Changes in macrocyclic aromaticity and formation of a charge-separated state by complexation of expanded porphyrin and C60

2019 ◽  
Vol 55 (57) ◽  
pp. 8301-8304 ◽  
Author(s):  
Won-Young Cha ◽  
Ahreum Ahn ◽  
Taeyeon Kim ◽  
Juwon Oh ◽  
Rashid Ali ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
H Nmr ◽  
Expanded Porphyrins ◽  
Nucleus Independent Chemical Shift ◽  
A Charge ◽  
Chemical Shift Calculations ◽  
Expanded Porphyrin

Significant changes of macrocyclic aromaticity in expanded porphyrins through C60 complexation were studied by 1H NMR spectroscopy and nucleus-independent chemical shift calculations.

Proof of ion-pair structures in ammonium-based protic ionic liquids using combined NMR and DFT/PCM-based chemical shift calculations

2017 ◽  
Vol 19 (36) ◽  
pp. 25033-25043 ◽  
Author(s):  
M. Lozynski ◽  
J. Pernak ◽  
Z. Gdaniec ◽  
B. Gorska ◽  
F. Béguin
Keyword(s):  
Ionic Liquids ◽  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Self Assembly ◽  
Ion Pair ◽  
The Self ◽  
Prediction Methods ◽  
Protic Ionic Liquids ◽  
H Nmr ◽  
Chemical Shift Calculations

The self-assembly of triethylammonium bis(trifluoromethylsulfonyl)imide, i.e. [(C2H5)3NH][TFSI], in chloroform and aqueous solutions has been investigated using 1H NMR spectroscopy and computational (DFT/PCM prediction) methods.

Chemical Shift Nonequivalence of Enantiomers of Amino Acid Derivatives in 1H NMR and 19F NMR Spectroscopy Induced by L-Chirasil- Val.

1992 ◽  
Vol 47 (7) ◽  
pp. 1034-1036 ◽  
Author(s):  
Bernhard Koppenhoefer ◽  
Michael Hummel
Keyword(s):  
Amino Acid ◽  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Methyl Esters ◽  
Enantiomeric Purity ◽  
Peak Splitting ◽  
H Nmr ◽  
Acid Methyl ◽  
Amino Acid Methyl Esters

Enantiomers of N-trifluoroacetyl-amino acid methyl esters in CC14 solution, after addition of the chiral polysiloxane (L)-Chirasil-Val, display a chemical shift nonequivalence ΔΔδ in both 1H NMR and 19F NMR spectroscopy. The effects found for the leucine and valine derivatives can be correlated with the thermodynamic parameters of interaction in the undiluted system, as determined by gas chromatography. In CDC13 solution, no peak splitting was observed. The method is potentially useful for the determination of the enantiomeric purity of substrates of low volatility.

Benzoxazine Oligomers:  Evidence for a Helical Structure from Solid-State NMR Spectroscopy and DFT-Based Dynamics and Chemical Shift Calculations

2003 ◽  
Vol 125 (19) ◽  
pp. 5792-5800 ◽  
Author(s):  
Gillian R. Goward ◽  
Daniel Sebastiani ◽  
Ingo Schnell ◽  
Hans Wolfgang Spiess ◽  
Ho-Dong Kim ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Solid State Nmr ◽  
Helical Structure ◽  
Solid State Nmr Spectroscopy ◽  
Chemical Shift Calculations

Synthesis of azabenziporphyrinoids by SN Ar reactions

2020 ◽  
Vol 24 (05n07) ◽  
pp. 794-801 ◽  
Author(s):  
Masataka Umetani ◽  
Takayuki Tanaka ◽  
Atsuhiro Osuka
Keyword(s):  
Lead Dioxide ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Oxidation Reactions ◽  
Substitution Reactions ◽  
H Nmr ◽  
Nucleus Independent Chemical Shift ◽  
Bond Alternation ◽  
Acid Catalyzed ◽  
Chemical Shift Calculations

While most of porphyrins and related macrocycles have been synthesized by classical acid-catalyzed condensation and oxidation reactions, nucleophilic aromatic substitution reactions have recently emerged as a new protocol to construct novel porphyrinoids. [Formula: see text]-Dibromotripyrrin 3 was developed as a useful building block composed of three pyrrolic segments and two meso-carbons, which was allowed to react with various nucleophiles. Herein, we applied this strategy to synthesize carbaporphyrinoids containing two nitrogen atoms at the meso-positions. Reaction of [Formula: see text]-dibromotripyrrin 3 with meta- and para-phenylenediamine gave diazabenziporphyrins 8 and 9in good yields. Their oxidized species 12 and 13 were generated by facile oxidation with lead dioxide. While diaza-meta-benziporphyrin 12 exhibited nonaromatic characteristics, diaza-para-benziporphyrin 13 was revealed to be aromatic in view of [Formula: see text]H NMR, bond-alternation, and nucleus-independent-chemical-shift calculations. Curiously, aza-meta-benzicorrole 11 was obtained in a low yield by intramolecular cyclization reaction of [Formula: see text]-anilino-[Formula: see text]-bromotripyrrin with potassium carbonate.

scholarly journals Investigations of Uranyl Fluoride Sesquihydrate (UO2F2·1.57H2O): Combining 19F Solid-State MAS NMR Spectroscopy and GIPAW Chemical Shift Calculations

2018 ◽  
Vol 122 (34) ◽  
pp. 6873-6878 ◽  
Author(s):  
Michael A. DeVore ◽  
Christopher A. Klug ◽  
Maria R. Kriz ◽  
Lindsay E. Roy ◽  
Matthew S. Wellons
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Mas Nmr ◽  
Chemical Shift Calculations

Preparation and properties of rhodium(I) and iridium(I) diolefin complexes of heterodifunctional phosphorus–imine chelating ligands and a related iminophosphine. 103Rh NMR parameters of the rhodium complexes obtained via indirect two-dimensional 31P, 103Rh{1H} NMR spectroscopy

1995 ◽  
Vol 73 (5) ◽  
pp. 635-642 ◽  
Author(s):  
David J. Law ◽  
Glen Bigam ◽  
Ronald G. Cavell
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
1H Nmr Spectroscopy ◽  
Rhodium Complexes ◽  
Chelating Ligands ◽  
Two Dimensional ◽  
H Nmr ◽  
Nmr Parameters ◽  
Nmr Data

Treatment of [M(cod)Cl]2 (M = Rh, Ir) with iminophosphoranophosphine ligands of the type Ph2PQP(Ph2)=NSiMe3 (Q = CH2, CH2CH2, 1,2-C6H4) afforded the new metallacycles [Formula: see text] through elimination of Me3SiCl, ultimately "anchoring" the ligand to the metal through a metal–nitrogen σ bond. The phosphine functionality completes the chelate. Cationic complexes of the type [M(cod)L2]+PF6− (M = Rh or Ir; L2 = Ph2PQPPh2NR where Q = CH2, CH(CH3), 1,2-C6H4, and R = p-C6F4CN, C6H2F(NO2)2, and C6H3(NO2)2 or L = Ph2PN=C(H)Ph) were readily prepared by treating [M(cod)Cl]2 with L2 and KPF6. The detection and chemical shift determination of the insensitive 103Rh nucleus was easily accomplished via 31P detected indirect two-dimensional 31P, 103Rh{1H} NMR spectroscopy. The 103Rh, 1H, and 31P NMR data are discussed. Keywords: rhodium, iridium, phosphoranimine, iminophosphine, Rh NMR.

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