Reactions of asymmetric carbodiimides with azoimide

1979 ◽  
Vol 44 (10) ◽  
pp. 2982-2986 ◽  
Author(s):  
Jan Světlík ◽  
Igor Hrušovský ◽  
Augustin Martvoň
Keyword(s):  
Nmr Spectroscopy ◽  
General Formula ◽  
H Nmr ◽  
Basic Nitrogen

Reaction of asymmetric aliphatic-aromatic and diaryl carbodiimides with HN3 leads to 1,5-disubstituted tetrazoles. Carbodiimides of general formula C6H5-N=C=N-R (R = alkyl) from an adduct at C=N bond exclusively at a less basic nitrogen, i.e. near phenyl whereas those with R = aryl afford a 1 : 1 mixture of products. 1H-NMR spectroscopy revealed an aminotetrazole-iminotetrazoline tautomerism of the prepared 1=phenyl-5-alkylaminotetrazoles, which undergo isomerization to 1-alkyl-5-anilinotetrazoles.

Strukturuntersuchungen an Dihalogen(diphosphan)nickel-KompIexen in Lösung mit Differential-Puls-Polarographie / Structure Analysis of Dihalogeno(diphosphine)nickel Complexes in Solution with Differential Puls Polarography

1998 ◽  
Vol 53 (7) ◽  
pp. 694-698 ◽  
Author(s):  
Martin Mutz ◽  
Hans Peter Latscha
Keyword(s):  
Nmr Spectroscopy ◽  
General Formula ◽  
Structure Analysis ◽  
Nickel Complexes ◽  
H Nmr

Abstract The structures of twelve dihalogeno(diphosphine)nickel complexes of the general formula [NiX2(PR′2R′)2] (X = Cl, Br and I; R′ resp. R″ = -C2H5 or -C6H5) were analyzed in solution by differential puls polarography and 1H-NMR spectroscopy as a function of temperature.

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.

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

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1576-1586 ◽  
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.

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

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).

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

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.

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

1988 ◽  
Vol 43 (5-6) ◽  
pp. 473-475 ◽  
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.

scholarly journals Water-soluble β-aminobisulfonate building blocks for pH and Cu2+ indicators

RSC Advances ◽  
2016 ◽  
Vol 6 (88) ◽  
pp. 84712-84721 ◽  
Author(s):  
Maria A. Cardona ◽  
Marina Kveder ◽  
Ulrich Baisch ◽  
Michael R. Probert ◽  
David C. Magri
Keyword(s):  
Nmr Spectroscopy ◽  
Building Blocks ◽  
Water Soluble ◽  
Visible Absorption ◽  
H Nmr ◽  
Uv Visible

Two phenyl β-aminobisulfonate ligands characterised by UV-visible absorption, EPR and 1H NMR spectroscopy exhibit evidence for binding with Cu2+ in water and methanol.

Quantitative Analysis of Amygdalin and Prunasin in Prunus serotina Ehrh. using 1 H-NMR Spectroscopy

2013 ◽  
Vol 25 (2) ◽  
pp. 122-126 ◽  
Author(s):  
Lúcia P. Santos Pimenta ◽  
Menno Schilthuizen ◽  
Robert Verpoorte ◽  
Young Hae Choi
Keyword(s):  
Quantitative Analysis ◽  
Nmr Spectroscopy ◽  
Prunus Serotina ◽  
H Nmr

Spinel Formation from Magnesium Aluminium Double Alkoxides

1986 ◽  
Vol 73 ◽  
Author(s):  
Kenneth Jones ◽  
Thomas J. Davies ◽  
Harold G. Emblem ◽  
Peter Parkes
Keyword(s):  
Nmr Spectroscopy ◽  
General Formula ◽  
Metal Atom ◽  
Vacuum Distillation ◽  
Viscosity Measurements ◽  
Spinel Formation ◽  
Bonding Phase ◽  
Xrd Studies ◽  
Aluminium Alkoxide

ABSTRACTDouble alkoxides of the general formula Mg[Al(OR)4]2 where R is iso-Pr or sec-Bu were prepared by reacting aluminium and magnesium metals together with the alcohol ROH and purified by vacuum distillation. They were characterised by IR, proton and 27Al NMR spectroscopy and MW determination. A magnesium aluminium double alkoxide was also prepared by treating the commercially available aluminium alkoxide ‘Aliso B’ [a mixed aluminium (iso-propoxide)(sec-butoxide)] with magnesium and iso-propanol. Treatment of magnesium aluminium double alkoxides with water and an alkanolamine (preferably triethanolamine) gives a rigid coherent gel. Viscosity measurements and 27Al NMR spectroscopy suggest that the double alkoxide does not break down to its constituents during hydrolysis. The air-dried gel was shown by XRD to convert quantitatively to spinel on firing to 1500°C. The resistance of the double alkoxide moiety to hydrolysis explains the ease of conversion to spinel on firing. The gel has been used to bind alumina and magnesia grain. Gels suitable for binding refractory grain were obtained only when the alkanolamine content corresponded to one alkanolamine group per metal atom. Electron micrographic and XRD studies showed that in fired refractory pieces, the bonding phase was spinel.

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