scholarly journals Synthesis and properties of 5,10,15,20-tetra[4-(3,5-dioctoxybenzamidephenyl] porphyrin and its metal complexes

2012 ◽  
Vol 77 (3) ◽  
pp. 335-348 ◽  
Author(s):  
Wenhui Lian ◽  
Yuanyuan Sun ◽  
Binbin Wang ◽  
Ning Shan ◽  
Tongshun Shi
Keyword(s):  
Metal Complexes ◽  
Raman Spectra ◽  
Metal Ion ◽  
Spectroscopic Properties ◽  
Molecular Structures ◽  
Photoelectron Spectra ◽  
Quantum Yields ◽  
Xps Spectra ◽  
Fluorescence Quantum Yields ◽  
Porphyrin Ligand

A novel 5,10,15,20-tetra[4-(3,5-dioctoxybenzamide)phenyl]porphyrin and its transition metal complexes are reported in this paper. Their molecular structures were characterized by elemental analysis, IR spectra, 1HNMR spectra and UV-Vis spectra. Their spectroscopic properties were studied by Raman spectra, fluorescence spectra and X-ray photoelectron spectra (XPS). The fluorescence quantum yields have been measured at room temperature. The fluorescence intensity of porphyrin ligand was stronger than that of the complexes. In Raman spectra, there was much difference between porphyrin ligand and its metal complexes due to changes of the symmetry of porphyrin plane. In the XPS spectra, the replacement of the free-base protons by a metal ion to form the metalloporphyrin increases the symmetry of the molecule also introduces an electron with-drawing group into the center of the porphyrin ligand which increases the N1s binding energy.

scholarly journals Synthesis and Spectral Analysis of Some Metal Ions Complexes with Mixed Ligands of Schiff Base and 1, 10-Phenanthroline

2017 ◽  
Vol 14 (1) ◽  
pp. 135-147
Author(s):  
Baghdad Science Journal
Keyword(s):  
Schiff Base ◽  
Metal Ions ◽  
Metal Complexes ◽  
Mass Spectrometer ◽  
Schiff Base Ligand ◽  
Metal Ion ◽  
Molecular Structures ◽  
Spectroscopic Techniques ◽  
Metal Ion Complexes ◽  
Free Schiff Base

The free Schiff base ligand (HL1) is prepared by being mixed with the co-ligand 1, 10-phenanthroline (L2). The product then is reacted with metal ions: (Cr+3, Fe+3, Co+2, Ni+2, Cu+2 and Cd+2) to get new metal ion complexes. The ligand is prepared and its metal ion complexes are characterized by physic-chemical spectroscopic techniques such as: FT-IR, UV-Vis, spectra, mass spectrometer, molar conductivity, magnetic moment, metal content, chloride content and microanalysis (C.H.N) techniques. The results show the formation of the free Schiff base ligand (HL1). The fragments of the prepared free Schiff base ligand are identified by the mass spectrometer technique. All the analysis of ligand and its metal complexes are in good agreement with the theoretical values indicating the purity of Schiff base ligand and the metal complexes. From the above data, the molecular structures for all the metal complexes are proposed to be octahedral

scholarly journals Synthesis, characterization and spectroscopic properties of some 2-substituted 1,3-indandiones and their metal complexes

2009 ◽  
Vol 7 (3) ◽  
pp. 429-438 ◽  
Author(s):  
Anife Ahmedova ◽  
Vasil Atanasov ◽  
Petja Marinova ◽  
Neyko Stoyanov ◽  
Mariana Mitewa
Keyword(s):  
Metal Complexes ◽  
Optical Sensors ◽  
Metal Ion ◽  
Spectroscopic Properties ◽  
Mass Spectral Fragmentation ◽  
Enolic Form ◽  
1H And 13C Nmr ◽  
Mass Spectral ◽  
Elemental Analyses ◽  
Ft Ir

AbstractNew 2-acyl-1,3-indandione derivatives, compounds 1–4, were obtained by condensation of 2-acetyl-1,3-indandione with benzaldehyde, thiophene-2-aldehyde, thiophene-3-aldehyde and furane-2-aldehyde, respectively. The structures of the newly synthesized 2-substituted 1,3-indandiones were characterized by means of spectroscopic methods (FT-IR, 1H and 13C NMR, UV-Vis and MS). Based on the obtained results it is suggested that the compounds exist in the exocyclic enolic form. Mass spectral fragmentation paths are also proposed. In order to verify the possibility for tautomerization processes of the newly synthesized compounds their absorption spectra were recorded in various solvents. Furthermore, the complexation properties of the compounds with metal(II) ions were also studied. A series of non-charged complexes with Cu(II), Cd(II), Zn(II), Co(II) and Ni(II) was isolated and analyzed by elemental analyses and IR. The paramagnetic Cu(II) complexes were studied by EPR and distorted, flattened tetrahedral structures are predicted. The other metal complexes show the presence of water molecules, most probably coordinated to the metal ion, thus forming octahedral geometry. Ultimately, the studied properties of the newly synthesized compounds, 1–4, suggest that they may find application as extracting agents for metal ions, rather than as optical sensors.

scholarly journals Theoretical and Experimental Investigations of Large Stokes Shift Fluorophores Based on a Quinoline Scaffold

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2488
Author(s):  
Barbara Czaplińska ◽  
Katarzyna Malarz ◽  
Anna Mrozek-Wilczkiewicz ◽  
Aneta Slodek ◽  
Mateusz Korzec ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Stokes Shift ◽  
Visible Region ◽  
Spectroscopic Properties ◽  
Cellular Membrane ◽  
Structural Features ◽  
Quantum Yields ◽  
Experimental Investigations ◽  
Case Scenario ◽  
Fluorescence Quantum Yields

A series of novel styrylquinolines with the benzylidene imine moiety were synthesized and spectroscopically characterized for their applicability in cellular staining. The spectroscopic study revealed absorption in the ultraviolet–visible region (360–380 nm) and emission that covered the blue-green range of the light (above 500 nm). The fluorescence quantum yields were also determined, which amounted to 0.079 in the best-case scenario. The structural features that are behind these values are also discussed. An analysis of the spectroscopic properties and the theoretical calculations indicated the charge-transfer character of an emission, which was additionally evaluated using the Lippert–Mataga equation. Changes in geometry in the ground and excited states, which had a significant influence on the emission process, are also discussed. Additionally, the capability of the newly synthesized compounds for cellular staining was also investigated. These small molecules could effectively penetrate through the cellular membrane. Analyses of the images that were obtained with several of the tested styrylquinolines indicated their accumulation in organelles such as the mitochondria and the endoplasmic reticulum.

Ground- and Excited-State Absorption Spectra of 9-Acetoxy-10(4´-Acetoxy)phenylanthracenes

1986 ◽  
Vol 41 (10) ◽  
pp. 1200-1209
Author(s):  
Janina R. Heldt
Keyword(s):  
Mirror Symmetry ◽  
Energy Levels ◽  
Bathochromic Shift ◽  
Heavy Atom ◽  
Excited State Absorption ◽  
Spectroscopic Properties ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Ring Molecules ◽  
Meso Position

The ground-(S0) and excited -(S1 and T1) state spectra of seven derivatives o f 9-acetoxy- 10(4´-acetoxy)phenylanthracene were determined in the region 50000 - 15000 cm -1 (200 - 660 nm). Comparison of these spectra to the unsubstituted molecule (anthracene) indicates the presence o f bathochromic shift and the steric effect. The substituents cause changes of positions of the energy levels (bigger shifts are noticed for low lying states) and also changes of the absorption intensities of some transitions. The steric hindrances between the phenyl-substituents and the anthracene skeleton are more pronounced if the - OAc(- Me) group or a heavy atom is introduced at position 2´o f the phenyl ring. Molecules possessing such substituents at the meso-position exhibit spectroscopic properties characteristic for a plane molecule in the S0 and S1 states; they show a better preservation of the mirror symmetry between the absorption and fluorescence spectra, lower Stokes shifts and the destabilization energies and bigger fluorescence quantum yields.

Vibrational dependence of electronic nonradiative processes in the state of and

1984 ◽  
Vol 62 (12) ◽  
pp. 1361-1368 ◽  
Author(s):  
D. Winkoun ◽  
D. Chapoulard ◽  
G. Dujardin ◽  
S. Leach
Keyword(s):  
Vibrational Mode ◽  
Spectroscopic Properties ◽  
Quantum Yields ◽  
Electronic Relaxation ◽  
Matrix Elements ◽  
Relaxation Rates ◽  
Fluorescence Quantum Yields ◽  
Fluorescence Photon ◽  
Mode Selectivity ◽  
Nonradiative Processes

Vibrational mode selective, radiationless transitions have been sought in the [Formula: see text] states of [Formula: see text] and [Formula: see text] by determining the radiative kr(ν′) and nonradiative knr(ν′) rates of electronic relaxation of energy selected vibronic levels of these cations. The relaxation rates were derived from measurements of ion fluorescence quantum yields and lifetimes using a photoelectron-fluorescence photon delayed coincidence apparatus, described in the text, in which the ions are formed by direct photoionization. Mode selective behavior is confirmed for the ν1 and ν2 modes of the [Formula: see text] state of [Formula: see text], previously studied by a threshold photoelectron-fluorescence photon coincidence method in which photoion formation involved auto-ionization as well as direct photoionization. In the case of the ν3 and ν4 modes of [Formula: see text], knr(ν′) was found to depend only on the excess energy Eν′ in the [Formula: see text] state and not on the particular mode optically excited. The absence of mode selectivity in this cation could be due to very rapid vibrational redistribution, but more probably results from similar-valued nonradiative coupling matrix elements of vibronic levels involving ν3 and (or) ν4 modes for a given value of Eν′. This is shown to be consistent with the known spectroscopic properties of [Formula: see text].

meso-(2-Benzimidazolyl)-substituted BODIPYs: Synthesis, structures and spectroscopic properties

2020 ◽  
Vol 24 (01n03) ◽  
pp. 230-237
Author(s):  
Hu Gao ◽  
Chenhong Li ◽  
Zhen Shen
Keyword(s):  
Quantum Yield ◽  
Spectroscopic Properties ◽  
Crystallographic Analysis ◽  
Membered Ring ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Nir Dyes ◽  
Nir Fluorescence ◽  
Yield Formula ◽  
Post Modification

A series of meso-(2-benzimidazolyl)-substituted boron dipyrromethene (BODIPY) derivatives 3a–3c and 4 have been synthesized and characterized. The absorption and fluorescence bands of 3a are bathochromically shifted by 36 nm and 61 nm, respectively, compared with those of the meso-phenyl BODIPY in toluene. More importantly, the fluorescence quantum yields of these meso-(2-benzimidazolyl)-substituted BODIPYs (up to 0.45 in toluene) are much higher than those of the previously reported meso-heterocyclic BODIPYs. X-ray crystallographic analysis of the single crystal structure of 3a revealed that the dihedral angle of meso-benzimidazolyl ring and indacene plane (40.47[Formula: see text] ) is smaller compared with that of the meso-tolyl substituted BODIPY (61.4[Formula: see text] ). Replacement of the six-membered ring with a five-membered ring, as well as the absence of hydrogen at the imino-nitrogen, generated the reduced repulsion and the hydrogen bonding interaction. The increased planarity not only provided the substantial delocalization of [Formula: see text] electrons and red shifted the absorption and emission bands but also enhanced the fluorescence quantum yield by reducing free rotation induced nonradiative deactivation pathway. Furthermore, 3,5-distyryl coupled BODIPY 4 exhibits a NIR fluorescence band at 712 nm with moderate quantum yield ([Formula: see text] [Formula: see text] 0.3) in nonpolar and polar solvents, which indicate that meso-(2-benzimidazolyl) BODIPY acts as a good candidate for post modification toward NIR dyes for biological applications.

scholarly journals The Effect of Varying Short-Chain Alkyl Substitution on the Molar Absorptivity and Quantum Yield of Cyanine Dyes

2011 ◽  
Vol 6 ◽  
pp. ACI.S6568 ◽  
Author(s):  
Gala Chapman ◽  
Maged Henary ◽  
Gabor Patonay
Keyword(s):  
Quantum Yield ◽  
Alkyl Chain ◽  
Cyanine Dyes ◽  
Spectroscopic Properties ◽  
Molar Absorptivity ◽  
Alkyl Chain Length ◽  
Short Chain ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Alkyl Substitution

The effect of varying short-chain alkyl substitution of the indole nitrogens on the spectroscopic properties of cyanine dyes was examined. Molar absorptivities and fluorescence quantum yields were determined for a set of pentamethine dyes and a set of heptamethine dyes for which the substitution of the indole nitrogen was varied. For both sets of dyes, increasing alkyl chain length resulted in no significant change in quantum yield or molar absorptivity. These results may be useful in designing new cyanine dyes for analytical applications and predicting their spectroscopic properties.

Influence of Internal Heavy Atoms on the Spectroscopic Properties of 9-Acetoxy-10-Phenylanthracene Derivatives

1984 ◽  
Vol 39 (10) ◽  
pp. 952-959 ◽  
Author(s):  
Janina R. Heidt
Keyword(s):  
Mirror Symmetry ◽  
Fluorescence Spectra ◽  
Spectroscopic Properties ◽  
Quantum Yields ◽  
Absorption And Fluorescence Spectra ◽  
Fluorescence Quantum Yields ◽  
Heavy Atoms ◽  
Decay Times ◽  
Anthracene Derivatives ◽  
Derivatives Of

Abstract Absorption and fluorescence spectra, fluorescence quantum yields and decay times have been measured for new derivatives of 9-acetoxy-10-acetoxyhalogenophenylanthracene in dioxane. It is found that the strength of the absorption transition decreases with increases atomic number Z of the halogen substituent whereas the strength of the fluorescence transition is constant with the exception for the fluoro-substituted derivatives. The loss of mirror symmetry between the absorption and fluorescence spectra is more evident for the 10-(4-acetoxy-3'-halogenophenyl)anthracene derivatives than for the remaining compounds. The determined nonradiative electronic relaxation rate constant and "dark reactions" quantum yield increases with increasing Z value. These findings are explained on the basis of the spin-orbit coupling enlarged by the heavy substituent and through perturbation of the functional groups, which causes different changes of the molecular geometries in the S0 and S*1 states, respectively.

scholarly journals Optical Characteristics and Applications of AIE Racemic C6-Unsubstituted Tetrahydropyrimidines

2021 ◽  
Vol 9 ◽  
Author(s):  
Qiuhua Zhu
Keyword(s):  
Optical Properties ◽  
Molecular Packing ◽  
Molecular Structures ◽  
Optical Characteristics ◽  
Quantum Yields ◽  
Central Ring ◽  
Strong Emission ◽  
Aryl Ring ◽  
Fluorescence Quantum Yields

Racemic C6-unsubstituted tetrahydropyrimidines (THPs) are the products of an efficient five-component reaction that we developed. THPs show strong AIE characteristics, that is, completely no fluorescence in different solvents but strong emission with fluorescence quantum yields (ΦF) up to 100% upon aggregation. However, the ΦF values of their pure enantiomers are lower than 46%. Unlike common AIE compounds with crowded aryl rotors on a π-bond or on an aryl ring, THPs have three completely non-crowded aryl rotors on a non-aromatic chiral central ring (tetrahydropyrimidine). In this mini review, we first discuss the AIE characteristics of THPs and the influences of molecular structures on their molecular packing modes and optical properties, and then present their applications and forecast the development of other racemic AIE compounds.

scholarly journals Synthesis, fluorescent studies, antioxidative and α-amylase inhibitory activity evaluation of some lanthanide(III) complexes

2018 ◽  
Vol 83 (5) ◽  
pp. 561-574 ◽  
Author(s):  
Surya Philip ◽  
Soosan Thomas ◽  
K. Mohanan
Keyword(s):  
Metal Complexes ◽  
Inhibitory Activity ◽  
Metal Ion ◽  
Antioxidant Property ◽  
Azomethine Nitrogen ◽  
Spectral Studies ◽  
Quantum Yields ◽  
Heterocyclic Ligand ◽  
Relative Quantum ◽  
Xrd Patterns

A novel heterocyclic ligand, viz. 1,2-dihydro-1,5-dimethyl-4-[[1-2- -oxo-2H-1-benzopyran-3-yl)ethylidene]amino]-2-phenyl-3H-pyrazol-3-one, was prepared by condensing 3-acetylcoumarin with 4-aminoantipyrine. This ligand is versatile in forming complexes with lanthanum(III), praseodymium(III), samarium(III), gadolinium(III) and dysprosium(III) ions. The ligand and the metal complexes were characterized through various physicochemical and spectral studies. The spectral studies revealed that the ligand is coordinated to the metal ion in a bidentate fashion, through the azomethine nitrogen and the oxygen atom of the pyrazolone ring. The powder XRD patterns of ligand and the dysprosium(III) complex were studied. The photoluminescent properties of ligand and metal complexes were evaluated and the relative quantum yields were determined. It was observed that in all cases the metal ions enhanced the luminescence intensity. The ?-amylase inhibitory activity of the ligand and the metal complexes was evaluated using the method of Apostolidis. The metal complexes exhibited increased activity compared to the ligand. The antioxidant property was also examined using the DPPH assay and the metal complexes were found to be more potent antioxidants than the ligand.

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