Synthesis of the most anti-aromatic 16π porphyrin: an octaethylporphyrin zinc(II) complex with no meso-substituents

2013 ◽  
Vol 17 (12) ◽  
pp. 1183-1187 ◽  
Author(s):  
Shogo Hiramatsu ◽  
Shun Sugawara ◽  
Satoshi Kojima ◽  
Yohsuke Yamamoto
Keyword(s):  
High Field ◽  
Blue Shift ◽  
The Novel ◽  
Porphyrin Ring ◽  
H Nmr ◽  
Field Shift ◽  
Significant Blue Shift ◽  
Unstable Species

The most anti-aromatic 16π porphyrin, an octaethylporphyrin (OEP) zinc(II) complex with no substituents at the meso-positions was generated as a highly unstable species from the reaction of the corresponding 18π porphyrin using strong oxidants such as AgSbF 6/ I 2 or SbF 5. The porphyrin showed a significant blue-shift unique to 16π porphyrins in its UV-vis spectrum. 1 H NMR measurements revealed an evident high-field shift of the meso-protons of the porphyrin ring, thereby establishing that the novel 16π porphyrin has the strongest anti-aromaticity reported so far.

Calcium-bis[N,N'-bis(trimethylsilyl)benzamidinat]-THF (1/2) - Synthese, spektroskopische Charakterisierung und Struktur/Calcium-bis[N,N'-bis(trimethylsilyl)benzamidinate]-THF (1/2) - Syntheses, Spectroscopic Characterization and Structure

1992 ◽  
Vol 47 (4) ◽  
pp. 453-459 ◽  
Author(s):  
Matthias Westerhausen ◽  
Wolfgang Schwarz
Keyword(s):  
Title Compound ◽  
High Field ◽  
Spectroscopic Characterization ◽  
Calcium Atom ◽  
Space Group ◽  
Bond Lengths ◽  
H Nmr ◽  
Distorted Octahedral ◽  
Anionic Charge ◽  
Field Shift

The reaction of calcium-bis[bis(trimethylsilyl)amide]-THF (1/2) with benzonitrile in THF nearly quantitatively yields the title compound calcium-bis[N,N'-bis(trimethylsilyl)- benzamidinate]-THF (1/2). Under similar conditions pivalonitrile substitutes an ether ligand of calcium-bis[bis(trimethylsilyl)amide]-DME (1/2) without the formation of the corresponding amidinate derivative. The calcium-di(benzamidinate) [H5C6-C(NSiMe3)2]2Ca · 2THF crystallizes in the space group Pbcn with {a = 188.8(6); b = 1286.0(3); c = 1802.5(5) pm; Z = 4}. The calcium atom is hexa-coordinate with a distorted octahedral trans-configuration and with Ca - O and Ca - N bond distances of 238 and 243 pm, respectively. The bond lengths within the NCN moiety with values of 132 pm are characteristic of a diazaallylic system. The short N - Si bond lengths of about 170.5 pm as well as the high field shift of the 29Si{1H} NMR signal are evidence for an effective backdonation of the anionic charge from the nitrogen to the silicon atoms.

scholarly journals Properties and Analysis of Transparency Conducting AZO Films by Using DC Power and RF Power Simultaneous Magnetron Sputtering

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Neng-Fu Shih ◽  
Jin-Zhou Chen ◽  
Yeu-Long Jiang
Keyword(s):  
Incident Light ◽  
Blue Shift ◽  
Light Wavelength ◽  
Rf Power ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dc Power ◽  
Incident Light Wavelength ◽  
Significant Blue Shift ◽  
Sputtering System

DC power and RF power were introduced into the magnetic controlled sputtering system simultaneously to deposit AZO films in order to get an acceptable deposition rate with high quality transparency conducting thin film. The resistivity decreases with the RF power for the as-deposited samples. The resistivity of 6 × 10−4 Ω-cm and 3.5–4.5 × 10−4 Ω-cm is obtained for the as-deposited sample, and for all annealed samples, respectively. The transmittance of the AZO films with higher substrate temperature is generally above 80% for the incident light wavelength within 400–800 nm. The transmittance of the as-deposited samples reveals a clear blue shift phenomenon. The AZO films present (002) oriented preference as can be seen from the X-ray diffraction curves. All AZO films reveal compressive stress. The annealing process improves the electrical property of AZO films. A significant blue shift phenomenon has been found, which may have a great application for electrode in solar cell.

scholarly journals Synthesis of Novel Compounds as New Potent Tyrosinase Inhibitors

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Hooshang Hamidian
Keyword(s):  
Kojic Acid ◽  
Azo Compounds ◽  
The Novel ◽  
Mushroom Tyrosinase ◽  
Reference Standard ◽  
Tyrosinase Inhibition ◽  
H Nmr ◽  
Ft Ir ◽  
Tyrosinase Inhibitors ◽  
C Nmr

In the present paper, we report the synthesis and pharmacological evaluation of a new series of azo compounds with different groups (1-naphthol, 2-naphthol, andN,N-dimethylaniline) and trifluoromethoxy and fluoro substituents in the scaffold. All synthesized compounds (5a–5f) showed the most potent mushroom tyrosinase inhibition (IC50values in the range of 4.39 ± 0.76–1.71 ± 0.49 µM), comparable to the kojic acid, as reference standard inhibitor. All the novel compounds were characterized by FT-IR,1H NMR,13C NMR, and elemental analysis.

Fluorinated s-Triazinyl Piperazines as Antimicrobial Agents

2011 ◽  
Vol 66 (7-8) ◽  
pp. 345-352 ◽  
Author(s):  
Rahul V. Patel ◽  
Premlata Kumari ◽  
Kishor H. Chikhalia
Keyword(s):  
Antimicrobial Agents ◽  
Inhibitory Concentration ◽  
Salmonella Typhi ◽  
The Novel ◽  
Proteus Vulgaris ◽  
Aspergillus Clavatus ◽  
H Nmr ◽  
Chemical Structures ◽  
Triazine Derivatives ◽  
C Nmr

A series of 1,3,5-triazine derivatives that contain 4-amino-2-trifl uoromethyl-benzonitrile, 8-hydroxyquinoline, and different piperazines as substituents at the carbon atoms of the triazine ring have been synthesized by a simple and efficient synthetic protocol. The chemical structures of the compounds were elucidated with the aid of IR, 1H NMR and 13C NMR spectroscopy, and elemental analysis. The antimicrobial activity of the compounds was tested against seven bacteria (Staphylococcus aureus MTCC 96, Bacillus cereus MTCC 619, Escherichia coli MTCC 739, Pseudomonas aeruginosa MTCC 741, Klebsiella pneumoniae MTCC 109, Salmonella typhi MTCC 733, Proteus vulgaris MTCC 1771) and four fungi (Aspergillus niger MTCC 282, Aspergillus fumigatus MTCC 343, Aspergillus clavatus MTCC 1323, Candida albicans MTCC 183). The results indicate that some of the novel s-triazines have noteworthy activity in minimum inhibitory concentration as well as agar diffusion tests.

Effect of Molecular Assembly on Photocycle of Reconstituted Bacteriorhodopsin: Significant Blue Shift of the Late M Photointermediate in the Liquid Crystalline Phase

2009 ◽  
Vol 38 (12) ◽  
pp. 1134-1135 ◽  
Author(s):  
Masashi Sonoyama ◽  
Takashi Kikukawa ◽  
Yasunori Yokoyama ◽  
Makoto Demura ◽  
Naoki Kamo ◽  
...  
Keyword(s):  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Blue Shift ◽  
Molecular Assembly ◽  
Liquid Crystalline Phase ◽  
Significant Blue Shift

Lyotropic liquid crystalline phthalocyanines containing 4-((S)-3,7-dimethyloctyloxy)phenoxy moieties

2017 ◽  
Vol 21 (01) ◽  
pp. 16-23 ◽  
Author(s):  
Sibel Eken Korkut ◽  
Hale Ocak ◽  
Belkıs Bilgin-Eran ◽  
Dilek Güzeller ◽  
M. Kasım Şener
Keyword(s):  
Liquid Crystalline ◽  
Spectroscopic Properties ◽  
The Novel ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
Wide Range ◽  
Ft Ir ◽  
Aggregation Behaviors ◽  
Mesomorphic Properties ◽  
Thermotropic Liquid Crystalline Behavior

The novel metal free phthalocyanine and its copper complex which are octa-substituted at the peripheral positions with 4-(([Formula: see text]-3,7-dimethlyoctyloxy)phenoxy moieties were synthesized and characterized by FT-IR, 1H NMR and mass spectroscopy. Their mesomorphic properties were studied by polarizing optical microscopy. The spectroscopic properties and aggregation behaviors of the novel phthalocyanines were also investigated by UV-vis spectroscopy in different solvents with same concentration as well as in a wide range of concentrations of chloroform. Both compounds with chloroform and [Formula: see text]-dodecane clearly show the lyotropic columnar mesophase in a wide temperature range whereas thermotropic liquid crystalline behavior for both compounds is not observed. Both of these novel compounds show no aggregation in toluene, tetrahydrofuran, dichloromethane and chloroform.

Metallkomplexe mit Tetrapyrrol-Liganden, LVI [1] / Metal Complexes with Tetrapyrrole Ligands, LVI [1]

1990 ◽  
Vol 45 (4) ◽  
pp. 531-542 ◽  
Author(s):  
Johann W. Buchler ◽  
Jürgen Löffler
Keyword(s):  
Cyclic Voltammetry ◽  
Metal Complexes ◽  
Mass Spectra ◽  
Electronic System ◽  
Porphyrin Ring ◽  
H Nmr ◽  
Double Decker ◽  
Porphyrin Rings

The reaction of tris(2,4-pentanedionato)europium(III) with a porphyrin H2(P)** in boiling 1,2,4-trichlorobenzene affords a so-called “redox mixture” of europium(III) bisporphyrinates, i. e. porphyrin π-radicals of the type Eu(P)2 and sandwiches EuH(P)2 in which one of the porphyrin rings is protonated. Thus, from either tetraphenylporphyrin or its dilithium derivative, or octaethylporphyrin, or a mixture of both porphyrins, the corresponding mixtures of double-deckers with two identical or two differnt porphyrin rings are obtained. The transformation of the redox mixtures into the pure tetraphenylporphyrin derivatives Eu(TPP)2, EuH(TPP)2, and the salt [NBu4] [Eu(TPP),, the separation of the octaethylporphyrin derivatives Eu(OEP)2 and EuH(OEP)2, and the purification of the “mixed” double-decker Eu(OEP)-(TPP) are described. The compounds are characterized by cyclic voltammetry, IR, UV/VIS/NIR, 1H NMR, and mass spectra. The obtained data indicate that the π-electrons of the two porphyrin rings behave as a common electronic system in which a defect electron is delocalized. However, in the “mixed” double-decker Eu(OEP) (TPP) the defect electron is more concentrated on the OEP ring, i. e. the porphyrin ring which is more easily oxidized.

Beiträge zur Chemie des Siliciums und Germaniums, XXXIX [1]. Darstellung, Eigenschaften und 29Si-NMR-Spektren von höheren Kaliumsilanylen KSinH2n+1 / Contributions to the Chemistry of Silicon and Germanium, XXXIX [1]. Preparation, Properties and 29Si-NMR Spectra of Higher Potassium Silanyls

1985 ◽  
Vol 40 (10) ◽  
pp. 1301-1305 ◽  
Author(s):  
Franz Fehér ◽  
Michael Krancher
Keyword(s):  
High Field ◽  
Nmr Spectra ◽  
The Other ◽  
29Si Nmr ◽  
Reaction Conditions ◽  
Low Field ◽  
Field Shift ◽  
29Si Nmr Spectra ◽  
Silicon And Germanium

Diluted solutions of potassium disilanyl, 2-potassium trisilanyl and 2-potassium isotetrasilanyl in m onoglym e have been prepared from potassium silyl and di- or trisilane under suitable reaction conditions. The purity of the silanyls varies between 95 and 99%. Their stability increases from potassium di- to 2-potassium isotetrasilanyl. The 29Si NMR spectra exhibit a strong high field shift for the metal substituted silicon atoms and a m oderate low field shift for the other silicon atoms compared with the signals of the corresponding silanes.

Preparation and properties of propargyl ether-terminated poly(imide siloxane)s and their composites

2020 ◽  
pp. 095400832095452
Author(s):  
Qing Ye ◽  
Qiaolong Yuan ◽  
Farong Huang
Keyword(s):  
Flexural Strength ◽  
Thermomechanical Analysis ◽  
Proton Nuclear Magnetic Resonance ◽  
Aromatic Diamine ◽  
The Novel ◽  
H Nmr ◽  
Chemical Structures ◽  
Propargyl Ether ◽  
Poly Imide ◽  
Thermal Stability Of

The novel propargyl ether-terminated oligo(imide siloxane)s (PTISs) based on 2,2’-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), aminopropyl-terminated polydimethylsiloxane (APPS), 4,4’-diaminodiphenylmethane (MDA) and p-aminophenyl propargyl ether (APPE) were synthesized. The chemical structures of PTISs were characterized by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FTIR). The PTISs exhibited excellent solubility in organic solvent and had broad processing window. The T300 carbon fabric was used to reinforce the PTIS matrices and prepare the composites (T300CF/PTISs). The thermal stability of the cured PTISs was analyzed by thermogravimetric analysis (TGA). The dynamic thermal mechanical properties of the composites were measured by dynamic thermomechanical analysis (DMA). The results show that the temperature at 5% weight loss (Td5) and residual yield at 800°C (Yr800°C) of the cured PTISs in N2 increase with incorporation of the aromatic diamine, whereas the Yr800°C of the cured PTISs in air decreases with introduction of the aromatic diamine. The elasticity of the composite increases with incorporation of the aromatic diamine, and the peak temperature of loss factor for the composites are higher than 300°C. The flexural strength, tensile strength and interlaminar layer shear strength (ILSS) of the T300CF/PTIS composite display the values of 439 MPa, 427 MPa and 32 MPa at room temperature, respectively. The retention of the flexural strength and ILSS for the T300CF/PTIS composite are above 80% at 250°C.

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