Organic ions in the gas phase. XXVII. Long-range intramolecular interactions in 4-n-alkyl trimellitic esters

1973 ◽  
Vol 95 (18) ◽  
pp. 6056-6067 ◽  
Author(s):  
Seymour. Meyerson ◽  
Imre. Puskas ◽  
Ellis K. Fields
Keyword(s):  
Gas Phase ◽  
Long Range ◽  
Intramolecular Interactions ◽  
Organic Ions

ChemInform Abstract: ORGANIC IONS IN THE GAS PHASE PART 27, LONG-RANGE INTRAMOLECULAR INTERACTIONS IN 4-N-ALKYL TRIMELLITIC ESTERS

1973 ◽  
Vol 4 (45) ◽  
pp. no-no
Author(s):  
SEYMOUR MEYERSON ◽  
IMRE PUSKAS ◽  
ELLIS K. FIELDS
Keyword(s):  
Gas Phase ◽  
Long Range ◽  
Intramolecular Interactions ◽  
Organic Ions

scholarly journals Imaging and energetics of single SSB-ssDNA molecules reveal intramolecular condensation and insight into RecOR function

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Jason C Bell ◽  
Bian Liu ◽  
Stephen C Kowalczykowski
Keyword(s):  
Long Range ◽  
Single Molecule ◽  
Magnetic Tweezers ◽  
Intramolecular Interactions ◽  
Ssdna Binding ◽  
Ssdna Binding Protein ◽  
Intramolecular Condensation ◽  
Nucleoprotein Complexes ◽  
Ssdna Binding Proteins ◽  
Dna Maintenance

Escherichia coli single-stranded DNA (ssDNA) binding protein (SSB) is the defining bacterial member of ssDNA binding proteins essential for DNA maintenance. SSB binds ssDNA with a variable footprint of ∼30–70 nucleotides, reflecting partial or full wrapping of ssDNA around a tetramer of SSB. We directly imaged single molecules of SSB-coated ssDNA using total internal reflection fluorescence (TIRF) microscopy and observed intramolecular condensation of nucleoprotein complexes exceeding expectations based on simple wrapping transitions. We further examined this unexpected property by single-molecule force spectroscopy using magnetic tweezers. In conditions favoring complete wrapping, SSB engages in long-range reversible intramolecular interactions resulting in condensation of the SSB-ssDNA complex. RecO and RecOR, which interact with SSB, further condensed the complex. Our data support the idea that RecOR--and possibly other SSB-interacting proteins—function(s) in part to alter long-range, macroscopic interactions between or throughout nucleoprotein complexes by microscopically altering wrapping and bridging distant sites.

ChemInform Abstract: THE STRUCTURE AND REACTIVITY OF ORGANIC IONS IN GAS-PHASE RADIOLYSIS PART 8, THE C7H7(+) ION FROM TOLUENE AND ETHYLBENZENE

1974 ◽  
Vol 5 (36) ◽  
Author(s):  
NOBUO SAGI ◽  
YUKIO YAMAMOTO ◽  
KENJI NAGAOKA ◽  
SETSUO TAKAMUKU ◽  
HIROSHI SAKURAI
Keyword(s):  
Gas Phase ◽  
Organic Ions

ChemInform Abstract: Structures and Reactions of Gas-Phase Organic Ions

1986 ◽  
Vol 17 (38) ◽  
Author(s):  
M. A. BALDWIN
Keyword(s):  
Gas Phase ◽  
Organic Ions

Probing Intramolecular Interaction of Stereoisomers Using Computational Spectroscopy

2020 ◽  
Vol 73 (8) ◽  
pp. 813
Author(s):  
Feng Wang ◽  
Shawkat Islam ◽  
Frederick Backler
Keyword(s):  
Hydrogen Bonding ◽  
Binding Energy ◽  
Gas Phase ◽  
Intramolecular Interaction ◽  
Dipole Moments ◽  
Energy Difference ◽  
Binding Energies ◽  
Intramolecular Interactions ◽  
Computational Spectroscopy ◽  
Ionic States

Several model stereoisomers such as ferrocene (Fc), methoxyphenol, and furfural conformers are discussed. It was discovered that the Fc IR spectroscopic band(s) below 500cm−1 serve as fingerprints for eclipsed (splitting 17 (471–488)cm−1) and staggered Fc (splitting is ~2 (459–461)cm−1) in the gas phase. It is revealed that in the gas phase the dominance of the eclipsed Fc (D5h) at very low temperatures changes to a mixture of both eclipsed and staggered Fc when the temperature increases. However, in solvents such as CCl4, eclipsed Fc dominates at room temperature (300K) due to the additional solvation energy. Intramolecular interactions of organic model compounds such as methoxyphenols (guaiacol (GUA) and mequinol (MEQ)) and furfural, ionization energies such as the carbon 1s (core C1s), as well as valence binding energy spectra serve this purpose well. Hydrogen bonding alters the C1s binding energies of the methoxy carbon (C(7)) of anti-syn and anti-gauche conformers of GUA to 292.65 and 291.91eV, respectively. The trans and cis MEQ conformers, on the other hand, are nearly energy degenerate, whereas their dipole moments are significantly different: 2.66 Debye for cis and 0.63 Debye for trans-MEQ. Moreover, it is found that rotation around the Cring–OH and the Cring–OCH3 bonds differ in energy barrier height by ~0.50 kcal⋅mol−1. The Dyson orbital momentum profiles of the most different ionic states, 25a′ (0.35eV) and 3a′ (−0.33eV), between cis and trans-MEQ in outer valence space (which is measurable using electron momentum spectroscopy (EMS)), exhibit quantitative differences. Finally, the molecular switch from trans and cis-furfural engages with a small energy difference of 0.74 kcal mol−1, however, at the calculated C(3)(–H⋅⋅⋅O=C) site the C1s binding energy difference is 0.105eV (2.42 kcal mol−1) and the NMR chemical shift of the same carbon site is also significant; 7.58ppm from cis-furfural without hydrogen bonding.

scholarly journals Gas Phase Computational Study of Diclofenac Adsorption on Chitosan Materials

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2549
Author(s):  
Anna Kaczmarek-Kędziera
Keyword(s):  
Interaction Energy ◽  
Gas Phase ◽  
Computational Study ◽  
Intramolecular Interactions ◽  
Amino Groups ◽  
Inflammatory Drugs ◽  
Low Costs ◽  
Anti Inflammatory ◽  
Single Polymer Chain ◽  
Living Organisms

Environmental pollution with non-steroidal anti-inflammatory drugs and their metabolites exposes living organisms on their long-lasting, damaging influence. Hence, the ways of non-steroidal anti-inflammatory drugs (NSAIDs) removal from soils and wastewater is sought for. Among the potential adsorbents, biopolymers are employed for their good availability, biodegradability and low costs. The first available theoretical modeling study of the interactions of diclofenac with models of pristine chitosan and its modified chains is presented here. Supermolecular interaction energy in chitosan:drug complexes is compared with the the mutual attraction of the chitosan dimers. Supermolecular interaction energy for the chitosan-diclofenac complexes is significantly lower than the mutual interaction between two chitosan chains, suggesting that the diclofenac molecule will encounter problems when penetrating into the chitosan material. However, its surface adsorption is feasible due to a large number of hydrogen bond donors and acceptors both in biopolymer and in diclofenac. Modification of chitosan material introducing long-distanced amino groups significantly influences the intramolecular interactions within a single polymer chain, thus blocking the access of diclofenac to the biopolymer backbone. The strongest attraction between two chitosan chains with two long-distanced amino groups can exceed 120 kcal/mol, while the modified chitosan:diclofenac interaction remains of the order of 20 to 40 kcal/mol.

Additions and Corrections - Organic Ions in the Gas Phase. VII. Tropylium Ion from Benzyl Chloride and Benzyl Alcohol

1960 ◽  
Vol 82 (24) ◽  
pp. 6427-6427
Author(s):  
Seymour Meyerson ◽  
Paul Rylander ◽  
Ernest Eliel ◽  
John McCollum
Keyword(s):  
Benzyl Alcohol ◽  
Gas Phase ◽  
Benzyl Chloride ◽  
Organic Ions

scholarly journals Structure and Reactivity of Organic Ions in Gas-Phase Radiolysis. III. The Benzenonium Ions Formed by the Reactions of CH5+and C2H5+Ions from Methane witho-Xylene

1972 ◽  
Vol 45 (1) ◽  
pp. 255-258 ◽  
Author(s):  
Yukio Yamamoto ◽  
Setsuo Takamuku ◽  
Hiroshi Sakurai
Keyword(s):  
Gas Phase ◽  
Organic Ions

Organic Ions in the Gas Phase. V. C6H5+ Ion from Toluene

1957 ◽  
Vol 27 (5) ◽  
pp. 1116-1117 ◽  
Author(s):  
Paul N. Rylander ◽  
Seymour Meyerson
Keyword(s):  
Gas Phase ◽  
Organic Ions

STRUCTURE AND REACTIVITY OF ORGANIC IONS IN GAS-PHASE RADIOLYSIS. IV. THE C7H7+ION FROM CYCLOHEPTATRIENE

1973 ◽  
Vol 2 (12) ◽  
pp. 1303-1306 ◽  
Author(s):  
Setsuo Takamuku ◽  
Katsuyoshi Nakamura ◽  
Kenji Nagaoka ◽  
Hiroshi Sakurai
Keyword(s):  
Gas Phase ◽  
Organic Ions
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