111550-48-2Relevant articles and documents
A novel class of sugar-based ether-linked-dispirooxindolo-pyrrolidines/ pyrrolizidines through [3+2]-cycloaddition of azomethine ylides
Hemamalini, Arasappan,Nagarajan, Subbiah,Mohan Das, Thangamuthu
, p. 12 - 17 (2012)
An efficient one-pot synthesis of novel sugar based dispirooxindolo- pyrrolidines/pyrrolizidines has been accomplished by a [3+2]-cycloaddition. This method utilizes an azomethine ylide derived from isatin and sarcosine/l-proline, with an ether linked α-,β-unsaturated-β-C- glycosidic ketones as the dipolarophile. All these sugar-based heterocyclics were characterized by NMR (1H and 13C) and elemental analysis. Antimicrobial studies of sugar based dispiroheterocyclic compound 10 shows excellent activity against different microbes.
Aliphatic ditopic nitrile N-oxide crosslinker: Synthesis, chemical stability, and catalyst-free crosslinking reactions
Akae, Yosuke,Monjiyama, Shunsuke,Sogawa, Hiromitsu,Takata, Toshikazu,Wang, Chen-Gang
, (2021)
Nitrile N-oxides are useful reagents and crosslinkers for catalyst- and byproduct-free 1,3-dipolar cycloaddition reactions. The stability of nitrile N-oxides can be enhanced by introducing bulky substituents, whereas their reactivity decreases concomitantly. Herein, an isolatable aliphatic ditopic nitrile N-oxide was synthesized and applied to catalyst-free crosslinking of unsaturated bond-containing polymers. By decreasing the steric hindrance around the nitrile N-oxide moiety compared with a related crosslinker previously developed in our group, the operating temperature of the crosslinking reaction could be lowered. Efficient crosslinking of natural rubber (NR) was achieved at 40 °C in chloroform to give crosslinked NR without formation of byproducts. Furthermore, polyacrylonitrile and nitrile butadiene rubber can be used as the scaffolds for efficient catalyst- and solvent-free crosslinking reactions.
Color-Tunable Amphiphilic Segmented π-Conjugated Polymer Nano-Assemblies and Their Bioimaging in Cancer Cells
Narasimha, Karnati,Jayakannan, Manickam
, p. 4102 - 4114 (2016)
We report a unique color tunable amphiphilic segmented π-conjugated polymer design and their π-stack driven diverse self-assembled nanostructures and demonstrate their application as a new classes of aqueous luminescent nanoparticle probes for bioimaging in cervical and breast cancer cells. Oligo-phenylenevinylene (OPV) was employed as rigid luminescent π-core and oligo-ethyleneoxy chains were used as flexible spacers to construct new amphiphilic segmented π-conjugated polymers by Witting-Horner polymerization route. The rigidity of the π-core was varied using tricyclodecanemethyleneoxy, 2-ethylhexyloxy or methoxy pendants and appropriate π-core geometry was optimized to achieve maximum aromatic π-stacking interactions. Solvent-induced chain aggregation of the polymers exhibited a morphological transition from one-dimensional helical nanofibrous to three-dimensional spherical nanoassemblies in good/bad solvent combinations. This morphological transformation was accompanied by the fluorescence color change from blue-to-white-to-yellow. CIE color coordinates exhibited x = 0.25 and y = 0.32 for the white light followed by the collective emission from aggregated and isolated OPV chromophores. Electron and atomic microscopes, steady state photophysical studies, time-resolved fluorescent decay analysis, and dynamic light scattering method enabled us to establish the precise mechanism for the self-assembly of segmented OPV polymers. The polymers produced stable and luminescent aqueous nanoparticles of 200 nm diameter in water. Cytotoxicity studies in cervical and breast cancer cells revealed that these new aqueous luminescent polymer nanoparticles are highly biocompatible and nontoxic to cells up to 60 μg/mL. Cellular uptake studies by confocal microscope further exposed that these nanoparticles were internalized in the cancer cells and they were predominantly accumulated in the nucleus. The present investigation opens up new amphiphilic segmented π-conjugated polymer design for producing diverse supramolecular assemblies and also demonstrates their new application as biocompatible fluorescent nanoprobes for imaging in cancer cells.
Synthesis and spectral properties of new ethylene glycol bridged oxazol-5-ones: High Stokes’ shift fluorophores sensitive to solvent polarity
Ozturk Urut, Gulsiye,Bayramin, Dilek,Alp, Serap
, p. 109 - 115 (2017/10/05)
A set of new oxazol-5-one fluorophores incorporating ethylene glycol chains terminated with an aldehyde unit has been synthesized and characterized structurally. Two pairs of compounds can be distinguished according to the substitution on the oxazol-5-one moiety: one pair bears a tolyl unit and the other a nitrophenyl unit. The difference within the pairs is the length of the ethylene glycol chain. The evaluation of absorption and emission properties of the new oxazol-5-one derivatives was carried out in seven different solvents of varying polarity, which showed intense absorption maxima at 384–418 nm and emission maxima at 430–607 nm, respectively. The solvatofluorism study of 3a and 3c revealed that their emission wavelengths are very sensitive to solvent polarity and are red shifted in polar solvents. 3a and 3c fluorophores exhibited high Stokes shift values between 4158 and 7921 cm? 1.
MULTIFUNCTIONAL NITRILEOXIDE COMPOUND
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Paragraph 0426-0427, (2015/09/28)
The present invention provides a compound of the formula (I): wherein: R2 and R3 represent each independently a hydrogen atom or a hydrocarbon group;A represents an s-valent organic group; ands is an integer of 2-10. This nitrileoxid
π-Conjugated polymer-Eu3+ complexes: Versatile luminescent molecular probes for temperature sensing
Balamurugan,Reddy,Jayakannan
, p. 2256 - 2266 (2013/07/31)
We report π-conjugated polymer-Eu3+ ion complexes as new potential luminescent thermo-sensitive molecular probes. Carboxylic acid functionalized segmented π-conjugated polymers having oligophenylenevinylene (OPV) chromophores in the poly(ethyleneoxide) or polymethylene backbones were custom designed, synthesized and utilized as efficient photosensitizers for Eu3+ ions. These π-conjugated polymer-Eu3+ ion complexes were found to be thermo-sensitive and behaved as reversible 'turn-on' or 'turn-off' luminescent switches in solution and in solid state. Luminescent decay studies revealed that the red-emission from the Eu3+ ion excited state was highly sensitive to temperature which drove the functioning of optical switches. The decay rate constants followed a typical Arrhenius trend over a wide temperature range having similar activation energies. Both the nature as well as length of the segmented polymer chain that tied the OPV optical chromophores in the backbone determine the temperature range of the luminescent on-off process. The emission characteristics of the oligomer-Eu 3+ ion complex were found to be non-thermosensitive which emphasized the need for the segmented π-conjugated polymer ligand structure for the probes based on Eu3+ ion complexes. The present strategy opens up new concept and molecular design principles for π-conjugated polymer-lanthanide ion complexes as potential candidates for temperature sensitive luminescent molecular probes. The Royal Society of Chemistry 2013.
Studies on the synthesis of ether-, substituted alkyl-, or aryl-linked C-disaccharide derivatives
Nagarajan, Subbiah,Jeganathan Shanmugam,Mohan Das, Thangamuthu
experimental part, p. 722 - 727 (2011/06/19)
A series of ether-, substituted alkyl-, or aryl-linked disaccharide derivatives have been synthesized in relatively good yield and characterized using different spectral techniques including single-crystal X-ray diffraction (XRD). β-Anomeric forms of sugar moiety in these derivatives were identified from 1H NMR studies. The existence of inter- and intramolecular hydrogen bonding interactions were identified from single-crystal XRD studies.
Aza-crown macrocycles as chiral solvating agents for mandelic acid derivatives
Quinn, Thomas P.,Atwood, Philip D.,Tanski, Joseph M.,Moore, Tyler F.,Folmer-Andersen, J. Frantz
experimental part, p. 10020 - 10030 (2012/02/05)
A series of new chiral macrocycles containing the trans-1,2- diaminocyclohexane (DACH) subunit and arene-and oligoethylene glycol-derived spacers has been prepared in enantiomerically pure form. Four of the macrocycles have been characterized by X-ray crystallography, which reveals a consistent mode of intramolecular N-H···N hydrogen bonding and conformational variations about the N-benzylic bonds. Most of the macrocycles were found to differentiate the enantiomers of mandelic acid (MA) by 1H NMR spectroscopy in CDCl3; within the series of macrocycles tested, enantiodiscrimination was promoted by (i) a meta-linkage geometry about the arene spacer, (ii) the presence of naphthalene-rather than phenylene-derived arene spacers, and (iii) increasing length of the oligoethylene glycol bridge. 1H NMR titrations were performed with optically pure MA samples, and the data were fitted to a simultaneous 1:1 and 2:1 binding model, yielding estimates of 2:1 binding constants between some of the macrocycles and MA enantiomers. In several cases, NOESY spectra of the MA: macrocycle complexes show differential intramolecular correlations between protons adjacent to the amine and carboxylic acid groups of the macrocycles and MA enantiomers, respectively, thus demonstrating geometric differences between the diastereomeric intermolecular complexes. The three most effective macrocycles were employed as chiral solvating agents (CSAs) to determine the enantiomeric excess (ee) of 18 MA samples over a wide ee range and with very high accuracy (1% absolute error) (Figure presented).
The interesting DNA-binding properties of three novel dinuclear Ru(II) complexes with varied lengths of flexible bridges
Ju, Chuan-Chuan,Zhang, An-Guo,Yuan, Chui-Li,Zhao, Xiao-Long,Wang, Ke-Zhi
experimental part, p. 435 - 443 (2012/02/14)
Three binuclear Ru(II) complexes with two [Ru(bpy)2(pip)] 2+-based subunits {where bpy = 2,2′-bipyridine and pip = 2-phenylimidazo[4,5-f][1,10]phenanthroline} being linked by varied lengths of flexible bridges, were synthesized and characterized by 1H NMR, elemental analysis, UV-visible (UV-vis) and photoluminescence spectroscopy. The structures of the three complexes were optimized by density functional theory calculations. The interaction of the complexes with calf thymus DNA was investigated by UV-vis and luminescence titrations, steady-state emission quenching by [Fe(CN)6]4-, DNA competitive binding with ethidium bromide, DNA melting experiments, and viscosity measurements. The experimental results indicated that the three complexes bound to the DNA most probably in a threading intercalation binding mode with high DNA binding constant values three orders of magnitude greater than the DNA binding constant value reported for proven DNA intercalator, mononuclear counterpart [Ru(bpy)2(p-mopip)]2+ {p-mopip = 2-(4-methoxylphenyl) imidazo[4,5-f][1,10]phenanthroline}.
A Double plug-socket system capable of molecular keypad locks through controllable photooxidation
Jiang, Wei,Han, Min,Zhang, Heng-Yi,Zhang, Zhi-Jun,Liu, Yu
supporting information; experimental part, p. 9938 - 9945 (2010/04/05)
Two robust divalent complexes have been successfully constructed by using complementary rigid spacers (anthracene vs. 1,4,5,8-naphthalenediimide (NDI)) and two pairs of [24]crown-8 ethers and secondary dialkylammonium functionalities as binding motifs. It
