Tetra-2,3-pyrazinoporphyrazines with Externally Appended Thienyl Rings: Synthesis, UV–Visible Spectra, Electrochemical Behavior, and Photoactivity for the Generation of Singlet Oxygen

2011 ◽  
Vol 50 (17) ◽  
pp. 8225-8237 ◽  
Author(s):  
Giorgia De Mori ◽  
Zhen Fu ◽  
Elisa Viola ◽  
Xiaohui Cai ◽  
Claudio Ercolani ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Electrochemical Behavior ◽  
Visible Spectra ◽  
Uv Visible

Tetra-2,3-pyrazinoporphyrazines with externally appended pyridine rings 14: UV-visible spectral and electrochemical behavior of homo/heterobinuclear neutral and hexacationic macrocycles

2013 ◽  
Vol 17 (08n09) ◽  
pp. 896-904 ◽  
Author(s):  
Maria Pia Donzello ◽  
Daniela Vittori ◽  
David Futur ◽  
Zhen Fu ◽  
Claudio Ercolani ◽  
...  
Keyword(s):  
Electrochemical Behavior ◽  
Bathochromic Shift ◽  
Electronic System ◽  
Spectral Changes ◽  
Electronic Distribution ◽  
Low Concentrations ◽  
Half Wave ◽  
Visible Spectra ◽  
Uv Visible

Detailed UV-visible, electrochemical and spectroelectrochemical studies were carried out in DMSO on two known series of homo/heterobimetallic pyrazinoporphyrazine compounds, i.e.[( M′Cl 2) LM ] and [( PtCl 2)( CH 3)6 LM ]( I )6, where L = tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazinato anion, M = Zn II , Mg II ( H 2 O ) or Pd II and M′ = Pd II or Pt II . The [( M′Cl 2) LM ] compounds, as obtained from the mononuclear species [LM], undergo only subtle UV-visible spectral changes and exhibit practically unchanged half wave potentials for reduction; thus, peripheral coordination to the [LM] macrocycles of a single PdCl 2 or PtCl 2 unit at one of the external dipyridinopyrazine fragments only minimally disturbs the σ/π electronic distribution within the entire porphyrazine unit. In contrast, quaternization by CH 3 I of the six unligated pyridine N atoms of the species [( PtCl 2) LM ] leading to formation of the hexacations [( PtCl 2)( CH 3)6 LM ]6+ results in a significant bathochromic shift (5–15 nm) of the Q-band positions, thus suggesting an enhanced electron-withdrawing effect determined by an incremented displacement of the σ/π electronic system towards the periphery of the macrocycle. Accordingly, there is a facilitated thermodynamic uptake of electrons upon going from [( PtCl 2)( CH 3)6 LM ]6+ to [( PtCl 2)( CH 3)6 LM ] n (n = 5+ → 2+). Noteworthy, the UV-visible spectra of the salt-like species [( PtCl 2)( CH 3)6 LM ]( I )6 in water at c = 5 × 10-5 M ) indicate the presence of a monomer-dimer equilibrium, persistent even at very low concentrations (ca. 5 × 10-7 M).

Infrared and UV-visible spectra of layer semiconductors Gas, GaSe and GaTe

1977 ◽  
Vol 38 (10) ◽  
pp. 1293-1299 ◽  
Author(s):  
U. Giorgianni ◽  
G. Mondio ◽  
P. Perillo ◽  
G. Saitta ◽  
G. Vermiglio
Keyword(s):  
Visible Spectra ◽  
Uv Visible

Effect of NO2 substitution and solvent on UV-visible spectra, redox potentials and electron transfer mechanisms of copper β-nitrotriarylcorroles. Proposed electrogeneration of a Cu(I) oxidation state

2016 ◽  
Vol 20 (07) ◽  
pp. 753-765 ◽  
Author(s):  
Lina Ye ◽  
Zhongping Ou ◽  
Yuanyuan Fang ◽  
Yang Song ◽  
Bihong Li ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Soret Band ◽  
Redox Potentials ◽  
Nonaqueous Media ◽  
Initial Assignment ◽  
Visible Spectra ◽  
Phenyl Rings ◽  
Uv Visible ◽  
Electron Reduction ◽  
Transfer Mechanisms

Three copper triarylcorroles containing a [Formula: see text]-pyrrole nitro substituent were synthesized and characterized as to their spectral and electrochemical properties in nonaqueous media. The examined compounds are represented as [Formula: see text]-NO2(YPh)3CorCu, where Cor is the trianion of a triphenylcorrole and Y is a Cl, H or CH3 substituent at the para-position of the three meso-phenyl rings of the compound. The data from absorption spectra, electrochemistry and thin-layer spectroelectrochemistry are consistent with an initial assignment of Cu[Formula: see text]-Cor[Formula: see text] in CH2Cl2, DMF and pyridine and electrogeneration of a formal Cu(II) corrole with an unreduced macrocycle, represented as Cu[Formula: see text]-Cor[Formula: see text], after the first one-electron reduction in these solvents. The doubly reduced [Formula: see text]-nitrocorrole has a sharp Soret band at 439 nm and a well-defined Q-band at 611 nm in CH2Cl2. Similar absorption spectra are seen for the three examined doubly reduced nitrocorroles in DMF and pyridine, suggesting formation of a Cu(I) species with an unreduced macrocycle which is represented as Cu[Formula: see text]-Cor[Formula: see text]. Changes in redox potentials and absorption spectra of the nitrocorroles are examined as a function of solvent and substituents on the meso-phenyl rings of the compounds and comparisons are made between spectral and electrochemical data of the newly synthesized corroles and that of structurally related tetraarylcorroles lacking a [Formula: see text]-nitro group.

scholarly journals Synthesis, Characterization, and Biological Studies of a Piperidinyl Appended Dipicolylamine Ligand and Its Rhenium Tricarbonyl Complex as Potential Therapeutic Agents for Human Breast Cancer

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Amali Subasinghe ◽  
Inoka C. Perera ◽  
Svetlana Pakhomova ◽  
Theshini Perera
Keyword(s):  
Breast Cancer ◽  
Anticancer Agents ◽  
Human Breast Cancer ◽  
Human Breast ◽  
Tricarbonyl Complex ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Biological Studies ◽  
Visible Spectra ◽  
Uv Visible

A novel ligand bearing a central piperidinyl sulfonamide group, N(SO2pip)dpa, and its corresponding Re tricarbonyl complex, [Re(CO)3(N(SO2pip)dpa)]+, have been synthesized in good yield. The methylene CH2signal seen as a singlet (4.54 ppm) in a1H NMR spectrum of the ligand in DMSO-d6appears as two doublets (5.39, 5.01 ppm) in a spectrum of the [Re(CO)3(N(SO2pip)dpa)]+complex and confirms the presence of magnetically nonequivalent protons upon coordination to Re. Structural results revealed that the Re–N bond lengths fall within the normal range establishing coordination of ligand to metal. The presence of intraligandπ→π⁎andn→π⁎transitions is indicated by the absorption peaks around 200–250 nm in UV-visible spectra. Absorption peaks in UV-visible spectra around 300 nm for metal complexes were identified as MLCT transitions. The S–N stretch observed as a strong peak at 923 cm−1for N(SO2pip)dpa appeared at a shorter frequency, at 830 cm−1in an FTIR spectrum of the [Re(CO)3(N(SO2pip)dpa)]+. The intense fluorescence displayed by the N(SO2pip)dpa ligand has quenched upon coordination to Re. Relatively low IC50values given by human breast cancer cells, MCF-7, (N(SO2pip)dpa = 139 μM, [Re(CO)3(N(SO2pip)dpa)]+= 360 μM) indicate that N(SO2pip)dpa and [Re(CO)3(N(SO2pip)dpa)]+are promising novel compounds that can be further investigated on their usage as potential anticancer agents.

scholarly journals X-Ray, IR, NMR, UV-visible spectra and DFT analysis of 5-aryloxy-(1H)-tetrazoles, structure, conformation and tautomerism

2014 ◽  
Vol 3 (2) ◽  
pp. 85-96 ◽  
Author(s):  
Nader Noroozi Pesyan ◽  
Sadeghali Bavafa ◽  
Mohammad Samim Enayati ◽  
Sajedin Hoseinpour ◽  
Narges Ostadhosseini ◽  
...  
Keyword(s):  
X Ray ◽  
Visible Spectra ◽  
Uv Visible

The use of derivatives and chemometrics to interrogate the UV–Visible spectra of gin samples to monitor changes related to storage

2020 ◽  
Vol 227 ◽  
pp. 117548
Author(s):  
Nivetha Govindaraj ◽  
Sheeana Gangadoo ◽  
Vi Khanh Truong ◽  
James Chapman ◽  
Harsharn Gill ◽  
...  
Keyword(s):  
Visible Spectra ◽  
Uv Visible

Experimental and Theoretical Study of the High-Temperature UV–Visible Spectra of Aqueous Hydroquinone and 1,4-Benzoquinone

2016 ◽  
Vol 120 (40) ◽  
pp. 10547-10552 ◽  
Author(s):  
Fereshteh Samiee ◽  
Federico N. Pedron ◽  
Dario A. Estrin ◽  
Liliana Trevani
Keyword(s):  
High Temperature ◽  
Theoretical Study ◽  
Visible Spectra ◽  
Uv Visible

scholarly journals Synthesis and Bioassay of Novel Quinozolins

2019 ◽  
Vol 17 (72) ◽  
pp. 129-138
Author(s):  
Yasmine Kadom. Al-Majedy
Keyword(s):  
Twist Angle ◽  
Antimicrobial Properties ◽  
Heat Of Formation ◽  
Gram Negative Bacteria ◽  
The Novel ◽  
Gram Positive Bacteria ◽  
Visible Spectra ◽  
Ft Ir ◽  
Uv Visible

Novel Quinozolins were synthesized in a good yield through convert lacton to lactam and study the biological activity of the synthesized compounds. Quinozolins were characterized by elemental analysis, FT-IR and UV/visible spectra. The novel Quinozolins have been tested in vitro against (gram positive bacteria Staphylococcus aureus and against other gram negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus vulgaris; in order to assess their antimicrobial properties. Moreover, charge, bond length, bond angle, twist angle, heat of formation and steric energy were calculated by using of the ChemOffice program. The study indicates that these Quinozolins have high activity against tested bacteria. Based on the reported results, it may be concluded that the coumarin act as synthons for synthesis of new Quinozolins derivatives through the replacement of oxygen atom by nitrogen atom.

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