Self-Assembly of a Porphyrin Array via the Molecular Recognition Approach:  Synthesis and Properties of a Cyclic Zinc(II) Porphyrin Trimer Based on Coordination and Hydrogen Bonding

2001 ◽  
Vol 40 (14) ◽  
pp. 3395-3405 ◽  
Author(s):  
Chusaku Ikeda ◽  
Yuichi Tanaka ◽  
Takeshi Fujihara ◽  
Yoko Ishii ◽  
Takeshi Ushiyama ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Recognition ◽  
Self Assembly

Molecular-Recognition-Directed Self-Assembly of Pleated Sheets from 2-Aminopyrimidine Hydrogen-Bonding Motifs

1998 ◽  
Vol 81 (11) ◽  
pp. 1909-1920 ◽  
Author(s):  
Michael J. Krische ◽  
Jean-Marie Lehn ◽  
Nathalie Kyritsakas ◽  
Jean Fischer
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Recognition ◽  
Self Assembly

ChemInform Abstract: Molecular-Recognition-Directed Self-Assembly of Pleated Sheets from 2-Aminopyrimidine Hydrogen-Bonding Motifs.

ChemInform ◽  
2010 ◽  
Vol 30 (8) ◽  
pp. no-no
Author(s):  
M. J. KRISCHE ◽  
J.-M. LEHN ◽  
N. KYRITSAKAS ◽  
J. FISCHER
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Recognition ◽  
Self Assembly

scholarly journals Self-Assembled Bimetallic Aluminum-Salen Catalyst for the Cyclic Carbonates Synthesis

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4097
Author(s):  
Wooyong Seong ◽  
Hyungwoo Hahm ◽  
Seyong Kim ◽  
Jongwoo Park ◽  
Khalil A. Abboud ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Reaction Pathway ◽  
Kinetic Studies ◽  
Cyclic Carbonate ◽  
Reaction Conditions ◽  
Formation Reaction ◽  
X Ray ◽  
Carbonate Formation ◽  
Salen Aluminum

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.

scholarly journals Quadruple Hydrogen Bond-Containing A-AB-A Triblock Copolymers: Probing the Influence of Hydrogen Bonding in the Central Block

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4705
Author(s):  
Boer Liu ◽  
Xi Chen ◽  
Glenn A. Spiering ◽  
Robert B. Moore ◽  
Timothy E. Long
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Microphase Separation ◽  
Triblock Copolymers ◽  
Random Copolymer ◽  
Thermomechanical Properties ◽  
Structure Property ◽  
Scanning Calorimetry ◽  
Central Block ◽  
Quadruple Hydrogen Bonding

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.

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