Homoconjugated and Spiro Push–Pull Systems: Cycloadditions of Naphtho- and Anthradiquinones with Electron-Rich Alkynes

We report the synthesis and characterization of three new classes of push–pull chromophores using [2+2]-cycloaddition reactions of electron-rich alkynes and electron-poor alkenes. Previous investigations have focused on the reactions of cyano-substituted electron acceptors. This study demonstrates that cyano-free electron acceptors, naphtho- and anthradiquinones, can also be used to access extended push–pull systems. The effects of the structural changes on the spectroscopic and electronic properties were investigated by UV/vis spectroscopy. Structures were confirmed by X-ray and NMR analysis in solution.

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Synthesis and Optoelectronic Properties of Iptycene–Naphthazarin Dyes

Synlett ◽

10.1055/s-0037-1611169 ◽

2018 ◽

Vol 30 (01) ◽

pp. 54-58 ◽

Cited By ~ 1

Author(s):

Timothy Swager ◽

Cagatay Dengiz ◽

You-Chi Wu

Keyword(s):

Single Crystal ◽

Electronic Properties ◽

Diels Alder ◽

Optoelectronic Properties ◽

Synthesis And Characterization ◽

Nmr Analysis ◽

X Ray ◽

Vis Spectroscopy

We report the synthesis and characterization of iptycene–naphthazarin dyes by using a sequential Diels–Alder approach. The tautomerization of naphthazarin was used as the key step in the synthesis, with structures confirmed by single-crystal X-ray and NMR analysis. The systematic trends in electronic properties were investigated by UV/Vis spectroscopy. BF2 complexes of the dyes were prepared by reaction with BF3·OEt2 in CH2Cl2.

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Synthesis and characterization of Fe, Co, and Ni colloids in 2-mercaptoethanol

Nanomaterials and Nanotechnology ◽

10.1177/1847980420966883 ◽

2020 ◽

Vol 10 ◽

pp. 184798042096688

Author(s):

Galo Cárdenas-Triviño ◽

Sergio Triviño-Matus

Keyword(s):

Electron Microscopy ◽

Electron Diffraction ◽

Colloidal Dispersions ◽

Synthesis And Characterization ◽

X Ray ◽

Transmission Electron ◽

Vis Spectroscopy ◽

Chemical Liquid Deposition ◽

Liquid Deposition

Metal colloids in 2-mercaptoethanol using nanoparticles (NPs) of iron (Fe), cobalt (Co), and nickel (Ni) were prepared by chemical liquid deposition method. Transmission electron microscopy, electron diffraction, UV-VIS spectroscopy, and scanning electron microscopy with electron dispersive X-ray spectroscopy characterized the resulting colloidal dispersions. The NPs exhibited sizes with ranges from 9.8 nm for Fe, 3.7 nm for Co, and 7.2 nm for Ni. The electron diffraction shows the presence of the metals in its elemental state Fe (0), Co (0), and Ni (0) and also some compounds FeO (OH), CoCo2S4, and NiNi2S4.

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CAAC Boranes. Synthesis and characterization of cyclic (alkyl) (amino) carbene borane complexes from BF3 and BH3

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.6.82 ◽

2010 ◽

Vol 6 ◽

pp. 709-712 ◽

Cited By ~ 16

Author(s):

Julien Monot ◽

Louis Fensterbank ◽

Max Malacria ◽

Emmanuel Lacôte ◽

Steven J Geib ◽

...

Keyword(s):

Silica Gel ◽

Synthesis And Characterization ◽

Gel Chromatography ◽

Nmr Analysis ◽

X Ray ◽

X Ray Crystallography ◽

In Situ Formation ◽

Silica Gel Chromatography

In situ formation of two cyclic (alkyl) (amino) carbenes (CAACs) followed by addition of BF3•Et2O provided the first two examples of CAAC–BF3 complexes: 1-(2,6-diisopropylphenyl)-3,5,5-trimethyl-3-phenylpyrrolidin-2-ylidene trifluoroborane, and 2-(2,6-diisopropylphenyl)-3,3-dimethyl-2-azaspiro[4.5]decan-1-ylidene trifluoroborane. These CAAC–BF3 complexes are robust compounds that are stable to ambient laboratory conditions and silica gel chromatography. They were characterized by spectroscopy and X-ray crystallography. In contrast, a CAAC complex with borane (BH3) was readily formed in situ according to 1H and 11B NMR analysis, but did not survive the workup conditions. These results set the stage for further studies of the chemistry of CAAC boranes.

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Synthesis and Characterization of Cyclic Silenolates

10.14293/p2199-8442.1.sop-chem.pkajzo.v1 ◽

2014 ◽

Author(s):

Michael Haas ◽

Roland Fischer ◽

Ana Torvisco ◽

Harald Stueger

Keyword(s):

Single Crystals ◽

Structure Analysis ◽

High Selectivity ◽

Ring Cleavage ◽

Synthesis And Characterization ◽

Nmr Analysis ◽

Subsequent Reaction ◽

X Ray ◽

Carbonyl Function

Based on earlier work by Ottosson [1] and Ohshita [2] the previously unknown cyclic silenolates 1a-c and 2a-b have been synthesized by the reaction of acylcyclohexasilanes with one or two equivalents of KOtBu. The nature of the anions (silenide or silenolate) and consequently the outcome of subsequent reaction steps largely depends on the substituent R at the carbonyl function. Detailed NMR-analysis of 1a-c and 2a-b corroborate this deduction. Furthermore, for 1a-c and 2a-b single crystals which were suitable for X-ray structure analysis could be grown. Very interesting is the reactivity of 1b, which at 50°C undergoes a hitherto unknown 1,4-trimethylsilyl-migration followed by a ring cleavage of the cyclohexasilane cycle to form the anion 3a. The high selectivity of these reactions is demonstrated by the formation of an acyl-functionalized bicyclo-2,2,2-octasilane in >90% yield from 2a and \(ClSiMe_{2}SiMe_{2}Cl\).

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Synthesis and Characterization of a Three-dimensional Porous Compound: [Cu(H2O)6][{Cu(H2O)2}2{Cu(H2O)4H4W12O42}] · 12H2O

Zeitschrift für Naturforschung B ◽

10.1515/znb-2008-0212 ◽

2008 ◽

Vol 63 (2) ◽

pp. 187-192 ◽

Cited By ~ 5

Author(s):

Chun-jing Zhang ◽

Ya-guang Chen ◽

Dong-mei Shi ◽

Hai-jun Pang

Keyword(s):

Aqueous Solution ◽

Magnetic Susceptibility ◽

Elemental Analysis ◽

3D Structure ◽

Three Dimensional ◽

Synthesis And Characterization ◽

X Ray Diffraction ◽

X Ray ◽

Vis Spectroscopy

A novel transition metal polyoxotungstate, [Cu(H2O)6][{Cu(H2O)2}2{Cu(H2O)4H4W12O42}] · 12H2O (1), has been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction, elemental analysis, IR and UV/vis spectroscopy, and TG analysis. The paradodecatungstate anions [H2W12O42]10− are linked by CuO6 octahedra, forming a three-dimensional (3D) structure. The magnetic susceptibility of compound 1 in the temperature range 2 - 300 K shows the presence of antiferromagnetic interactions within the uniform Cu2・・・Cu3 chains

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Synthesis and characterization of thermosensitive and polarity-sensitive fluorescent PNIPAM-coated gold nanoparticles

e-Polymers ◽

10.1515/epoly-2016-0247 ◽

2017 ◽

Vol 17 (1) ◽

pp. 65-70 ◽

Cited By ~ 1

Author(s):

Chunhua Luo ◽

Meijuan Qian ◽

Qiujing Dong

Keyword(s):

Photoelectron Spectroscopy ◽

Au Nanoparticles ◽

Synthesis And Characterization ◽

Strong Fluorescence ◽

X Ray ◽

Transmission Electron ◽

Vis Spectroscopy ◽

Grafting Through ◽

Polarity Sensitive

AbstractThermosensitive PNIPAM-coated Au nanoparticles (AuNPs@P(NIPAM-co-MADMAC)) were synthesized by the radical “grafting through” copolymerization of 4-methacryloyloxy-4′-dimethylaminochalcone (MADMAC), MAEL-capped AuNPs and N-isopropylacrylamide (NIPAM) using azobisisobutyronitrile (AIBN) as the initiator. AuNPs@P(NIPAM-co-MADMAC) were characterized by transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis) spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), 1H nuclear magnetic resonance (NMR), and Fourier transform infrared (FTIR) spectroscopy. AuNPs@P(NIPAM-co-MADMAC) exhibited thermo-sensitivity from poly(NIPAM-co-MADMAC) chains and sensitive fluorescence from the MADMAC group. AuNPs@P(NIPAM-co-MADMAC) showed weak fluorescence after the temperature increased from 25°C to 45°C, or after β-cyclodextrin (β-CD) was added. Furthermore, it exhibited strong fluorescence when the solvent was changed to ethanol or chloroform.

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In-depth understanding of π-electron systems: New vistas in fullerene endohedrals

Pure and Applied Chemistry ◽

10.1351/pac-con-09-08-18 ◽

2010 ◽

Vol 82 (4) ◽

pp. 757-767 ◽

Cited By ~ 12

Author(s):

Michio Yamada ◽

Takahiro Tsuchiya ◽

Takeshi Akasaka ◽

Shigeru Nagase

Keyword(s):

Electronic Properties ◽

Theoretical Calculations ◽

Crystallographic Analysis ◽

Synthesis And Characterization ◽

Electron Systems ◽

X Ray ◽

Endohedral Metallofullerenes ◽

Metal Atoms ◽

Nmr Study

The synthesis and characterization of various endohedral metallofullerenes and their derivatives are described. The encapsulated metal atoms’ positions and movements were determined using NMR study, X-ray crystallographic analysis, and theoretical calculations. The results of electrochemical investigations clarified the relation between the electronic properties and the π-electron systems of the fullerene endohedrals.

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Synthesis and Characterization of Ceramic Modified with Niobium for Biomedical Applications

Materials Science Forum ◽

10.4028/www.scientific.net/msf.869.884 ◽

2016 ◽

Vol 869 ◽

pp. 884-889

Author(s):

Nadia Sueli Vieira Capanema ◽

Alexandra A.P. Mansur ◽

Herman Sander Mansur

Keyword(s):

Biomedical Applications ◽

Room Temperature ◽

Structural Changes ◽

Calcium Phosphates ◽

Synthesis And Characterization ◽

Body Parts ◽

New Materials ◽

X Ray Diffraction ◽

X Ray

The need for obtaining new materials to replace human body parts that were destroyed or damaged led scientists from different areas of research for developing new biomaterials. Thus, the aim of this work was the synthesis and characterization of niobium-modified apatite bioceramics. Calcium phosphates (CaP) were synthesized with niobium partially replacing calcium sites using aqueous precipitation route at room temperature. The bioceramics, with and without Nb incorporation, were characterized by scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) as prepared and after heat treatments The results indicated that Nb was incorporated in the apatite structure promoting morphological and structural changes in the ceramic properties.

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Synthesis and characterization of Se-based nanoparticles as potential generators of reactive oxygen species

MRS Advances ◽

10.1557/adv.2019.137 ◽

2019 ◽

Vol 4 (07) ◽

pp. 419-424

Author(s):

Nadja Maldonado-Luna ◽

Sonia Bailón-Ruiz ◽

Myrna Reyes-Blas ◽

Oscar J. Perales-Perez

Keyword(s):

Reactive Oxygen Species ◽

Reactive Oxygen ◽

Synthesis And Characterization ◽

Oxygen Species ◽

Ongoing Research ◽

X Ray ◽

Microwave Assisted ◽

Transmission Electron ◽

Vis Spectroscopy

ABSTRACTThis work presents the synthesis of selenium-based nanoparticles via microwave-assisted heating and their subsequent characterization using UV-vis Spectroscopy (UV-Vis), high-resolution transmission electron microscopy (HRTEM), and energy-dispersive X-ray spectroscopy (EDX), techniques. Ongoing research includes the study of the nanoparticles capacity to generate reactive oxygen species (ROS).

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Synthesis and characterization of Cu-ZrB2 alloy produced by PM techniques

Science of Sintering ◽

10.2298/sos1402217r ◽

2014 ◽

Vol 46 (2) ◽

pp. 217-224 ◽

Cited By ~ 5

Author(s):

J. Ruzic ◽

J. Stasic ◽

S. Markovic ◽

K. Raic ◽

D. Bozic

Keyword(s):

Copper Alloy ◽

Strong Influence ◽

Structural Changes ◽

Milling Time ◽

Morphological Properties ◽

Synthesis And Characterization ◽

X Ray Diffraction ◽

X Ray ◽

Scanning Electron

The copper alloy with 7vol.% ZrB2 examined in this study was consolidated via powder metallurgy processing (PM) by combining mechanical alloying and hot pressing process. Structural changes, morphological properties and elemental analysis of the hotpressed samples were studied as a function of milling time with the use of X-ray diffraction, scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectrometry (EDS). Also, mechanical properties of the Cu-7vol.%ZrB2 alloy was investigated. Distribution of ZrB2 particles and presence of agglomerates in the Cu matrix directly depend on the milling time and show strong influence on hardness, compressive and electrical properties of Cu-ZrB2 alloys.

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