A New Pathway for Activation of C - C and C - H Bonds by Transition Metals in the Gas Phase

2005 ◽  
Vol 58 (2) ◽  
pp. 82 ◽  
Author(s):  
Dongju Zhang ◽  
Ruoxi Wang ◽  
Rongxiu Zhu
Keyword(s):  
Transition Metals ◽  
Gas Phase ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Bond Activation ◽  
Level Density ◽  
Elimination Mechanism ◽  
Activation Of Hydrocarbons ◽  
High Level ◽  
H2 Elimination

C–H and C–C bond activation of hydrocarbons at metal centres are of fundamental importance in biochemistry, organometallic chemistry, and catalysis. The present work aims to search for novel mechanisms for activation of C–C and C–H bonds by transition metals in the gas phase. Using high-level density functional calculations, we systemically studied the reactions of Ti+, V+, and Fe+ with ethane, and proposed new pathways of C–C and C–H bond activation—concerted activation of C–C and C–H bonds, and 1,2-H2 elimination. These two pathways clearly differ from the general addition–elimination mechanism.

scholarly journals Density functional calculations on first‐row transition metals

1994 ◽  
Vol 101 (9) ◽  
pp. 7729-7737 ◽  
Author(s):  
Thomas V. Russo ◽  
Richard L. Martin ◽  
P. Jeffrey Hay
Keyword(s):  
Transition Metals ◽  
Density Functional Calculations ◽  
Density Functional

scholarly journals A Data-Driven Approach to the Development and Understanding of Chiroptical Sensors for Alcohols with Remote γ-Stereocenters

2021 ◽  
Author(s):  
Jordan Dotson ◽  
Eric Anslyn ◽  
Matthew Sigman
Keyword(s):  
Density Functional ◽  
Level Density ◽  
Enantiomeric Excess ◽  
Data Driven ◽  
Functional Theory ◽  
Dynamic Covalent Chemistry ◽  
Sensor Optimization ◽  
Data Driven Approach ◽  
High Level ◽  
Sensor Molecules

Dynamic covalent chemistry-based sensors have recently emerged as powerful tools to rapidly determine the enantiomeric excess of organic small molecules. While a bevy of sensors have been developed, those for flexible molecules with stereocenters remote to the functional group that binds the chiroptical sensor remain scarce. In this study, we develop an iterative, data-driven workflow to design and analyze a chiroptical sensor capable of assessing challenging acyclic γ-stereogenic alcohols. Fol-lowing sensor optimization, the mechanism of sensing was probed with a combination of computational parameterization of the sensor molecules, statistical modeling, and high-level density functional theory (DFT) calculations. These were used to elucidate the mechanism of stereochemical recognition and revealed that competing attractive non-covalent interactions (NCIs) determine the overall performance of the sensor. It is anticipated that the data-driven workflows developed herein will be generally applicable to the development and understanding of dynamic covalent and supramolecular sensors.

Sind Metalloprotonencryptanden möglich? – DFT-Studie zur Protonenaffinität von [2.2.2]-analogen Metallocryptanden / Can Metallocryptands act as Proton Cages? – DFT Study of Proton Affinity in [2.2.2]-analogousMetallocryptands Sind Metalloprotonencryptanden m¨oglich? – DFT-Studie zur Protonenaffinit¨at von [2.2.2]-analogen Metallocryptanden

2010 ◽  
Vol 65 (3) ◽  
pp. 231-s261 ◽  
Author(s):  
Ralph Puchta ◽  
Andreas Scheurer
Keyword(s):  
Coordination Chemistry ◽  
Gas Phase ◽  
Proton Affinity ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Dft Study ◽  
Proton Sponges

Based on density functional calculations (RB3LYP/LANL2DZp) the bicyclic metallocryptand [Pd3(L2)2] [(L2)3−: 1,1´ ,1´´-nitrilotris(5,5-dimethylhexane-2,4-dione trianion)] shows the same high gas-phase basicity (−257.1 kcal mol−1) as Lehn’s [2.2.2] cryptand (−254.4 kcal mol−1). This illustrates that the concept of metallotopomers adopted by Saalfrank et al. can be applied to design proton sponges as well as proton cryptands by metallosupramolecular coordination chemistry. The slightly higher gas-phase proton affinity of [Pd3(L2)2] compared to [2.2.2] can be attributed to the smaller cavity in the metallotopomer.

scholarly journals Combined FTIR Matrix Isolation and Density Functional Studies of Indole-3-Pyruvic Acid Molecule. Spectroscopic Evidence of Gas-Phase Tautomerism

2012 ◽  
Vol 2012 ◽  
pp. 1-11
Author(s):  
Luigi Bencivenni ◽  
Andrea Margonelli ◽  
Alessandro Mariani ◽  
Andrea Pieretti ◽  
Stella Nunziante Cesaro
Keyword(s):  
Vibrational Spectrum ◽  
Gas Phase ◽  
Pyruvic Acid ◽  
Density Functional Calculations ◽  
Spectroscopic Data ◽  
Density Functional ◽  
Matrix Isolation ◽  
Vapour Phase ◽  
Acid Molecule ◽  
Functional Studies

The vibrational spectrum of matrix-isolated indole-3-pyruvic acid has been studied aiming to obtain information about the structures of the stable vapour-phase forms of the molecule. Together with results from theoretical density functional calculations, the spectroscopic data enable to undertake an attribution for most of the observed bands. The FTIR spectrum of crystalline indole-3-pyruvic acid has been compared with that of matrix isolation study.

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