996-3002 ◽  
Author(s):  
Liqin Ge ◽  
Xing Wang ◽  
Long Ba ◽  
Zhongze Gu

The hydrogen-bonding multilayered polyelectrolyte capsules with sizes around 6 μm were fabricated by layer-by-layer self-assembly method. The morphology of the obtained capsules was observed with Scanning Electron Microscope (SEM), Confocal Laser Scanning Microscope (CLSM) and Atomic Force Microscope (AFM), respectively. The elastic properties of the capsules were studied with AFM. The capsule was pressed by cantilever with different lengths, a glass bead glued at the end of the cantilever. The force curves were measured on the capsule in air. The Young's modulus of the capsule was obtained (E = 170 MPa for the loading). Results show that this model can predict the elastic deformation of the microcapsule. The accuracy of the elastic deformation of polymer capsule can be ensured using a cantilever of mediate stiffness. Our results show that the existence of the hydrogen-bonding layer makes the multilayered polyelectrolyte harder in comparison with the pure multilayered polyelectrolyte capsules.


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