scholarly journals Capture of Fullerenes in Cages and Rings by Forming Metal-π Bond Arene Interactions

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3424
Author(s):  
Citlalli Rios ◽  
Bertha Molina ◽  
Roberto Salcedo
Keyword(s):  
Organic Molecules ◽  
Theoretical Study ◽  
Molecular Orbitals ◽  
Frontier Molecular Orbitals ◽  
Metallic Atom ◽  
The Subject ◽  
Low Solubility

Nowadays, the task of the selectively capture of fullerene molecules from soot is the subject of several studies. The low solubility of fullerenes represents a drawback when the goal is to purify them and to carry out chemical procedures where they participate. There are different molecules that can act as a kind of cocoon, giving shelter to the fullerene cages in such a way that they can be included in a solution or can be extracted from a mix. In this work, a theoretical study of some known and new proposed organic molecules of this kind is presented. In all cases, the interaction occurs with the help of a metallic atom or ion which plays the role of a bridge, providing a place for a metallocene like interaction to occur. The thermodynamic arguments favoring the formation of this adduct species are addressed as well as the nature of the bond by means QTAIM parameters and frontier molecular orbitals analysis.

scholarly journals Polar molecules catalyze CO insertion into metal-alkyl bonds through the displacement of an agostic C-H bond

2019 ◽  
Vol 116 (9) ◽  
pp. 3419-3424
Author(s):  
Tian Zhou ◽  
Santanu Malakar ◽  
Steven L. Webb ◽  
Karsten Krogh-Jespersen ◽  
Alan S. Goldman
Keyword(s):  
Transition Metal Complexes ◽  
Density Functional ◽  
Organic Molecules ◽  
Polar Molecules ◽  
Functional Theory ◽  
Bond Forming ◽  
Co Insertion ◽  
The Subject ◽  
Kinetics Of

The insertion of CO into metal-alkyl bonds is the key C-C bond-forming step in many of the most important organic reactions catalyzed by transition metal complexes. Polar organic molecules (e.g., tetrahydrofuran) have long been known to promote CO insertion reactions, but the mechanism of their action has been the subject of unresolved speculation for over five decades. Comprehensive computational studies [density functional theory (DFT)] on the prototypical system Mn(CO)5(arylmethyl) reveal that the polar molecules do not promote the actual alkyl migration step. Instead, CO insertion (i.e. alkyl migration) occurs rapidly and reversibly to give an acyl complex with a sigma-bound (agostic) C-H bond that is not easily displaced by typical ligands (e.g. phosphines or CO). The agostic C-H bond is displaced much more readily, however, by the polar promoter molecules, even though such species bind only weakly to the metal center and are themselves then easily displaced; the facile kinetics of this process are attributable to a hydrogen bonding-like interaction between the agostic C-H bond and the polar promoter. The role of the promoter is to thereby catalyze isomerization of the agostic product of CO insertion to give an η2-C,O-bound acyl product that is more easily trapped than the agostic species. This ability of such promoters to displace a strongly sigma-bound C-H bond and to subsequently undergo facile displacement themselves is without reported precedent, and could have implications for catalytic reactions beyond carbonylation.

Theoretical study of the physisorption of organic molecules on conjugated microporous polymers: the critical role of skeleton structures on binding strength

RSC Advances ◽  
2016 ◽  
Vol 6 (60) ◽  
pp. 54841-54847 ◽  
Author(s):  
Wen-Jie Fan ◽  
Gui-Juan Yang ◽  
Jian-Wei Chi ◽  
You Yu ◽  
Da-Zhi Tan
Keyword(s):  
Binding Energy ◽  
Organic Molecules ◽  
Theoretical Study ◽  
Critical Role ◽  
Binding Strength ◽  
Microporous Polymers ◽  
Substituent Group ◽  
Conjugated Microporous Polymers

By enlarging the size (area) in the linker or adding substituent group in the node, the binding energy between CMPs and adsorbates will increase significantly, which demonstrates the critical role of skeleton structures on binding strength.

Hammett correlations as test of mechanism of CO-induced disulfide elimination from dinitrosyl iron complexes

2014 ◽  
Vol 5 (10) ◽  
pp. 3795-3802 ◽  
Author(s):  
Randara Pulukkody ◽  
Samuel J. Kyran ◽  
Michael J. Drummond ◽  
Chung-Hung Hsieh ◽  
Donald J. Darensbourg ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Iron Complexes ◽  
Reductive Elimination ◽  
Molecular Orbitals ◽  
Dinitrosyl Iron Complexes ◽  
Frontier Molecular Orbitals ◽  
Dinitrosyl Iron

The use of Hammett correlations provide experimental evidence for an unusual role of the frontier molecular orbitals of an iron dinitrosyl unit in CO induced reductive elimination of disulfide.

scholarly journals New Perspectives on the Role of Frontier Molecular Orbitals in the Study of Chemical Reactivity: A Review

2016 ◽  
Vol 8 (2) ◽  
pp. 425-453 ◽  
Author(s):  
Douglas Henrique Pereira ◽  
Felipe A. La Porta ◽  
Regis Tadeu Santiago ◽  
Danielle R. Garcia ◽  
Teodorico C. Ramalho
Keyword(s):  
Chemical Reactivity ◽  
Molecular Orbitals ◽  
Frontier Molecular Orbitals

Top-Down Processing and Visual Reorientation Illusions in a Virtual Reality Environment

2004 ◽  
Vol 63 (3) ◽  
pp. 143-149 ◽  
Author(s):  
Fred W. Mast ◽  
Charles M. Oman
Keyword(s):  
Virtual Reality ◽  
Visual Processing ◽  
Line Length ◽  
Perceptual Cues ◽  
Virtual Reality Environment ◽  
Top Down ◽  
Test Conditions ◽  
The Subject ◽  
Processing Mechanisms

The role of top-down processing on the horizontal-vertical line length illusion was examined by means of an ambiguous room with dual visual verticals. In one of the test conditions, the subjects were cued to one of the two verticals and were instructed to cognitively reassign the apparent vertical to the cued orientation. When they have mentally adjusted their perception, two lines in a plus sign configuration appeared and the subjects had to evaluate which line was longer. The results showed that the line length appeared longer when it was aligned with the direction of the vertical currently perceived by the subject. This study provides a demonstration that top-down processing influences lower level visual processing mechanisms. In another test condition, the subjects had all perceptual cues available and the influence was even stronger.

The future role of the psychiatrist in Europe – a UEMS perspective

2014 ◽  
Vol 11 (01) ◽  
pp. 35-42
Author(s):  
M. Hermans
Keyword(s):  
Mental Health ◽  
Mental Health Professionals ◽  
Health Professionals ◽  
General Interest ◽  
Future Role ◽  
Personal Opinion ◽  
The Future ◽  
The Subject ◽  
The Many

SummaryThe author presents his personal opinion inviting to discussion on the possible future role of psychiatrists. His view is based upon the many contacts with psychiatrists all over Europe, academicians and everyday professionals, as well as the familiarity with the literature. The list of papers referred to is based upon (1) the general interest concerning the subject when representing ideas also worded elsewhere, (2) the accessibility to psychiatrists and mental health professionals in Germany, (3) being costless downloadable for non-subscribers and (4) for some geographic aspects (e.g. Belgium, Spain, Sweden) and the latest scientific issues, addressing some authors directly.

Alignment

2016 ◽  
pp. 33-50
Author(s):  
Pier Giuseppe Rossi
Keyword(s):  
Teaching And Learning ◽  
Enactive Approach ◽  
The World ◽  
Strategic Role ◽  
Education Today ◽  
Current Context ◽  
The Subject

The subject of alignment is not new to the world of education. Today however, it has come to mean different things and to have a heuristic value in education according to research in different areas, not least for neuroscience, and to attention to skills and to the alternation framework.This paper, after looking at the classic references that already attributed an important role to alignment in education processes, looks at the strategic role of alignment in the current context, outlining the shared construction processes and focusing on some of the ways in which this is put into effect.Alignment is part of a participatory, enactive approach that gives a central role to the interaction between teaching and learning, avoiding the limits of behaviourism, which has a greater bias towards teaching, and cognitivism/constructivism, which focus their attention on learning and in any case, on that which separates a teacher preparing the environment and a student working in it.

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