Synthesis and spectral evaluation of 5,10,15,20-tetrakis(3,4-dibenzyloxyphenyl)porphyrin

2017 ◽  
Vol 23 (2) ◽  
pp. 79-83
Author(s):  
Cynthia P. Tidwell ◽  
Prakash Bharara ◽  
Kenneth A. Belmore ◽  
Qiaoli Liang ◽  
Gregory W. Dye ◽  
...  
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Nuclear Overhauser Effect ◽  
Soret Band ◽  
Molar Absorptivity ◽  
H Nmr ◽  
Maldi Tof ◽  
Overhauser Effect ◽  
Spectral Evaluation ◽  
Nuclear Overhauser ◽  
C Nmr

AbstractPorphyrins are of interest in many applications that involve electron transfer and absorption of light, such as solar energy and photodynamic cancer therapy. The newly synthesized 5,10,15,20-tetrakis(3,4-dibenzyloxyphenyl)porphyrin, TDBOPP, was characterized using 1H NMR, 13C NMR, UV-vis and fluorescence spectroscopy and MALDI-TOF/TOF high resolution mass spectrometry. Standard 1H NMR and 13C NMR experiments coupled with nuclear Overhauser effect (NOE) experiments confirmed the structure of the compound. The expected M+ and [M+H]+ ions are observed in the MALDI-TOF/TOF mass spectrum. The UV-vis absorption spectrum of TDBOPP shows a Soret band at 424 nm and three Q bands at 519 nm, 556 nm, and 650 nm with molar absorptivity 3.6×105 cm−1m−1, 1.6×104 cm−1m−1, 1.0×104 cm−1m−1 and 5.3×103 cm−1m−1, respectively. Excitation at 424 nm gives emission at 650 nm. The quantum yield of the porphyrin is 0.11.

Synthesis, stereochemistry, and transformations of (E)-1,2-bis(benzenesulfonyl)ethylene cycloadducts to 2-oxa substituted 1,3-dienes

1984 ◽  
Vol 62 (11) ◽  
pp. 2487-2497 ◽  
Author(s):  
Ottorino De Lucchi ◽  
Vittorio Lucchini ◽  
Moreno Zamai ◽  
Giorgio Modena ◽  
Giovanni Valle
Keyword(s):  
Nuclear Overhauser Effect ◽  
H Nmr ◽  
Overhauser Effect ◽  
Nuclear Overhauser ◽  
High Yields ◽  
Structure Assignment

The cycloaddition of (E)-1,2-bis(benzenesulfonyl)ethylene (2) to 2-acetoxy- and 2-silyloxy-1,3-cyclodienes occurs in high yields and with high steroselectivity. Structure assignment has been based largely on 1H nmr nuclear Overhauser effect (nOe) experiments on the isolated products. The cycloadducts 4a and 4b derived from the 2-oxa substituted cyclopentadienes have been further elaborated to the parent norbornenone, to the respective unsaturated sulfones 5, and to the β-hydroxy substituted sulfone 6. The vinyl sulfones 5 have also been independently synthesized via cycloaddition of benzenesulfonyl acetylene. The sulfones obtained are potentially important starting molecules for the preparation of more complex targets.

An evaluation of high resolution nuclear magnetic resonance experiments and protocols in the structure elucidation of organic molecules. I. A relatively simple system, brucine

1985 ◽  
Vol 63 (2) ◽  
pp. 483-490 ◽  
Author(s):  
Michael A. Bernstein ◽  
Laurance D. Hall
Keyword(s):  
High Resolution ◽  
Chemical Shift ◽  
Structural Information ◽  
Nuclear Overhauser Effect ◽  
Proton Spectrum ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Overhauser Effect ◽  
Nuclear Overhauser ◽  
Nmr Methods

Using a combination of one-dimensional (1D) and two-dimensional (2D) high resolution nmr methods, the 1H nmr spectrum of brucine was fully assigned. The 2D J-resolved and homonuclear chemical shift correlated (COSY) experiments provided assignments without full structural information; this was obtained from nuclear Overhauser effect (nOe) enhancement experiments (1D and 2D). With the proton spectrum fully assigned, proton-bearing carbons in the 13C nmr spectrum were easily assigned using the 2D heteronuclear chemical shift correlation map (CSCM) experiment.

The isolation and structural elucidation of a new iridoid glycoside from Cymbaria dahurica L.

2018 ◽  
Vol 73 (6) ◽  
pp. 377-379 ◽  
Author(s):  
Cui-Lan Bai ◽  
Qing-Hu Wang ◽  
Yan-Hua Xu ◽  
Jun-Sheng Han ◽  
Yin-Ping Bao
Keyword(s):  
Quantum Coherence ◽  
Nuclear Overhauser Effect ◽  
Multiple Bond ◽  
2D Nmr ◽  
Iridoid Glycoside ◽  
Correlation Spectroscopy ◽  
Etoac Extract ◽  
Overhauser Effect ◽  
Nuclear Overhauser ◽  
C Nmr

AbstractA new iridoid glycoside, namely, cymdahoside A (1), together with two known ones, 2 and 3, were isolated from the EtOAc extract of Cymbaria dahurica. The structure elucidation of 1 was carried out by one-dimensional (1D) NMR (1H and 13C NMR) and 2D NMR (correlation spectroscopy, heteronuclear single-quantum coherence, heteronuclear multiple-bond correlation and nuclear Overhauser effect spectroscopy) spectral analyses.

scholarly journals Changes in the Physicochemical Properties of Piperine/β-Cyclodextrin due to the Formation of Inclusion Complexes

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Toshinari Ezawa ◽  
Yutaka Inoue ◽  
Sujimon Tunvichien ◽  
Rina Suzuki ◽  
Ikuo Kanamoto
Keyword(s):  
Physicochemical Properties ◽  
Nuclear Overhauser Effect ◽  
Biological Activities ◽  
Black Pepper ◽  
Molar Ratio ◽  
Stoichiometric Ratio ◽  
H Nmr ◽  
Overhauser Effect ◽  
Methylene Groups ◽  
Nuclear Overhauser

Piperine (PP) is a pungent component in black pepper that possesses useful biological activities; however it is practically insoluble in water. The aim of the current study was to prepare a coground mixture (GM) of PP and β-cyclodextrin (βCD) (molar ratio of PP/βCD = 1/1) and subsequently evaluate the solubility of PP and physicochemical properties of the GM. DSC thermal behavior of the GM showed the absence of melting peak of piperine. PXRD profile of the GM exhibited halo pattern and no characteristic peaks due to PP and βCD were observed. Based on Job’s plot, the PP/βCD complex in solution had a stoichiometric ratio of 1/1. Raman spectrum of the GM revealed scattering peaks assigned for the benzene ring (C=C), the methylene groups (CH2), and ether groups (C-O-C) of PP that were broaden and shifted to lower frequencies. SEM micrographs showed that particles in the GM were agglomerated and had rough surface, unlike pure PP and pure βCD particles. At 15 min of dissolution testing, the amount dissolved of PP in the GM was dramatically increased (about 16 times) compared to that of pure PP. Moreover the interaction between PP and βCD cavity was detected by 1H-1H NMR nuclear Overhauser effect spectroscopy NMR spectroscopy.

Electronic excited states of small ring compounds. IV. Bicyclo[2.1.0]pentanes by the photocycloaddition of cyclopropenes to olefins

1977 ◽  
Vol 55 (3) ◽  
pp. 393-406 ◽  
Author(s):  
D. R. Arnold ◽  
R. M. Morchat
Keyword(s):  
Excited States ◽  
Nuclear Overhauser Effect ◽  
Dimethyl Fumarate ◽  
Small Ring ◽  
H Nmr ◽  
Ring Compounds ◽  
Overhauser Effect ◽  
Direct Irradiation ◽  
Nuclear Overhauser ◽  
Thermal Stability Of

Direct irradiation of the charge-transfer complex between the cyclopropenes 3,3-dimethyl-1,2-diphenylcyclopropene (3) and 1,2,3-triphenylcyclopropene (7), and the electron deficient olefins dimethyl fumarate (5) and maleic anhydride (11) resulted in formation of the cycloadducts 6, 12–15 which are the bicyclo[2.1.0]pentane derivatives. These products were also formed when the reaction was photosensitized by triplet–triplet transfer. The structure of the adducts rests largely upon the interpretation of 13C and 1H nmr spectra. Nuclear Overhauser effect studies were used to assign stereochemistry. The thermal stability of these new bicyclo[2.1.0]-pentane derivatives has been examined, particularly with regard to the ring-flipping process and the rearrangement to the corresponding cyclopentene derivatives.

Preparation and physicochemical characterization of inclusion complexes derived from phytosterols and β-cyclodextrin

2019 ◽  
Vol 16 (2) ◽  
pp. 145-159 ◽  
Author(s):  
Ana Lía Rossi ◽  
Eduardo Miguel Rustoy ◽  
Gabriel Cases ◽  
Adriana Mabel Rosso
Keyword(s):  
Inclusion Complexes ◽  
High Resolution Mass Spectrometry ◽  
Nuclear Overhauser Effect ◽  
Structural Characteristics ◽  
Physicochemical Characterization ◽  
Aqueous Solubility ◽  
Scanning Calorimetry ◽  
Guest Molecules ◽  
Overhauser Effect ◽  
Nuclear Overhauser

Phytosterols (PS), that is vegetable sterols, are compounds widely recognized for lowering the absorption of cholesterol and decreasing cancer risk, with βsitosterol, stigmasterol and campesterol being the most abundant. As PS is poorly soluble in aqueous solutions, many approaches have been proposed to increase their solubility and bioavailability. β-cyclodextrin (β-CD) could be used to increase PS aqueous solubility because of its capacity to entrap a variety of hydrophobic guest molecules in its cavity. In this work, the formation of β-CD/PS inclusion complexes was confirmed by Differential Scanning Calorimetry (DSC), Electrospray Ionization-High Resolution Mass Spectrometry (ESIHRMS) and Fourier Transform Infrared Spectroscopy (FT-IR), while structural characteristics were determined by one- and two-dimensional Nuclear Magnetic Resonance (NMR) techniques. Results confirmed 1:1 binding stoichiometry, which suggests the total inclusion of rings and chains of the different PS. The hypothesis of folding of the lateral chains into the cavity may be supported by the multiple correlations observed in the Nuclear Overhauser Effect Spectroscopy (NOESY) and rotatingframe Nuclear Overhauser Effect Spectroscopy (ROESY) spectra.

Beiträge zur Chemie der Pyrrolpigmente, XXIII [1] Die Struktur eines Bilatrien-abc-Derivates im gelösten Zustande / On the Chemistry of Pyrrole Pigments, XXIII [1] The Structure of a Bilatriene-abc Derivative in the State of Solution

1978 ◽  
Vol 33 (8) ◽  
pp. 924-931 ◽  
Author(s):  
Heinz Falk ◽  
Karl Grubmayr ◽  
Klaus Thirring
Keyword(s):  
Nitrogen Atom ◽  
Nuclear Overhauser Effect ◽  
The State ◽  
The Other ◽  
H Nmr ◽  
Overhauser Effect ◽  
Lactim Ether ◽  
Nuclear Overhauser ◽  
Shift Technique ◽  
Single Bonds

Abstract The (Z,Z,Z)-configuration of the mono-lactim-ether of an alkyl substituted bilatriene-abc, Etiobiliverdin-IV-γ, was established for chloroform solutions. Moreover the conformation of this molecule is a helical one (syn-syn-syn) with a twist along the single bonds at the methine groups of approximately 20°. The two tautomeric lactam-forms with a proton on one or the other nitrogen atom of the pyrromethene subsystem are indistin-guishable by the methods used in this investigation: 1H NMR pattern, Lanthanide induced shift technique and Nuclear Overhauser Effect measurements.

Preparation, characterization, and antioxidant properties of polystyrenes with 4-methoxyphenol end groups

1983 ◽  
Vol 61 (1) ◽  
pp. 124-127 ◽  
Author(s):  
Brian K. Hunter ◽  
Kenneth E. Russell ◽  
Ataa K. Zaghloul
Keyword(s):  
Molecular Weight ◽  
Nuclear Overhauser Effect ◽  
Average Molecular Weight ◽  
Antioxidant Properties ◽  
Low Molecular Weight ◽  
Nmr Studies ◽  
Overhauser Effect ◽  
End Groups ◽  
Nuclear Overhauser ◽  
C Nmr

Polystyrenes with 4-methoxyphenol end groups have been prepared by the cationic polymerization of styrene in the presence of the phenol. The products range from 1:1 adduct to polymer of number-average molecular weight close to 3000. The 1:1 adduct separated from the reaction mixture was shown by nuclear Overhauser effect studies to be 2-(1-methylbenzyl)-4-methoxyphenol. Only about half of the polymer molecules have 4-methoxyphenol end groups. 13C nmr studies indicate that the polystyrene chains are attached principally at the 2-position of the phenol. The activity of the polymer as an antioxidant is comparable to that of corresponding low molecular weight methoxyphenols including butylated hydroxyanisole.

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