keyword
MENU ▼
Read by QxMD icon Read
search

Supramolecular

keyword
https://www.readbyqxmd.com/read/29143770/surface-relief-gratings-in-halogen-bonded-polymer-azobenzene-complexes-a-concentration-dependence-study
#1
Jelle E Stumpel, Marco Saccone, Valentina Dichiarante, Ossi Lehtonen, Matti Virkki, Pierangelo Metrangolo, Arri Priimagi
In recent years, supramolecular complexes comprising a poly(4-vinylpyridine) backbone and azobenzene-based halogen bond donors have emerged as a promising class of materials for the inscription of light-induced surface-relief gratings (SRGs). The studies up to date have focused on building supramolecular hierarchies, i.e., optimizing the polymer-azobenzene noncovalent interaction for efficient surface patterning. They have been conducted using systems with relatively low azobenzene content, and little is known about the concentration dependence of SRG formation in halogen-bonded polymer-azobenzene complexes...
October 28, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29143006/cooperative-supramolecular-polymerization-of-a-perylene-diimide-derivative-and-its-impact-on-electron-transporting-properties
#2
Dipankar Basak, Deep Sankar Pal, Tsuneaki Sakurai, Satoru Yoneda, Shu Seki, Suhrit Ghosh
H-bonding-promoted supramolecular polymerization of a perylene diimide (PDI) building block and its impact on charge carrier mobility were studied. PDI-1, containing a carboxylic acid group, exhibits H-aggregation in a non-polar solvent decalin while in THF or chloroform it remains in the monomeric form. In contrast, the control molecule PDI-2, containing an ester group does not show aggregation even in decalin, indicating that H-bonding among the carboxylic acid is primarily responsible for H-aggregation, which is further verified by the FT-IR study...
November 16, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29142998/covalent-post-assembly-modification-in-metallosupramolecular-chemistry
#3
REVIEW
Derrick A Roberts, Ben S Pilgrim, Jonathan R Nitschke
A growing variety of covalent reactions have been employed to achieve the post-assembly modification (PAM) of self-assembled metallosupramolecular complexes. Covalent PAM enables the late-stage derivatisation of pre-assembled parent complexes in a modular fashion, thus expanding the chemical space available for supramolecular synthesis. The oldest and most widespread implementation of covalent PAM is in metal-preorganised covalent synthesis. Recent work, however, has broadened the scope of covalent PAM to include: protocols for efficiently grafting new functionalities onto supramolecular architectures, reactions that permanently 'lock-down' metastable complexes, and covalent bond-forming stimuli that trigger controlled structural transformations between distinct supramolecular species...
November 16, 2017: Chemical Society Reviews
https://www.readbyqxmd.com/read/29141412/formation-of-supramolecular-protein-structures-on-gold-surfaces
#4
Laura J Domigan, Helen Ashmead, Simone Dimartino, Jenny Malmstrom, F Grant Pearce, Matthew Blunt, David E Williams, Juliet A Gerrard
Recent research has highlighted the exciting possibilities enabled by the use of protein structures as nanocomponents to form functional nanodevices. To this end, control over protein-protein and protein-surface interactions is essential. In this study, the authors probe the interaction of human peroxiredoxin 3 with gold surfaces, a protein that has been previously identified as having potential use in nanotechnology. Analytical ultracentrifugation and transmission electron microscopy revealed the pH mediated assembly of protein toroids into tubular structures across a small pH range...
November 15, 2017: Biointerphases
https://www.readbyqxmd.com/read/29141223/gradients-of-rac1-nanoclusters-support-spatial-patterns-of-rac1-signaling
#5
Amanda Remorino, Simon De Beco, Fanny Cayrac, Fahima Di Federico, Gaetan Cornilleau, Alexis Gautreau, Maria Carla Parrini, Jean-Baptiste Masson, Maxime Dahan, Mathieu Coppey
Rac1 is a small RhoGTPase switch that orchestrates actin branching in space and time and protrusion/retraction cycles of the lamellipodia at the cell front during mesenchymal migration. Biosensor imaging has revealed a graded concentration of active GTP-loaded Rac1 in protruding regions of the cell. Here, using single-molecule imaging and super-resolution microscopy, we show an additional supramolecular organization of Rac1. We find that Rac1 partitions and is immobilized into nanoclusters of 50-100 molecules each...
November 14, 2017: Cell Reports
https://www.readbyqxmd.com/read/29141145/homochiral-versus-heterochiral-trifluoromethylated-pseudoproline-containing-dipeptides-a-powerful-tool-to-switch-the-prolyl-amide-bond-conformation
#6
Grégory Chaume, Julien Simon, Nathalie Lensen, Julien Pytkowicz, Thierry Brigaud, Emeric Miclet
The design of constrained peptides is of prime importance in the development of bioactive compounds and for applications in supramolecular chemistry. Due to its nature, the peptide bond undergoes a spontaneous cis-trans isomerism and the cis isomers are much more difficult to stabilize than the trans forms. By using oxazolidine-based pseudoprolines (ΨPro) substituted by a trifluoromethyl group, we show that the cis peptide bond can be readily switched from 0% to 100% in Xaa-ΨPro dipeptides. Our results prove that changing the configuration of the Cα in Xaa or in ΨPro is sufficient to invert the cis:trans populations while changing the nature of the Xaa side chain finely tuned the conformers ratio...
November 15, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/29141117/tunable-energy-landscapes-to-control-pathway-complexity-in-self-assembled-n-heterotriangulenes-living-and-seeded-supramolecular-polymerization
#7
Jorge S Valera, Rafael Gómez, Luis Sánchez
Herein, the synthesis and self-assembling features of N-heterotriangulenes 1-3 decorated in their periphery with 3,4,5-trialkoxy-N-(alkoxy)benzamide moieties that enable kinetic control of the supramolecular polymerization process are described. The selection of an appropriate solvent results in a tunable energy landscape in which the relative energy of the different monomeric or aggregated species can be regulated. Thus, in a methylcyclohexane/toluene (MCH/Tol) mixture, intramolecular hydrogen-bonding interactions in the peripheral side units favor the formation of metastable inactivated monomers that evolve with time at precise conditions of concentration and temperature...
November 15, 2017: Small
https://www.readbyqxmd.com/read/29140680/helicity-inversion-of-supramolecular-hydrogels-induced-by-achiral-substituents
#8
Guofeng Liu, Xin Li, Jianhui Sheng, Pei-Zhou Li, Wee Kong Ong, Soo Zeng Fiona Phua, Hans Ågren, Liangliang Zhu, Yanli Zhao
Probing the supramolecular chirality of assemblies and controlling their handedness are closely related to the origin of chirality at supramolecular level and the development of smart materials with desired handedness. However, it remains unclear how achiral residues covalently bonded to chiral amino acids can function in the chirality inversion of supramolecular assemblies. Herein, we report macroscopic chirality and dynamic manipulation of chiroptical activity of hydrogels self-assembled from phenylalanine derivatives, together with the inversion of their handedness achieved solely by exchanging achiral substituents between oligo(ethylene glycol) and carboxylic acid groups...
November 15, 2017: ACS Nano
https://www.readbyqxmd.com/read/29140078/molecular-recognition-and-immobilization-of-ligand-conjugated-redox-responsive-polymer-nanocontainers
#9
Wilke De Vries, Matthias Tesch, Armido Studer, Bart Jan Ravoo
We present the preparation of ligand conjugated redox-responsive polymer nanocontainers by the supramolecular decoration of cyclodextrin vesicles with a thin redox-cleavable polymer shell that displays molecular recognition units on its surface. Two widely different recognition motifs (mannose-Concanavalin A and biotin-streptavidin) are compared and the impact of ligand density is studied using aggregation assays, dynamic light scattering, and a fluorometric quantification of ligands. Microcontact printing is used to prepare streptavidin-patterned surfaces and the specific immobilization of biotin conjugated nanocontainers is demonstrated...
November 15, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29140068/arginine-rich-peptide-induced-supramolecular-self-assembly-of-water-soluble-anionic-alkynylplatinum-ii-complexes-a-continuous-and-label-free-luminescence-assay-for-trypsin-and-inhibitor-screening
#10
Angela Sin-Yee Law, Margaret Ching-Lam Yeung, Vivian Wing-Wah Yam
A water-soluble anionic alkynylplatinum(II) 2,6-bis(benzimidazol-2'-yl)pyridine (bzimpy) complex has been strategically designed and synthesized to show supramolecular self-assembly with cationic arginine-rich peptides through unique noncovalent Pt(II)···Pt(II) and π-π stacking interactions. Upon introduction of trypsin, the arginine-rich peptides can be hydrolyzed into small fragments and deaggregation of the platinum(II) complex molecules is observed. The aggregation-deaggregation process has been probed by UV-vis absorption, emission, and resonance light scattering (RLS) studies...
November 15, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29139491/supramolecular-block-copolymers-for-gene-delivery-enhancement-of-transfection-efficiency-by-charge-regulation
#11
Wumaier Yasen, Ruijiao Dong, Linzhu Zhou, Yu Huang, Dongbo Guo, Dong Chen, Chuanlong Li, Aliya Aini, Xinyuan Zhu
A class of cationic supramolecular block copolymers with readily controlled charges has been exploited. Upon post-synthetic structural optimization, this copolymer exhibits comparable biocompatibility, greatly improved pDNA condensation capability and biostability, and further enhanced transfection efficiency in vitro. This work provides valuable insight into the creation of advanced nonviral vectors for gene delivery.
November 15, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/29138773/cooperating-dipole-dipole-and-van-der-waals-interactions-driven-2d-self-assembly-of-fluorenone-derivatives-ester-chain-length-effect
#12
Meiqiu Dong, Kai Miao, Yi Hu, Juntian Wu, Jinxing Li, Peng Pang, Xinrui Miao, Wenli Deng
Two-dimensional supramolecular assemblies of a series of 2,7-bis(10-n-alkoxycarbonyl-decyloxy)-9-fluorenone derivatives (BAF-Cn, n = 1, 3-6) consisting of polar fluorenone moieties and ester alkoxy chains were investigated by scanning tunneling microscopy on highly oriented pyrolytic graphite surfaces. The chain-length effect was observed in the self-assembly of BAF-Cn. Self-assembly of BAF-C1 was composed of a linear I pattern, where the side chains adopted a fully interdigitated arrangement. As the length of side chains increased, the coexistence of a linear I pattern and a cyclic pattern for the self-assembly of BAF-C3 was observed...
November 15, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29137799/ultrasound-irradiation-effect-on-morphological-properties-of-a-3d-nano-zinc-ii-supramolecular-coordination-polymer
#13
Hai Ning Chang, Suo Xia Hou, Zeng Chuan Hao, Guang Hua Cui
Nano-structures of [Zn(L)(atpt)]n (1) (L=1,2-bis(2-methylbenzimidazol-1-ylmethyl)benzene and H2atpt=2-aminoterephthalic acid) were obtained by hydrothermal and sonochemical approaches, characterized by scanning electron microscopy (SEM), IR, powder X-ray diffraction (PXRD), and elemental analysis. CP 1 features a 2D (4,4) network with the point symbol {4(4).6(2)}, the 3D supramolecular architecture in CP 1 is controlled through π⋯π stacking interactions. The influence of various concentrations of initial reagents, power of ultrasound irradiation, and ultrasound time on the morphology and size of nano-structured CP 1 were studied in detail...
March 2018: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/29137791/sonochemical-synthesis-and-characterization-of-new-seven-coordinated-zinc-cadmium-and-mercury-nitrate-complexes-new-precursors-for-nanostructure-metal-oxides
#14
S Mojahedi Jahromi, M Montazerozohori, A Masoudiasl, E Houshyar, S Joohari, J M White
The nitrate complexes of group 12 elements with a tridentate Schiff base ligand (L = (E)-N1-((E)-3- phenylallylidene)-N2-(2-((E)-((E)-3-phenylallylidene) amino)ethyl) ethane-1,2-diamine) were synthesized via sonochemical process and characterized by various physical and chemical methods. The structural analysis of the zinc nitrate complex by single crystal X-ray diffraction analysis shows that the central atom is seven-coordinated by three nitrogen atoms from the Schiff base ligand as well as four oxygen atoms from two different nitrate anions...
March 2018: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/29137744/luminescence-electrochemical-and-photocatalytic-properties-of-sub-micron-nickel-ii-and-cobalt-ii-coordination-polymers-synthesized-by-sonochemical-process
#15
Jun Xuan Li, Yu Feng Li, Li Wei Liu, Guang Hua Cui
Submicron structures of Ni(II)/Co(II)-based coordination polymers (CPs) [Ni(L1)(mip)·H2O]n (1) and {[Co(L2)(mip)]·0·.5H2O}n(2) (L1=1,6-bis(5,6-dimethylbenzimidazole)hexane, L2=1,6-bis(benzimidazole)hexane, H2mip=5-methylisophthalic acid) were obtained by ultrasonic irradiation and structurally characterized by elemental analysis, powder X-ray diffraction and scanning electron microscopy. Structural analysis show that two CPs feature uninodal 3-connected 2D hcb layer, whilst CP 2 is further extended into a 3D complicated supramolecular network by C14-H14⋯O2 hydrogen bonds...
March 2018: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/29137733/three-dimensional-organometallic-thallium-i-supramolecular-polymer-nanostructures-synthesized-with-sonochemical-process
#16
Maryam Moeinian, Kamran Akhbari, Jaursup Boonmak, Sujittra Youngme
A new three-dimensional thallium(I) supramolecular polymer, [Tl2(μ2-ATA)]n (1), [H2ATA=2-aminoterephthalic acid], has been synthesized and characterized. The single-crystal X-ray data of compound 1 shows one type of Tl(I) ion with a low coordination number. Compound 1 was self-assembled from Tl⋯C, Tl⋯O and Tl⋯N secondary interactions in thallium(I) coordination and the active lone pair on Tl(I) in this compound may be involved in donor bonding. Two sides of the aromatic ring of ATA(2-) anion have been involved in two types of secondary Tl⋯C approaches...
March 2018: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/29135264/peptide-based-polymer-polyoxometalate-supramolecular-structure-with-differed-antimicrobial-mechanism
#17
Lakshmi Priya Datta, Riya Mukherjee, Subharanjan Biswas, Tapan Kumar Das
Because of the increasing prevalence of multi-drug resistance feature, several investigations have been so far reported regarding the antibiotic alternative supramolecular bioactive agents made of hybrid assemblies. In this regard, it is well established that combinational therapy inherited by assembled supramolecular structures can improve the bioactivity to some extent but their mode of actions have not been studied in details. We provide the first direct evidence that the improved mechanism of action of antimicrobial supra-amphiphilic nanocomposites differ largely from their parent antimicrobial peptide based polymers...
November 14, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/29135262/a-low-molecular-weight-gelator-composed-of-pyrene-and-fluorene-moieties-for-effective-charge-transfer-in-supramolecular-ambidextrous-gel
#18
Samala Murali Mohan Reddy, Pramod Dorishetty, George Augustine, Abhijit P Deshpande, Niraikulam Ayyadurai, Ganesh Shanmugam
Charge-transfer (CT) gel materials obtained from low-molecular-weight (LMW) compounds through a supramolecular self-assembly approach have received fascinating attention by many researchers because of their interesting material property and potential applications. However, most of the CT gel materials constructed were of organogels while the construction of CT gels in the form of a hydrogel is a challenge because of the solubility issue in water, which considerably limits the use of CT hydrogels. Herein, for the first time, we report a new LMW gelator [N(α)-(fluorenylmethoxycarbonyl)-N(ε)-(δ-butyric-1-pyrenyl)-l-lysine, (FmKPy)], composed of two functional moieties such as fluorenylmethoxycarbonyl and pyrene, which not only parade both hydro and organo (ambidextrous) supramolecular gel formation but also exhibit CT ambidextrous gels when mixed with an electron acceptor such as 2,4,7-trinitro-9-fluorenone (TNF)...
November 14, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/29135011/hierarchical-self-assembly-of-enantiopure-and-racemic-helicenes-at-the-liquid-solid-interface-from-2d-to-3d
#19
Hai Cao, Andrea Minoia, Inge De Cat, Johannes Seibel, Deepali Waghray, Zhi Li, David Cornil, Kunal S Mali, Roberto Lazzaroni, Wim Dehaen, Steven De Feyter
The performance of organic nanostructures is closely related to the organization of the functional molecules. Frequently, molecular chirality plays a central role in the way molecules assemble at the supramolecular level. Herein we report the hierarchical self-assembly of benzo-fused tetrathia[7]helicenes on solid surfaces, from a single surface-bound molecule to well-defined microstructures, using a combination of various characterization techniques assisted by molecular modeling simulations. Similarities as well as discrepancies are revealed between homochiral and heterochiral aggregations by monitoring the hierarchical nucleation of helicenes on surfaces, where the impact of enantiopurity, concentration and adsorbate-substrate interaction on molecular organization are disclosed...
November 14, 2017: Nanoscale
https://www.readbyqxmd.com/read/29133814/structural-remodeling-and-oligomerization-of-human-cathelicidin-on-membranes-suggest-fibril-like-structures-as-active-species
#20
Enea Sancho-Vaello, Patrice François, Eve-Julie Bonetti, Hauke Lilie, Sebastian Finger, Fernando Gil-Ortiz, David Gil-Carton, Kornelius Zeth
Antimicrobial peptides as part of the mammalian innate immune system target and remove major bacterial pathogens, often through irreversible damage of their cellular membranes. To explore the mechanism by which the important cathelicidin peptide LL-37 of the human innate immune system interacts with membranes, we performed biochemical, biophysical and structural studies. The crystal structure of LL-37 displays dimers of anti-parallel helices and the formation of amphipathic surfaces. Peptide-detergent interactions introduce remodeling of this structure after occupation of defined hydrophobic sites at the dimer interface...
November 13, 2017: Scientific Reports
keyword
keyword
89465
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"