A NUCLEAR MAGNETIC RESONANCE INVESTIGATION OF MOLECULAR COMPLEXES OF POLAR MOLECULES IN AROMATIC SOLVENTS

1962 ◽  
Vol 40 (7) ◽  
pp. 1285-1290 ◽  
Author(s):  
J. V. Hatton ◽  
W. G. Schneider
Keyword(s):  
Molecular Complex ◽  
Molecular Complexes ◽  
Large Temperature ◽  
Proton Resonance ◽  
Aromatic Solvents ◽  
Temperature Coefficients ◽  
Molecular Complex Formation ◽  
Nuclear Magnetic Resonance Investigation ◽  
Polar Solutes ◽  
Magnetic Resonance Investigation

In order to confirm the existence of specific molecular complexes in solutions of polar solutes in aromatic solvents previously proposed, the temperature variation of the proton resonance shifts of the solutes acetonitrile, p-benzoquinone, and N,N-dimethylformamide in 5 mole% concentration in toluene were measured. The large temperature coefficients of the solute shifts observed strongly support molecular complex formation. For the same solutes dissolved in methylcyclohexane the temperature coefficients were negligibly small. The temperature at which onset of free rotation of the N-dimethyl group of N,N-dimethylformamide occurs is solvent and concentration dependent. These observations are consistent with the proposed geometry of the molecular complex in the aromatic solvents.

A NUCLEAR MAGNETIC RESONANCE INVESTIGATION OF THE PROTONATION OF AMIDES IN FLUOROSULPHURIC ACID

1963 ◽  
Vol 41 (1) ◽  
pp. 148-155 ◽  
Author(s):  
R. J. Gillespie ◽  
T. Birchall
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nitrogen Atom ◽  
Low Temperatures ◽  
Carbonyl Oxygen ◽  
Proton Resonance ◽  
Resonance Investigation ◽  
Nuclear Magnetic Resonance Investigation ◽  
Peak Areas ◽  
Magnetic Resonance Investigation

The proton resonance spectra of solutions of acetamide, N,N-dimethylacetamide, formamide, and N,N-dimethylformamide in fluorosulphuric acid have been studied at temperatures between 25° and −98°. At low temperatures a new peak appears in the spectra of solutions of all four compounds which is not present at room temperatures and which, from peak areas and other consideration, may be assigned with certainty to the [Formula: see text] group. It is thereby unambiguously established that these amides protonate on the carbonyl oxygen and not on the nitrogen atom.

Topography and electrical conductivity of films of molecular complexes of zinc(II)tetra-tert-butylphthalocyanine with electron-donating ligands

2008 ◽  
Vol 12 (10) ◽  
pp. 1118-1122 ◽  
Author(s):  
Natalia Sh. Lebedeva ◽  
Elena A. Malkova ◽  
Shushanna R. Melkonyn ◽  
Mihail I. Fedorov ◽  
Sergey V. Maslennikov ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Complex Formation ◽  
Molecular Complex ◽  
Molecular Complexes ◽  
Specific Electrical Conductivity ◽  
Polymorphous Modification ◽  
Molecular Complex Formation

Topography and specific electrical conductivity of films of molecular complexes of zinc(II)tetra-tert-butylphthalocyanine ( Zn (t- Bu )4 Pc ) with electron-donating ligands and films of pure α-polymorphous modification of zinc(II)tetra-tert-butylphthalocyanine have been studied. It has been found that the specific electrical conductivity increases from 30 to 3.5 × 105 times upon molecular complex formation of Zn (t- Bu )4 Pc with ligands.

Effects of solvents on molecular complex formation equilibriums. Use of nonpolar analogs for polar solutes

1971 ◽  
Vol 75 (15) ◽  
pp. 2413-2415 ◽  
Author(s):  
Sherril D. Christian ◽  
Kwang Ok Yeo ◽  
Edwin E. Tucker
Keyword(s):  
Complex Formation ◽  
Molecular Complex ◽  
Molecular Complex Formation ◽  
Polar Solutes

THE PROTON RESONANCE SPECTRA OF BENZYL ACETONE

1963 ◽  
Vol 41 (2) ◽  
pp. 387-392 ◽  
Author(s):  
Steven S. Danyluk
Keyword(s):  
Low Temperature ◽  
High Field ◽  
Chemical Shifts ◽  
Molecular Complexes ◽  
Coupling Constant ◽  
Proton Resonance ◽  
Trans Conformation ◽  
Rapid Rotation ◽  
Aromatic Solvents ◽  
Solvent Dependence

The proton resonance spectra of benzyl acetone (4-phenyl-2-butanone) are reported in a variety of solvents at 23 °C. A marked solvent dependence is noted for the CH3 group and the methylene protons adjacent to the keto group. The shifts to high field in aromatic solvents are interpreted in terms of a specific dipole-induced interaction with solvent molecules.The signals for the two non-equivalent pairs of methylene protons show changes in coupling constant with temperature. From this it is concluded that rapid rotation occurs about the C—C bond in the temperature range investigated with an increase in population of the trans conformation at low temperature. Significant changes in relative chemical shifts are also noted with temperature change for the two pairs of methylene protons and are attributed to the formation of weak molecular complexes in aromatic solvents.

scholarly journals Nuclear magnetic resonance investigation of cadmium 113 substituted pea and lentil lectins.

1987 ◽  
Vol 262 (12) ◽  
pp. 5616-5621 ◽  
Author(s):  
L. Bhattacharyya ◽  
P.S. Marchetti ◽  
P.D. Ellis ◽  
C.F. Brewer
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Resonance Investigation ◽  
Nuclear Magnetic Resonance Investigation ◽  
Magnetic Resonance Investigation ◽  
Nuclear Magnetic

scholarly journals Polymer Optical Waveguide Sensor Based on Fe-Amino-Triazole Complex Molecular Switches

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 195
Author(s):  
Muhammad Shaukat Khan ◽  
Hunain Farooq ◽  
Christopher Wittmund ◽  
Stephen Klimke ◽  
Roland Lachmayer ◽  
...  
Keyword(s):  
Molecular Complex ◽  
Electromagnetic Interference ◽  
Optical Power ◽  
Uv Curing ◽  
Molecular Complexes ◽  
Core Material ◽  
Absorption Bands ◽  
Electronic Temperature ◽  
Polymer Waveguide ◽  
Temperature Detection

We report on a polymer-waveguide-based temperature sensing system relying on switchable molecular complexes. The polymer waveguide cladding is fabricated using a maskless lithographic optical system and replicated onto polymer material (i.e., PMMA) using a hot embossing device. An iron-amino-triazole molecular complex material (i.e., [Fe(Htrz)2.85(NH2-trz)0.15](ClO4)2) is used to sense changes in ambient temperature. For this purpose, the core of the waveguide is filled with a mixture of core material (NOA68), and the molecular complex using doctor blading and UV curing is applied for solidification. The absorption spectrum of the molecular complex in the UV/VIS light range features two prominent absorption bands in the low-spin state. As temperature approaches room temperature, a spin-crossover transition occurs, and the molecular complex changes its color (i.e. spectral properties) from violet-pink to white. The measurement of the optical power transmitted through the waveguide as a function of temperature exhibits a memory effect with a hysteresis width of approx. 12 °C and sensitivity of 0.08 mW/°C. This enables optical rather than electronic temperature detection in environments where electromagnetic interference might influence the measurements.

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