Supramolecular polymers with tunable topologies via hierarchical coordination-driven self-assembly and hydrogen bonding interfaces

The platinum(II) complexes [PtCl(SMe2)(κ2-N,N′-L)]Cl and [PtMe(SMe2)(κ2-N,N′-L)]Cl, L = 2-C5H4NCH2NH-x-C6H4OH (x = 2, 3, or 4), have been prepared and structurally characterized. In all cases, the complexes form supramolecular polymers in the solid state by NH··Cl and OH··Cl hydrogen bonding to the chloride anion. The ligands are chiral at the amine nitrogen atom, and in all cases, the polymers are isotactic, formed by self-recognition or narcissistic self-assembly. The structures in the crystalline state all have the Me2S ligand trans to pyridyl, but in solution, the methylplatinum(II) complexes isomerise slowly to give an equilibrium with the isomers having the methyl group trans to the pyridyl donor.

Download Full-text

Photoresponsive Supramolecular Polymers: Halogen Bonding versus Hydrogen Bonding in Driving Self-Assembly and Performance of Light-Responsive Supramolecular Polymers (Adv. Funct. Mater. 12/2012)

Advanced Functional Materials ◽

10.1002/adfm.201290069 ◽

2012 ◽

Vol 22 (12) ◽

pp. 2571-2571 ◽

Cited By ~ 1

Author(s):

Arri Priimagi ◽

Gabriella Cavallo ◽

Alessandra Forni ◽

Mikael Gorynsztejn-Leben ◽

Matti Kaivola ◽

...

Keyword(s):

Hydrogen Bonding ◽

Self Assembly ◽

Halogen Bonding ◽

Supramolecular Polymers ◽

And Performance

Download Full-text

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

Molecules ◽

10.3390/molecules26134097 ◽

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.

Download Full-text

Tweaking a BODIPY Spherical Self‐Assembly to 2D Supramolecular Polymers Facilitates Excited State Cascade Energy Transfer

Angewandte Chemie International Edition ◽

10.1002/anie.202015390 ◽

2021 ◽

Author(s):

Gourab Das ◽

Sandeep Cherumukkil ◽

Akhil Padmakumar ◽

Vijay B. Banakar ◽

Vakayil K. Praveen ◽

...

Keyword(s):

Energy Transfer ◽

Excited State ◽

Self Assembly ◽

Supramolecular Polymers ◽

Cascade Energy

Download Full-text

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

Molecules ◽

10.3390/molecules26154705 ◽

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.

Download Full-text