scholarly journals Linkage of α-cyclodextrin-terminated poly(dimethylsiloxanes) by inclusion of quasi bifunctional ferrocene

2013 ◽  
Vol 9 ◽  
pp. 1278-1284 ◽  
Author(s):  
Helmut Ritter ◽  
Berit Knudsen ◽  
Valerij Durnev
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Light Scattering ◽  
Ir Spectroscopy ◽  
Nmr Spectra ◽  
H Nmr ◽  
Scattering Measurements ◽  
End Groups ◽  
2D Roesy ◽  
2D Roesy Nmr

We report the noncovalent linkage of terminally substituted oligo(dimethylsiloxanes) bearing α-cyclodextrins (α-CD) as host end groups for the cyclopentadienyl rings of ferrocene. This double complexation of unsubstituted ferrocene leads to a supramolecuar formation of the siloxane strands. Structural characterization was performed by the use of 1H NMR and IR spectroscopy and by mass spectrometry. Electron microscopy studies and dynamic light scattering measurements show a significant decrease of the derivative size after the complexation with ferrocene. In addition, further evidence for the successful complexation of the end groups was verified by the shifts of the protons in the 1H NMR spectra and in the correlation signals of the 2D ROESY NMR spectra.

scholarly journals Calix[4]arene-click-cyclodextrin and supramolecular structures with watersoluble NIPAAM-copolymers bearing adamantyl units: “Rings on ring on chain”

2010 ◽  
Vol 6 ◽  
pp. 784-788 ◽  
Author(s):  
Bernd Garska ◽  
Monir Tabatabai ◽  
Helmut Ritter
Keyword(s):  
Mass Spectrometry ◽  
Light Scattering ◽  
Ir Spectroscopy ◽  
Complex Formation ◽  
Dynamic Light Scattering ◽  
Click Reaction ◽  
Supramolecular Complex ◽  
H Nmr ◽  
Microwave Assisted ◽  
Ph Dependent

We describe the calixarene-cyclodextrin-coupling via click reaction starting from 5,11,17,23-tetra-tert-butyl-25,27-dipropargylether-26,28-hydroxy-calix[4]arene (calix[4]arene-dipropargylether) (2) onto 6I-azido-6I-deoxycyclomaltoheptaose (3) under microwave assisted conditions. The coupling was proven by MALDI-TOF mass spectrometry, 1H NMR and IR-spectroscopy. The pH dependent supramolecular complex formation with poly(NIPAAM) bearing attached adamantyl units was investigated by dynamic light scattering (DLS) and turbidity measurements.

Rotationsbarriere der Endgruppen bei Poly- methinoxonolen verschiedener Kettenlänge / Rotation Barrier of the End Groups of Polymethine Oxonols with Different Chain Lengths

1976 ◽  
Vol 31 (8) ◽  
pp. 1017-1018 ◽  
Author(s):  
H. Oehling ◽  
F. Baer
Keyword(s):  
Nmr Spectra ◽  
Rotation Barrier ◽  
Free Enthalpy ◽  
Temperature Dependent ◽  
Restricted Rotation ◽  
H Nmr ◽  
Enthalpy Of Activation ◽  
End Groups ◽  
Electron Contribution ◽  
Chain Lengths

Abstract Polymethine oxonols show temperature dependent 1H-NMR-spectra because of restricted rotation of the end groups. The dependence of the value of the corresponding free enthalpy of activation AGt on the length of the poly-methine chain can be explained by the change of the π-electron contribution to ⊿G≠.

Synthesis, Spectroscopic Properties, and Crystal Structure of the Oxonium Acid [H(OEt2)2]+[Ti2Cl9]–

2003 ◽  
Vol 58 (8) ◽  
pp. 745-750 ◽  
Author(s):  
Stefan Rannabauer ◽  
Tassilo Habereder ◽  
Heinrich Nöth ◽  
Wolfgang Schnick
Keyword(s):  
Crystal Structure ◽  
Ir Spectroscopy ◽  
Single Crystals ◽  
Nmr Spectra ◽  
Spectroscopic Properties ◽  
Partial Hydrolysis ◽  
Distorted Tetrahedron ◽  
Methyl Carbon ◽  
H Nmr ◽  
The Stability

The oxonium acid [H(OEt2)2]+[Ti2Cl9]− (1) was obtained by the reaction of TiCl4 with Et2O in n-pentane and subsequent partial hydrolysis. Suitable single crystals of 1 were obtained by sublimation at 5° C ([H(OEt2)2]+[Ti2Cl9]−, P212121 (no. 19), Z = 4, a = 1101.08(8), b = 1328.4(2), c = 1525.0(2) pm, T = 193(2) K, 4489 independent reflections, 197 parameters, R1 = 0.049). The cation is made up from two independent Et2O molecules and one disordered proton on two split positions. Both ether molecules exhibit a W form, and their molecular planes include an angle of 74.1(7)°. Thus a distorted tetrahedron is formed by the four methyl carbon atoms of the two ether molecules. The distance O···O amounts to 237.7(1) pm. The proton of the cation was characterized both by 1H NMR (CDCl3, T = 23 °C: δ = 11.7 ppm, w1/2 = 100 Hz) and IR spectroscopy (3120 cm−1, ν vbr). The [Ti2Cl9]− ion consists of two face sharing octahedra. 47Ti and 49Ti NMR spectra were recorded in solution (CH2Cl2, T = 23 °C: δ 49Ti = 137 ppm, w1/2 = 175 Hz; δ 47Ti = −124 ppm, w1/2 = 250 Hz). The absence of a signal for TiCl4 at δ 49Ti = 0 ppm indicates the stability of the dinuclear anion in solution.

scholarly journals Separation and characterization of environmental nano- and submicron particles

2016 ◽  
Vol 35 (4) ◽  
pp. 185-199 ◽  
Author(s):  
Mikhail S. Ermolin ◽  
Petr S. Fedotov
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Light Scattering ◽  
Membrane Filtration ◽  
Optical Emission ◽  
Submicron Particles ◽  
Characterization Methods ◽  
Anthropogenic Processes ◽  
Spectroscopy Optical

AbstractThe investigation of environmental nano- and submicron particles is needed for the assessment of their impact on the environment and human health as well as for understanding various natural and anthropogenic processes. Nano- and submicron particles have an increased mobility, may serve as a “carrier” for toxic and nutrient substances, and hence are of particular interest. So far, there is a lack of knowledge about source, behavior, fate, and toxicity of environmental nano- and submicron particles. This article is focused on the separation and characterization methods, which are currently used for their investigation. The application of sedimentation, centrifugation, membrane filtration, and field- and flow-based techniques to the separation of nano- and submicron particles are discussed. The advantages and limitations of the techniques are briefly summarized. Among characterization/analysis methods, a special attention is given to electron microscopy, light scattering as well as atomic absorption spectroscopy, optical emission, and mass spectrometry.

A pyridinium modified β-cyclodextrin: an ionic supramolecular ligand for palladium acetate in C–C coupling reactions in water

2016 ◽  
Vol 18 (20) ◽  
pp. 5518-5528 ◽  
Author(s):  
Raihana Imran Khan ◽  
Kasi Pitchumani
Keyword(s):  
Mass Spectrometry ◽  
Light Scattering ◽  
Ir Spectroscopy ◽  
Water Soluble ◽  
Palladium Acetate ◽  
Coupling Reactions ◽  
Visible Spectroscopy ◽  
Ft Ir ◽  
Uv Visible ◽  
Ft Ir Spectroscopy

An ionic Pd(ii) complex stabilized by a water soluble pyridinium modified β-cyclodextrin was prepared and characterized by NMR, mass spectrometry, FT-IR spectroscopy, UV-visible spectroscopy and DLS (dynamic light scattering).

scholarly journals Analysis of Inclusion Complexes of Clotrimazole and Differently Substituted α, β and γ Cyclodextrins by NMR Spectroscopy

2001 ◽  
Vol 71 (3) ◽  
pp. 497-506
Author(s):  
Hajnal Kelemen ◽  
Bela Noszal ◽  
Gabor Orgovan
Keyword(s):  
Nmr Spectroscopy ◽  
Stability Constant ◽  
Inclusion Complexes ◽  
Antifungal Agent ◽  
Nmr Spectra ◽  
High Stability ◽  
Cyclodextrin Derivatives ◽  
Cyclodextrin Complexes ◽  
2D Roesy ◽  
2D Roesy Nmr

Clotrimazole, a widely used imidazole-type antifungal agent and its cyclodextrin complexes were studied. Stoichiometries, structures and stability constants of the inclusion complexes with fourteen different cyclodextrin derivatives were characterized using NMR spectroscopy as primary technique. The cyclodextrin complexes were found to be of high stability (logK ] 2). 2D ROESY NMR spectra revealed the formation of isomeric complexes with every cyclodextrin studied. The highest stability constant was observed with sulfobutylated β-CD, and interestingly enough the heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin showed the lowest stability.

The chlorosome of Chlorobaculum tepidum: Size, mass and protein composition revealed by electron microscopy, dynamic light scattering and mass spectrometry-driven proteomics

PROTEOMICS ◽  
2011 ◽  
Vol 11 (14) ◽  
pp. 2867-2880 ◽  
Author(s):  
Kalliopi Kouyianou ◽  
Pieter-Jan De Bock ◽  
Shirley A. Müller ◽  
Antigoni Nikolaki ◽  
Apostolos Rizos ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Protein Composition ◽  
Chlorobaculum Tepidum

Study of Amino-Imino Tautomerism in Derivatives of 2-, 4- and 6-Aminonicotinic Acid

1994 ◽  
Vol 59 (9) ◽  
pp. 2057-2068 ◽  
Author(s):  
Svatava Smrčková ◽  
Kristina Juricová ◽  
Viktor Prutianov
Keyword(s):  
Ir Spectroscopy ◽  
Hydrogen Bonds ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Amino Derivative ◽  
Ionic Character ◽  
H Nmr ◽  
Amino Derivatives ◽  
Derivatives Of ◽  
C Nmr

13C NMR spectra of p-nitrobenzoyl 2-, 4-, and 6-aminopyridine-3-carboxylates, their hydrochlorides, trifluoroacetates and 1-benzyl derivatives were studied. As found from the chemical shifts of pyridine carbon atoms C-2, C-4 and C-6, the free bases exist in the amino form whereas hydrochlorides and 1-substituted pyridinium derivatives in the imino form. Trifluoroacetates of the 2- and 6-amino derivatives have structure similar to that of amidiniumcarboxylates (parallel hydrogen bonds and partially ionic character) whereas trifluoroacetate of the 4-amino derivative is structurally close to the corresponding hydrochloride. The found structures were confirmed by 1H NMR and IR spectroscopy.

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