[reaction: see text] Binding properties of a series of isomeric m-phenylene ethynylene oligomers containing short amide sequences to a piperazinium dihydrochloride salt were investigated by using circular dichroism (CD) measurements. Although these isomeric oligomers exhibited similar helical conformations, high affinity was observed only for one oligomer. This behavior is presumably controlled by the orientation of amino groups of the amide sequence and the folded conformation of the oligomer.
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http://dx.doi.org/10.1021/ol0500721 | DOI Listing |
Photochem Photobiol Sci
October 2023
Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, 525-8577, Japan.
Chlorophyll(Chl)-a derivatives inserting an ethynylene-m-phenylene group between a zinc chlorin ring and a hydroxymethyl group, in which various substituents were introduced on the benzene spacer, were prepared as model compounds for the light-harvesting antennae (chlorosomes) of photosynthetic green bacteria. These compounds were synthesized from a C3-ethynylated Chl-a derivative via sequential Sonogashira cross-coupling reaction, and the effects of the substituents on the phenylene linker on their self-aggregation behaviors were investigated by electronic absorption, circular dichroism, and infrared absorption spectroscopic measurements. These studies exhibited that some compounds gave the disordered self-assemblies including several species; however, the zinc complex of the dimeric Chl-a derivative primarily allowed a single J-aggregate species in an aqueous Triton X-100 micellar solution.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
July 2023
Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, P. R. China.
The construction of nanotubular structures with non-deformable inner pores is of both fundamental and practical significance. Herein we report a strategy for creating molecular nanotubes with defined lengths. Macrocyclic (MC) units based on shape-persistent hexakis(m-phenylene ethynylene) (m-PE) macrocycle MC-1, which are known to stack into hydrogen-bonded tubular assemblies, are tethered by oligo(β-alanine) linkers to give tubular stacks MC-2 and MC-4 that have two and four MC units, respectively.
View Article and Find Full Text PDFJ Org Chem
April 2023
Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.
We demonstrate the synthesis and chiroptical properties of doubled molecules of a chiral [1]rotaxane, based on the assembly of an achiral ring of a phenylacetylene macrocycle (6PAM) and a -phenylene ethynylene rod. Two molecules of [1]rotaxane constituted the doubled molecule through the ring fusion of 6PAMs to a 10PAM, which assured stationary occupation relative to each optically active unit. The absorption properties of the 10PAM-based doubled molecule and 6PAM-based original unit were consistently characterized by the independent existence of -phenylene ethynylene ring(s) and -phenylene ethynylene rod(s).
View Article and Find Full Text PDFChem Sci
August 2021
Yusuf Hamied Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
Oligomers equipped with complementary recognition units have the potential to encode and express chemical information in the same way as nucleic acids. The supramolecular assembly properties of -phenylene ethynylene polymers equipped with H-bond donor ( = phenol) and H-bond acceptor ( = phosphine oxide) side chains have been investigated in chloroform solution. Polymerisation of a bifunctional monomer in the presence of a monofunctional chain stopper was used for the one pot synthesis of families of -phenylene ethynylene polymers with sequences or ( = 1-5), which were separated by chromatography.
View Article and Find Full Text PDFSci Rep
April 2021
Department of Chemistry, University of Birjand, Birjand, Iran.
Hexakis (m-phenylene ethynylene) (m-PE) macrocycles, with aromatic backbones and multiple hydrogen-bonding side chains, had a very high propensity to self-assemble via H-bond and π-π stacking interactions to form nanotubular structures with defined inner pores. Such stacking of rigid macrocycles is leading to novel applications that enable the researchers to explored mass transport in the sub-nanometer scale. Herein, we performed density functional theory (DFT) calculations to examine the drug delivery performance of the hexakis dimer as a novel carrier for doxorubicin (DOX) agent in the chloroform and water solvents.
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