ChemInform Abstract: Kinetics of the Dehydration of the β-Cages of Sodium Faujasites as Studied by H NMR Spectroscopy.

We describe the synthesis of bromo-tert-butyloxycarbonyl (Br-t-BOC)-amino-protected monomers 2-((1-bromo-2-methylpropan-2-yl)oxycarbonylamino)ethyl (meth)acrylate 3a,b. For this purpose, 2-isocyanatoethyl (meth)acrylate 1a,b was reacted with 1-bromo-2-methylpropan-2-ol (2a). The free radical polymerization of (Br-t-BOC)-aminoethyl (meth)acrylates 3a,b yielded poly((Br-t-BOC)-aminoethyl (meth)acrylate) 6a,b bearing protected amino side groups. The subsequent solvolysis of the Br-t-BOC function led to the new polymers poly(2-aminoethyl (meth)acrylate) 8a,b with protonated free amino groups. The monomers and the resulting polymers were thoroughly characterized by 1H NMR, IR, GPC and DSC methods. The kinetics of the deprotection step was followed by 1H NMR spectroscopy. The solvent polarity and neighboring group effects on the kinetics of deprotection are discussed.

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A NMR Study of the Exchange Kinetics of the Nonamethylimidodiphosphoramide with its Complexes of Diamagnetic Cations

Zeitschrift für Naturforschung B ◽

10.1515/znb-1978-0629 ◽

1978 ◽

Vol 33 (6) ◽

pp. 684-685 ◽

Cited By ~ 1

Author(s):

P. R. Rubini ◽

L. Rodehüser ◽

J.-J. Delpuech

Keyword(s):

Nmr Spectroscopy ◽

Ligand Exchange ◽

H Nmr ◽

Nmr Study ◽

Exchange Kinetics ◽

Monodentate Ligands ◽

Kinetics Of

Abstract The ligand exchange on nonamethylimidodiphosphoramide (NIPA) complexes is found to be very slow comparatively to analogous monodentate ligands; the rates determined by 1H or 31P NMR spectroscopy are: k(25°C)=4.3 × 10-2 s-1; 31.6 s-1 • M-1; 3.7 × 104 S-1 • M-1 and 1.35 × 104 s-1 · M-1 for Mg2+, Ca2+, Sr2+ and Li+ cations respectively. For the Al3+, Ga3+, In3+ and Be2+ ions no exchange could be detected by 1H NMR spectroscopy up to 120 °C, indicating rates lower than about 10-3 s-1

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Kinetics of the Dehydration of the β-Cages of Sodium Faujasites as Studied by H-NMR Spectroscopy

Berichte der Bunsengesellschaft für physikalische Chemie ◽

10.1002/bbpc.19920960406 ◽

1992 ◽

Vol 96 (4) ◽

pp. 545-549 ◽

Cited By ~ 3

Author(s):

W. D. Basler ◽

H. T. Lechert ◽

D. Carboo ◽

A. Knöchel

Keyword(s):

Nmr Spectroscopy ◽

H Nmr ◽

Kinetics Of

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Perhalogenated 2-pyridylporphyrin complexes: synthesis, self-coordinating aggregation properties, and catalytic studies

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424602000087 ◽

2002 ◽

Vol 06 (01) ◽

pp. 50-57 ◽

Cited By ~ 26

Author(s):

Júlio S. Rebouças ◽

Maria Eliza M. D. de Carvalho ◽

Ynara M. Idemori

Keyword(s):

Nmr Spectroscopy ◽

First Generation ◽

Reduction Potential ◽

Catalyst Concentration ◽

Acid Base ◽

H Nmr ◽

Highly Active ◽

Ph Dependent ◽

Metal Insertion ◽

Kinetics Of

The synthesis of 2, 3, 7, 8, 12, 13, 17, 18-octabromo-meso-tetrakis(2-pyridyl)porphyrin, H 2 Br 8 T 2 PyP , is described, including the comparison of four attempted methods for the demetallation of ZnBr 8 T 2 PyP . One of the methods represents a strategy of demetallation based on the acid-base properties of the macrocycle, the solvent-dependent kinetics of metal insertion into porphyrins and the pH -dependent solubility of the 2-pyridylporphyrin derivatives in water. Self-coordinating aggregation of ZnBr 8 T 2 PyP in non-coordinating solvents was verified by 1 H NMR spectroscopy. The Mn(III)/Mn(II) redox potential for MnBr 8 T 2 PyPCl is 0.38 V higher than the reduction potential measured for its first-generation analogue, MnT 2 PyPCl . Cyclohexane hydroxylation by iodosylbenzene was performed in CH3 CN catalyzed by MnBr 8 T 2 PyPCl and MnT 2 PyPCl . MnBr 8 T 2 PyPCl was highly active, even at low concentration (5 × 10−5 M ), but perhalogenation did not account for oxidative robustness. At such a low catalyst concentration, MnT 2 PyPCl exhibited no activity as inferred by comparison to blank experiments.

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Catalytic activity of rhodium(I) complexes containing (ω-trimethylsilylalkyl)diphenylphosphines

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19802219 ◽

1980 ◽

Vol 45 (8) ◽

pp. 2219-2223 ◽

Cited By ~ 6

Author(s):

Marie Jakoubková ◽

Martin Čapka

Keyword(s):

Catalytic Activity ◽

Nmr Spectroscopy ◽

Ir Spectroscopy ◽

Electron Density ◽

Phosphorus Atom ◽

Proton Acceptor ◽

Trimethylsilyl Group ◽

Kinetics Of

Kinetics of homogenous hydrogenation of 1-heptene catalysed by rhodium(I) complexes prepared in situ from μ,μ'-dichloro-bis(cyclooctenerhodium) and phosphines of the type RP(C6H5)2 (R = -CH3, -(CH2)nSi(CH3)3; n = 1-4) have been studied. The substitution of the ligands by the trimethylsilyl group was found to increase significantly the catalytic activity of the complexes. The results are discussed in relation to the electron density on the phosphorus atom determined by 31P NMR spectroscopy and to its proton acceptor ability determined by IR spectroscopy.

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

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19851899 ◽

1985 ◽

Vol 50 (8) ◽

pp. 1899-1905 ◽

Cited By ~ 4

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.

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Monitoring the encapsulation of chlorin e6 derivatives into polymer carriers by NMR spectroscopy

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424619501815 ◽

2019 ◽

Vol 23 (11n12) ◽

pp. 1576-1586 ◽

Cited By ~ 1

Author(s):

Sara Pfister ◽

Luca Sauser ◽

Ilche Gjuroski ◽

Julien Furrer ◽

Martina Vermathen

Keyword(s):

Relaxation Time ◽

Nmr Spectroscopy ◽

Core Region ◽

Chlorin E6 ◽

Polypropylene Glycol ◽

Polymer Carriers ◽

H Nmr ◽

Line Shape Analysis ◽

Dynamic Methods ◽

Derivatives Of

The encapsulation of five derivatives of chlorin e6 with different hydrophobicity and aggregation properties into a series of five poloxamer-type triblock copolymer micelles (BCMs) with varying numbers of polyethylene and polypropylene glycol (PEG, PPG) units was monitored using 1H NMR spectroscopy. NMR chemical shift and line shape analysis, as well as dynamic methods including diffusion ordered spectroscopy (DOSY) and T1 and T2 relaxation time measurements of the chlorin and the polymer resonances, proved useful to assess the chlorin–BCM compatibility. The poloxamers had high capability to break up aggregates formed by chlorins up to intermediate hydrophobicity. Physically entrapped chlorins were always localized in the BCM core region. The loading capacity correlated with chlorin polarity for all poloxamers among which those with the lowest number of PPG units were most efficient. DOSY data revealed that relatively weakly aggregating chlorins partition between the aqueous bulk and micellar environment whereas more hydrophobic chlorins are well retained in the BCM core region, rendering these systems more stable. T1 and T2 relaxation time measurements indicated that motional freedom in the BCM core region contributes to encapsulation efficiency. The BCM corona dynamics were rather insensitive towards chlorin entrapment except for the poloxamers with short PEG chains. The presented data demonstrate that 1H NMR spectroscopy is a powerful complementary tool for probing the compatibility of porphyrinic compounds with polymeric carriers such as poloxamer BCMs, which is a prerequisite in the development of stable and highly efficient drug delivery systems suitable for medical applications like photodynamic therapy of tumors.

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Different submicellar solubilization mechanisms revealed by 1H NMR and 2D diffusion ordered spectroscopy (DOSY)

Physical Chemistry Chemical Physics ◽

10.1039/d0cp00429d ◽

2020 ◽

Vol 22 (19) ◽

pp. 11075-11085

Author(s):

Mengjian Wu ◽

Zhaoxia Wu ◽

Shangwu Ding ◽

Zhong Chen ◽

Xiaohong Cui

Keyword(s):

Nmr Spectroscopy ◽

Sodium Dodecyl Sulfate ◽

1H Nmr ◽

Sodium Dodecyl ◽

Butyl Methacrylate ◽

H Nmr ◽

Molecular Scale ◽

Two Systems ◽

Dodecyl Sulfate ◽

Triton X

Different submicellar solubilization mechanisms of two systems, Triton X-100/tetradecane and sodium dodecyl sulfate (SDS)/butyl methacrylate, are revealed on the molecular scale by 1H NMR spectroscopy and 2D diffusion ordered spectroscopy (DOSY).

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Tautomerisation in 1-(4-Methylphenylazo)naphthalen-2-ol and 2-(4-Methylphenylazo)-4-methylphenol: A Crystallographic and 13C{1H}NMR Study

Journal of Chemical Research ◽

10.1177/174751989902300304 ◽

1999 ◽

Vol 23 (3) ◽

pp. 178-179

Author(s):

Wendy I. Cross ◽

Kevin R. Flower ◽

Robin G. Pritchard

Keyword(s):

Acetic Acid ◽

Nmr Spectroscopy ◽

Resonant Frequency ◽

X Ray Diffraction ◽

X Ray ◽

H Nmr ◽

Nmr Study ◽

Acetic Acid Esters ◽

Acid Esters ◽

Equivalent Carbon

The acetic acid esters of 1-(4-methylphenylazo)naphthalen-2-ol 1 and 2-(4-methylphenylazo)-4-methylphenol 3 are prepared and characterised by single crystal X-ray diffraction studies and 13C{1H}NMR spectroscopy; the position of the C(2)13C resonance for the ester is used to predict the position of resonant frequency of the equivalent carbon in the parent alcohols and hence, calculate the position of the azo-hydrazone equilibrium in these compounds.

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3-Hydroxy Retinal, a New Chromophore Identified in Insect Eyes: HPLC Separation and NMR Spectroscopic Identification of the Oxime Forms

Zeitschrift für Naturforschung C ◽

10.1515/znc-1988-5-626 ◽

1988 ◽

Vol 43 (5-6) ◽

pp. 473-475 ◽

Cited By ~ 2

Author(s):

Wolfgang Gärtner ◽

Anette Plangger

Keyword(s):

Nmr Spectroscopy ◽

Separation System ◽

Hplc Separation ◽

H Nmr ◽

Spectroscopic Identification

3-Hydroxy retinal acts as visual chromophore instead of retinal in the eyes of several insect orders. A HPLC separation system of the aldehyde and oxime isomers and their identification by 400 MHz 1H NMR spectroscopy is described.

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