scholarly journals Copolymers and Hybrids Based on Carbazole Derivatives and Their Nanomorphology Investigation

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 133 ◽  
Author(s):  
Stefania Aivali ◽  
Sofia Kakogianni ◽  
Charalampos Anastasopoulos ◽  
Aikaterini Andreopoulou ◽  
Joannis Kallitsis
Keyword(s):  
Optical Properties ◽  
Free Radical ◽  
Band Gap ◽  
Electron Donor ◽  
Carbon Nanostructures ◽  
Polymeric Materials ◽  
Covalent Attachment ◽  
Carbazole Derivatives ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Oligomers of the low-band-gap PCDTBT polymer, based on either 3,6 or 2,7 carbazole units, were modified with vinyl ω-chain end functionalities. The vinyl-functionalized oligomers were used as comonomers in free radical polymerizations with quinoline-based monomers such as 6-vinylphenyl-(2-pyridinyl)-4-phenyl-quinoline (vinyl-QPy), and 6-vinylphenyl-(2-perfluorophenyl)-4-phenyl quinoline (vinyl-5FQ). The co-polymeric materials bearing the vinyl-QPy moiety were developed as potential compatibilizers in polymer electron donor–fullerene acceptor blends for non-covalent interactions with the fullerene part. The co-polymeric materials bearing the vinyl-5FQ moiety were developed for the covalent attachment of carbon nanostructures; specifically, PC61BM. Both copolymers and hybrids, after thorough purification, were characterized in terms of their spectroscopic and optical properties as well as their ability to form nanophased separated films as such, or as additives at various percentages into PCDTBT: PC71BM blends.

Second-order nonlinear optical properties of eight-membered centrosymmetric cyclic borasiloxanes

2019 ◽  
Vol 43 (27) ◽  
pp. 10948-10958
Author(s):  
Mohan Gopalakrishnan ◽  
Thamodharan Viswanathan ◽  
Ezhumalai David ◽  
Krishnan Thirumoorthy ◽  
Nattamai S. P. Bhuvanesh ◽  
...  
Keyword(s):  
Optical Properties ◽  
Silicon Atom ◽  
Nonlinear Optical ◽  
Crystal Packing ◽  
Second Order ◽  
Nonlinear Optical Properties ◽  
Strong Electron ◽  
Non Covalent Interactions ◽  
Electron Withdrawing Group ◽  
Covalent Interactions

SHG efficiencies of eight-membered centrosymmetric cyclic borasiloxanes arise form distorted silicon atom, strong electron withdrawing group and non-covalent interactions in crystal packing.

Nitrogen as a pnicogen?: Evidence for π-hole driven novel N…N interaction in nitromethane-ammonia dimers using matrix isolation infrared spectroscopy and ab initio computations

2021 ◽  
Author(s):  
Swaroop Chandra ◽  
B. Suryaprasad ◽  
Nagarajan Ramanathan ◽  
Sundararajan Kalyanasundaram
Keyword(s):  
Infrared Spectroscopy ◽  
Ab Initio ◽  
Electron Donor ◽  
Matrix Isolation ◽  
Non Covalent Interactions ◽  
Ab Initio Computations ◽  
Covalent Interactions

The role of nitrogen, the first member of pnicogen group, as an electron donor in hypervalent non-covalent interactions, has been established long ago, while observation of its electron accepting capability...

SUPPRESSION OF CHROMOPHORE AGGREGATION IN AMORPHOUS POLYMERIC MATERIALS: TOWARDS MORE EFFICIENT PHOTORESPONSIVE BEHAVIOR

2010 ◽  
Vol 19 (01) ◽  
pp. 57-73 ◽  
Author(s):  
ARRI PRIIMAGI ◽  
MATTI KAIVOLA ◽  
MATTI VIRKKI ◽  
FRANCISCO J. RODRÍGUEZ ◽  
MARTTI KAURANEN
Keyword(s):  
Phase Separation ◽  
System Performance ◽  
Polymeric Materials ◽  
Optical Performance ◽  
Polymer Backbone ◽  
Wide Range ◽  
Non Covalent Interactions ◽  
Optical Phenomena ◽  
Potential Impact ◽  
Covalent Interactions

We give an overview of our recent work on improving the optical performance of polymeric materials via supramolecular concepts, i.e., by making use of spontaneous non-covalent interactions between the chromophores and the polymer backbone. More precisely, we show that the aggregation of dipolar chromophores in amorphous polymeric materials can be controlled by simply choosing a proper polymer matrix. This approach has a potential impact in a wide range of optical phenomena where chromophore aggregation or phase separation sets a limit to the system performance.

Binding Studies on Resins Imprinted with (S)-naproxen

2002 ◽  
Vol 723 ◽  
Author(s):  
Yue Hu ◽  
Robert A. Orwoll
Keyword(s):  
Free Radical ◽  
Binding Sites ◽  
Affinity Binding ◽  
Binding Parameters ◽  
Glycol Dimethacrylate ◽  
Binding Studies ◽  
Number Of Binding Sites ◽  
Scatchard Equation ◽  
Non Covalent Interactions ◽  
Covalent Interactions

AbstractResins were prepared in a free-radical polymerization of 4-vinylpyridine and ethylene glycol dimethacrylate in the presence of (S)-(+)-6-methoxy-α-methyl-2-naphtaleneacetic acid ((S)-naproxen). Initially (S)-naproxen, the imprinted molecule template, was assembled with the monomer 4-vinylpyridine by non-covalent interactions. After the polymerization, stepwise removal of the template left binding sites that retain complementary specificity and affinity. Binding parameters including the maximum number of binding sites and dissociation constant were calculated from the amount of template removed using a two-site Scatchard equation. The results are typical of other systems reported in the literature.

Self-healing and shape-memory properties of polymeric materials cross-linked by hydrogen bonding and metal–ligand interactions

2019 ◽  
Vol 10 (33) ◽  
pp. 4519-4523 ◽  
Author(s):  
Yuichiro Kobayashi ◽  
Tomohiro Hirase ◽  
Yoshinori Takashima ◽  
Akira Harada ◽  
Hiroyasu Yamaguchi
Keyword(s):  
Hydrogen Bonding ◽  
Shape Memory ◽  
Polymeric Materials ◽  
Cross Linking ◽  
Self Healing ◽  
Shape Memory Properties ◽  
Ligand Interactions ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Metal Ligand

Polymeric materials were prepared by cross-linking them with two independent non-covalent interactions, namely hydrogen bonding and metal–ligand interactions.

scholarly journals NEDD8 Deamidation Inhibits Cullin RING Ligase Dynamics

2021 ◽  
Vol 12 ◽  
Author(s):  
Priyesh Mohanty ◽  
Kiran Sankar Chatterjee ◽  
Ranabir Das
Keyword(s):  
Conformational Changes ◽  
Salt Bridge ◽  
Md Simulations ◽  
Enteric Bacteria ◽  
Covalent Attachment ◽  
E3 Ligases ◽  
Ring E3 Ligase ◽  
Non Covalent Interactions ◽  
Ring E3 ◽  
Covalent Interactions

Cullin-RING ligases (CRLs) are a significant subset of Ubiquitin E3 ligases that regulate multiple cellular substrates involved in innate immunity, cytoskeleton modeling, and cell cycle. The glutamine deamidase Cycle inhibitory factor (Cif) from enteric bacteria inactivates CRLs to modulate these processes in the host cell. The covalent attachment of a Ubiquitin-like protein NEDD8 catalytically activates CRLs by driving conformational changes in the Cullin C-terminal domain (CTD). NEDDylation results in a shift from a compact to an open CTD conformation through non-covalent interactions between NEDD8 and the WHB subdomain of CTD, eliminating the latter’s inhibitory interactions with the RING E3 ligase-Rbx1/2. It is unknown whether the non-covalent interactions are sufficient to stabilize Cullin CTD’s catalytic conformation. We studied the dynamics of Cullin-CTD in the presence and absence of NEDD8 using atomistic molecular dynamics (MD) simulations. We uncovered that NEDD8 engages in non-covalent interactions with 4HB/αβ subdomains in Cullin-CTD to promote open conformations. Cif deamidates glutamine 40 in NEDD8 to inhibit the conformational change in CRLs by an unknown mechanism. We investigated the effect of glutamine deamidation on NEDD8 and its interaction with the WHB subdomain post-NEDDylation using MD simulations and NMR spectroscopy. Our results suggest that deamidation creates a new intramolecular salt bridge in NEDD8 to destabilize the NEDD8/WHB complex and reduce CRL activity.

Synthesis and electro-optical properties of carbazole derivatives with high band gap energy

2009 ◽  
Vol 518 (1) ◽  
pp. 284-289 ◽  
Author(s):  
Ki-Soo Kim ◽  
Seonju Jeong ◽  
Cham Kim ◽  
Younghwan Kwon ◽  
Byeong-Dae Choi ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Carbazole Derivatives ◽  
High Band

Modification of optical properties of PC-PBT/Cr2O3 and PC-PBT/CdS nanocomposites by gamma irradiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20402
Author(s):  
Kaoutar Benthami ◽  
Mai ME. Barakat ◽  
Samir A. Nouh
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Color Difference ◽  
Band Gap Energy ◽  
Polybutylene Terephthalate ◽  
Γ Irradiation ◽  
Gap Energy ◽  
Vis Spectroscopy ◽  
Oxygen Atoms

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells.

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