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

2010 ◽  
Vol 82 (4) ◽  
pp. 757-767 ◽  
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.

scholarly journals Synthesis and Optoelectronic Properties of Iptycene–Naphthazarin Dyes

Synlett ◽  
2018 ◽  
Vol 30 (01) ◽  
pp. 54-58 ◽  
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.

Synthesis and characterization of 2-aminobenzoimidazolate group 11 coordination polymers: A combined X-ray powder diffraction and 13CP MAS NMR study

2008 ◽  
Vol 11 (5) ◽  
pp. 502-505 ◽  
Author(s):  
G. Attilio Ardizzoia ◽  
Stefano Brenna ◽  
Fulvio Castelli ◽  
Simona Galli ◽  
Norberto Masciocchi ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Coordination Polymers ◽  
Mas Nmr ◽  
Synthesis And Characterization ◽  
X Ray ◽  
Nmr Study

Synthesis and characterization of novel azo-embedded N-confused tetraphenylporphyrin

2009 ◽  
Vol 13 (02) ◽  
pp. 215-222 ◽  
Author(s):  
Motoki Toganoh ◽  
Takayoshi Hihara ◽  
Kentaro Yonekura ◽  
Yuichi Ishikawa ◽  
Hiroyuki Furuta
Keyword(s):  
Absorption Spectrum ◽  
Effective Interaction ◽  
Coupling Reaction ◽  
Crystallographic Analysis ◽  
Synthesis And Characterization ◽  
X Ray ◽  
H Nmr ◽  
Cis Isomer ◽  
C Nmr

A unique class of azo porphyrin, 5,10,15,20-tetraphenyl-21-phenylazo-(2-aza-21-carbaporphyrin 1, in which an azophenyl group is embedded in N -confused porphyrin, was synthesized and characterized by 1 H NMR, 13 C NMR, UV-vis absorption, MS, and X-ray crystallographic analysis. Synthesis of 1 was achieved through a coupling reaction of 21-amino N -confused tetraphenylporphyrin with nitrosobenzene and subsequent deoxygenation of resulting azoxy derivative with a trioxo rhenium(VII) N -fused porphyrinato catalyst. The azo-conjugate molecule was exclusively obtained as a trans-isomer and no isomerization to the cis-isomer was observed under thermal or photoirradiation. The absorption spectrum of 1 shows a moderate red-shift due to the effective interaction between the porphyrinic π-system and the connecting azophenyl group. Upon protonation, this effect is essentially lost as a result of removing degeneracy of LUMO and LUMO+1.

Synthesis and characterization of (η5-C5Me5)W(NO)I2, a monomeric, formally 16-electron complex

1988 ◽  
Vol 66 (8) ◽  
pp. 2100-2103 ◽  
Author(s):  
Neil H. Dryden ◽  
Peter Legzdins ◽  
Frederick W. B. Einstein ◽  
Richard H. Jones
Keyword(s):  
Molecular Structure ◽  
Molecular Weight ◽  
Solid State ◽  
Single Crystal ◽  
Significant Degree ◽  
Crystallographic Analysis ◽  
Synthesis And Characterization ◽  
X Ray ◽  
Degree Of Association

The compound (η5-C5Me5)W(NO)I2 has been prepared by treating (η5-C5Me5)W(NO)(CO)2 with I2. A single crystal X-ray crystallographic analysis establishes that the formally 16-electron complex possesses a monomeric, three-legged piano stool molecular structure in the solid state. Solution molecular weight measurements also indicate no significant degree of association of the compound.

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

Synlett ◽  
2017 ◽  
Vol 28 (12) ◽  
pp. 1427-1431 ◽  
Author(s):  
Timothy Swager ◽  
Cagatay Dengiz
Keyword(s):  
Electronic Properties ◽  
Free Electron ◽  
Structural Changes ◽  
Electron Acceptors ◽  
Synthesis And Characterization ◽  
Nmr Analysis ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Pull Systems

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.

Synthesis and structure of 3,5-dimethylpyrazolyl iron and cobalt dinitrosyl dimers

1979 ◽  
Vol 57 (23) ◽  
pp. 3119-3125 ◽  
Author(s):  
Kenneth S. Chong ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Cobalt Complex ◽  
Cobalt Complexes ◽  
Iron Complex ◽  
Synthesis And Characterization ◽  
Monoclinic Space Group ◽  
Boat Conformation ◽  
Coordination Geometry ◽  
X Ray ◽  
Metal Atoms

The synthesis and characterization of two 3,5-dimethylpyrazolyl metal dinitrosyl dimers [(N2C5H7)M(NO)2]2 (where M = Fe or Co) are described and their X-ray crystal structures detailed. Both complexes crystallize in the monoclinic space group C2/c, a = 23.848(2), 23.722(4), b = 10.7775(7), 10.6888(6), c = 14.764(1), 14.712(2) Å, β = 117.366(6), 117.094(7)°, Z = 8 (for the iron and cobalt complexes respectively). The structure of the iron complex was solved by Patterson and Fourier syntheses. The cobalt complex is isomorphous with the iron analog. Both structures were refined by full-matrix least-squares procedures to R = 0.028 and 0.035 for 4251 and 3376 reflections with I ≥ 3σ(I) respectively. Both complexes adopt a boat conformation for the central M—(N—N)2—M ring and display significantly non-linear M—N—O groups. The coordination geometry about the metal atoms is distorted tetrahedral. Important molecular dimensions (distances corrected for libration) are: mean Fe—N(pyrazolyl), 2.009(5), mean Fe—NO, 1.696(2) Å, Fe—N—O, 158.5(3)–168.2(2)°, mean Co—N(pyrazolyl), 1.992(7), Co—NO, 1.646(3)–1.680(3) Å, and Co—N—O, 161.6(3)–173.5(3)°. The iron complex is paramagnetic with formally "17-electron" iron atoms. Both structures are compared with similar four-coordinate metal dinitrosyl compounds.

Synthesis and characterization of TiN / Ti / AISI 410 coatings

2018 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
S Chirino ◽  
Jaime Diaz ◽  
N Monteblanco ◽  
E Valderrama
Keyword(s):  
Synthesis And Characterization ◽  
Photoemission Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Columnar Grains ◽  
Tin Thin Films ◽  
Steel Aisi ◽  
Interacting Surfaces ◽  
Stainless Steel Aisi

The synthesis and characterization of Ti and TiN thin films of different thicknesses was carried out on a martensitic stainless steel AISI 410 substrate used for tool manufacturing. The mechanical parameters between the interacting surfaces such as thickness, adhesion and hardness were measured. By means of the scanning electron microscope (SEM) the superficial morphology of the Ti/TiN interface was observed, finding that the growth was of columnar grains and by means of EDAX the existence of titanium was verified.  Using X-ray diffraction (XRD) it was possible to observe the presence of residual stresses (~ -3.1 GPa) due to the different crystalline phases in the coating. Under X-ray photoemission spectroscopy (XPS) it was possible to observe the molecular chemical composition of the coating surface, being Ti-N, Ti-N-O and Ti-O the predominant ones.

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

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.

scholarly journals Synthesis and Characterization of Clay Polymer Nanocomposites of P(4VP-co-AAm) and Their Application for the Removal of Atrazine

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 721 ◽  
Author(s):  
Jorge A. Ramírez-Gómez ◽  
Javier Illescas ◽  
María del Carmen Díaz-Nava ◽  
Claudia Muro-Urista ◽  
Sonia Martínez-Gallegos ◽  
...  
Keyword(s):  
Polymer Nanocomposites ◽  
Nanocomposite Materials ◽  
Synthesis And Characterization ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
Numerous Species ◽  
X Ray ◽  
Different Types ◽  
Synthesized Materials

Atrazine (ATZ) is an herbicide which is applied to the soil, and its mechanism of action involves the inhibition of photosynthesis. One of its main functions is to control the appearance of weeds in crops, primarily in corn, sorghum, sugar cane, and wheat; however, it is very toxic for numerous species, including humans. Therefore, this work deals with the adsorption of ATZ from aqueous solutions using nanocomposite materials, synthesized with two different types of organo-modified clays. Those were obtained by the free radical polymerization of 4-vinylpyridine (4VP) and acrylamide (AAm) in different stoichiometric ratios, using tetrabutylphosphonium persulfate (TBPPS) as a radical initiator and N,N′-methylenebisacrylamide (BIS) as cross-linking agent. The structural, morphological, and textural characteristics of clays, copolymers, and nanocomposites were determined through different analytical and instrumental techniques, i.e., X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Adsorption kinetics experiments of ATZ were determined with the modified and synthesized materials, and the effect of the ratio between 4VP and AAm moieties on the removal capacities of the obtained nanocomposites was evaluated. Finally, from these sets of experiments, it was demonstrated that the synthesized nanocomposites with higher molar fractions of 4VP obtained the highest removal percentages of ATZ.

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