N-Confused porphyrins: complexation and 1H NMR studies

2017 ◽  
Vol 41 (16) ◽  
pp. 7932-7937 ◽  
Author(s):  
Ilya A. Khodov ◽  
Olga V. Maltceva ◽  
Vladimir V. Klochkov ◽  
Oscar I. Koifman ◽  
Nugzar Zh. Mamardashvili
Keyword(s):  
Organic Solvents ◽  
1H Nmr ◽  
Nmr Studies ◽  
H Nmr ◽  
Vis Spectroscopy

The complexation of 2-aza-21-carba-tetraphenylporphyrin and 2-aza-2-methyl-5,10,15,20-tetraphenyl-21-carbaporphyrin with nickel and zinc acetates in organic solvents has been investigated by UV-Vis spectroscopy and 1H NMR.

Synthesis and spectral characterization of bis(β-diketonato)zirconium(IV) and -hafnium(IV) phthalocyaninates

2002 ◽  
Vol 06 (02) ◽  
pp. 114-121 ◽  
Author(s):  
L. A. Tomachynski ◽  
V. Ya. Chernii ◽  
S. V. Volkov
Keyword(s):  
Organic Solvents ◽  
Elemental Analysis ◽  
Central Atom ◽  
Spectral Characterization ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
Cl Atoms

The reaction of PcMCl 2 ( M = Zr , Hf ) with β-diketones is reported. 1 H NMR and elemental analysis suggest the substitution of two Cl atoms for two β-diketone fragments takes place as a result of this reaction and the complexes PcM(β-dik)2 are formed. All obtained complexes are stable and highly soluble in most organic solvents. The data from 1 H and 19 F NMR, and UV-vis spectroscopy suggest the coordination of two β-diketone ligands in a cis geometry about the central atom of the macrocycle. It was shown bis(β-diketonato)zirconium(IV) and hafnium(IV) phthalocyanines containing β-diketones with donor or acceptor groups or with bulky substituents can be obtained.

1H NMR Studies on the Cation Motions in Crystalline Cadmium Bromide Complexes [C(NH2)3]Cd2Br5, [(CH3)3NH]3Cd2Br7, and [i-C3H7NH3]CdBr3

2010 ◽  
Vol 65 (4) ◽  
pp. 499-502 ◽  
Author(s):  
Hideta Ishihara ◽  
Keizo Horiuchi ◽  
Yoshihiro Furukawa
Keyword(s):  
Activation Energy ◽  
1H Nmr ◽  
Molecular Motion ◽  
Higher Order ◽  
Methyl Groups ◽  
Nmr Studies ◽  
H Nmr ◽  
Cadmium Bromide

1H NMR T1 measurements of crystalline [C(NH2)3]Cd2Br5 showed a single minimum due to the C3 reorientation of the planar [C(NH2)3]+ ion with an activation energy (Ea) of 35.8 kJ mol−1. In [(CH3)3NH]3Cd2Br7 crystals, two T1 minima appeared which are assigned to the C3 reorientation of methyl groups in the [(CH3)3NH]+ cation with Ea = 13.0 kJ mol−1 and to the C3 reorientation of a whole cation around the molecular C3 axis with Ea = 28.9 kJ mol−1. In [i-C3H7NH3]CdBr3 crystals, a very broad T1 minimum appeared near 160 K which is assigned to the C3 reorientations of two methyl groups with Ea = 11.3 kJ mol−1 and of an NH3 group with Ea = 13.3 kJ mol−1 in the [i-C3H7NH3]+ ion, and another minimum with Ea = 23.5 kJ mol−1 near 300 K assigned to a higher order molecular motion of the cation.

119Sn, 13C and 1H NMR studies of aryloxy- and arylthio(1-butyl)stannanes

1989 ◽  
Vol 54 (9) ◽  
pp. 2386-2398 ◽  
Author(s):  
Antonín Lyčka ◽  
Jaroslav Holeček ◽  
Karel Handlíř
Keyword(s):  
Nmr Spectroscopy ◽  
Organic Compounds ◽  
1H Nmr ◽  
Organotin Compounds ◽  
Nmr Studies ◽  
Spectral Parameters ◽  
H Nmr ◽  
Mutual Comparison ◽  
Aromatic Systems

Two series of compounds have been prepared and studied by means of 119Sn, 13C, and 1H NMR spectroscopy, viz. aryloxy- and N-heteroaryloxytris(1-butyl)stannanes and their thio analogues Bu3SnER, and diaryloxy- and di(N-heteroaryloxy)bis(1-butyl)stannanes and their thio analogues Bu2Sn(ER)2, where E means oxygen or sulfur, Bu is 1-butyl, R = phenyl, 1-naphthyl, or 8-quinolyl. On the basis of mutual comparison of NMR spectral parameters of both series of organotin compounds and their comparison with NMR spectral parameters of analogous, purely organic compounds CH3ER it is possible to discuss the consequences of the presence of tin atoms in the organotin substituents and of nitrogen heteroatoms in the aromatic systems, and the therefrom following structure of the organotin compounds studied.

Molecular Complexes, 13. Weak Arene Complexes of Nitroaromatics. 1H NMR Studies of Conformations and Polar Effects. syn-anti Selectivity of 5-Nitrofurfural

2002 ◽  
Vol 57 (11) ◽  
pp. 1305-1314 ◽  
Author(s):  
Helmut Stamm ◽  
Hanns-Otto Strumm ◽  
Hannelore Jäckel ◽  
Barbro Beijer ◽  
Gerhard Schilling ◽  
...  
Keyword(s):  
1H Nmr ◽  
Aromatic Hydrocarbons ◽  
Molecular Complexes ◽  
Association Constants ◽  
Arene Complexes ◽  
Nmr Studies ◽  
H Nmr ◽  
Nmr Method

The refined 1H NMR method (AUS concept, CCl4) provided association constants K and approximate complex shifts IK for complexes of nitroaromatics A with aromatic hydrocarbons D. 5-Nitrofurfural (1) and benzene (B) or toluene (T) form syn-1B or syn-1T, respectively; a proton dependence of K indicates about 10% anti complexes. The dimer T2 of T additionally yields some 1T2 since IK values are 29-34% higher than for 1B. With naphthalene (N) or phenanthrene all protons of 1 provide the same K. Picrylacetone (2) and B form 2B and at least one 2BB adduct; published parameters of 2B and 2BB are inconsistent. 2 and N or M (1,3,5-trimethylbenzene) form only 1:1 complexes. All results are in accord with CH2COMe standing perpendicular to picryl. 2,4-Dinitrophenylacetone (3) in a rather flat conformation coordinates with a single stacking N centred over C-6; 3 yields two isomeric stacking complexes 3B and at least one edge-on 3B complex. 2-Chloro-5-nitropyridine (5) forms stacking complexes under repulsion of D by the ring N. In contrast to 1 and 4-nitrobenzaldehyde (6) 1,4-dinitrobenzene (7) and T form only a 1:1 complex that is stabilized by dipole-dipole attraction. Equal and unequal shielding of proton pairs (ortho or meta) in complexes of type 6B is discussed.

Structural Elements of Sporopollenin from the Pollen of Torreya californica Torr. (Gymnospermae): Using the 1H-NMR Technique

1999 ◽  
Vol 54 (7-8) ◽  
pp. 492-495 ◽  
Author(s):  
Friedhelm Ahlers ◽  
Jörg Lambert ◽  
Rolf Wiermann
Keyword(s):  
Organic Solvents ◽  
1H Nmr ◽  
Aromatic Compounds ◽  
Enzymatic Treatment ◽  
Typha Angustifolia ◽  
Structural Elements ◽  
High Similarity ◽  
H Nmr

Abstract Sporopollenin was isolated and purified from pollen of the gymnospermae Torreya californica using an enzymatic treatment followed by extraction with organic solvents. 1H -NMR (ID and 2D) was used for analysis of this biopolym er and reveals the presence of three phenolic com pounds. Comparison with the analysis of sporopollenin from the angiospermae Typha angustifolia L. shows high similarity between the aromatic compounds

Conformational study on ribonucleoside O-phosphonylmethyl derivatives by 1H NMR spectroscopy

1985 ◽  
Vol 50 (8) ◽  
pp. 1899-1905 ◽  
Author(s):  
Milena Masojídková ◽  
Jaroslav Zajíček ◽  
Miloš Buděšínský ◽  
Ivan Rosenberg ◽  
Antonín Holý
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Conformational Study ◽  
H Nmr ◽  
Conformational Properties

Conformational properties of ribonucleoside 5'-O-phosphonylmethyl derivatives have been determined by 1H NMR spectroscopy and compared with those of natural nucleosides and 5'-nucleotides.

1H NMR Conformational Studies in Water of Angiotensin II Analogues Modified at the N- and C-Termini: Interactions of the Aromatic Side Chains and Folding of the N-Terminal Domain

1994 ◽  
Vol 59 (11) ◽  
pp. 2523-2532 ◽  
Author(s):  
John Hondrelis ◽  
John Matsoukas ◽  
George Agelis ◽  
Paul Cordopatis ◽  
Ning Zhou ◽  
...  
Keyword(s):  
Shielding Effect ◽  
Resonance Spectroscopy ◽  
Nmr Studies ◽  
Previous Suggestion ◽  
Aminoisobutyric Acid ◽  
H Nmr ◽  
Neutral Ph ◽  
Angiotensin Ii Analogues ◽  
Proton Resonances ◽  
Cosy Nmr

The conformation of [Sar1]angiotensin II in water at neutral pH has been examined by proton magnetic resonance spectroscopy at 400 MHz and in particular by comparing its 1H NMR spectral data with those of analogues modified at positions 1,4 and 6, namely [Sar1,Cha8]ANGII, [Des Asp1,Cha8]ANGII, [Aib1,Tyr(Me)4]ANGII, [Aib1,Tyr(Me)4,Ile8]ANGII, [N-MeAib1,Tyr(Me)4]ANGII, [N-MeAib1,Tyr(Me)4,Ile8]ANGII, ANGIII and [Sar1,Ile8]ANGII. Assignment of all proton resonances in these analogues was made possible by 2D COSY NMR experiments. The H-2 and H-4 protons for the histidine ring in [Sar1]ANGII, ANGII and ANGIII were shielded compared with the same protons in [Sar1,Ile8]ANGII, [Sar1,Cha8]ANGII and [Des Asp1,Cha8]ANGII; this shielding effect was not disturbed upon methylation of the tyrosine hydroxyl and/or replacement of residue 1 (sarcosine or aspartic acid) with aminoisobutyric acid (Aib) or N-methyl aminoisobutyric acid (N-MeAib). These data are consistent with our previous suggestion based on NMR studies in neutral DMSO that a characteristic folded conformation for ANGII previously observed in non-polar solvents can also be detected in water at neutral pH, but to a lesser degree.

1H NMR studies of [N-MeAib1, Tyr(Me)4]ANGII and [N-MeAib1, Tyr(Me)4, Ile8]ANGII in dimethylsulfoxide by nuclear Overhauser effect (NOE) enhancement spectroscopy: cis-trans Isomerism of the His-Pro bond

1990 ◽  
Vol 55 (4) ◽  
pp. 1106-1111 ◽  
Author(s):  
John Matsoukas ◽  
Paul Cordopatis ◽  
Raghav Yamdagni ◽  
Graham J. Moore
Keyword(s):  
1H Nmr ◽  
Nuclear Overhauser Effect ◽  
Nmr Studies ◽  
Restricted Rotation ◽  
Overhauser Effect ◽  
Major Isomer ◽  
Conformational Properties ◽  
Nuclear Overhauser

The conformational properties of the Sarmesin analogues [N-MeAib1, Tyr(Me)4]ANGII and [N-MeAib1, Tyr(Me)4, Ile8]ANGII in hexadeutero-dimethysulfoxide were investigated by Nuclear Overhauser Effect (NOE) Enhancement Studies. Cis-trans isomers (ratio 1 : 6) due to restricted rotation of the His-Pro bond were observed. Interresidue interactions between the His Cα proton and the two Pro Cδ protons revealed that the major isomer was the trans.

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