scholarly journals Intracluster proton transfer in protonated benzonitrile–(H2O)n≤6 nanoclusters: hydrated hydronium core for n ≥ 2

2019 ◽  
Vol 21 (45) ◽  
pp. 25226-25246 ◽  
Author(s):  
Kuntal Chatterjee ◽  
Otto Dopfer
Keyword(s):  
Density Functional Theory ◽  
Infrared Spectroscopy ◽  
Proton Transfer ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Dopant Molecule

Infrared spectroscopy and density functional theory calculations of protonated benzonitrile–(H2O)n clusters reveal proton transfer to solvent for n ≥ 2 and the drastic effects of the aromatic dopant molecule on the network of H+(H2O)n+1.

scholarly journals Microhydration of PAH+ cations: evolution of hydration network in naphthalene+-(H2O)n clusters (n ≤ 5)

2018 ◽  
Vol 9 (8) ◽  
pp. 2301-2318 ◽  
Author(s):  
Kuntal Chatterjee ◽  
Otto Dopfer
Keyword(s):  
Density Functional Theory ◽  
Infrared Spectroscopy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Size Selected Clusters

The evolution of the microhydration network around a prototypical PAH+ cation is determined by infrared spectroscopy of size-selected clusters and density functional theory calculations.

scholarly journals Spectroscopic identification of fragment ions of DNA/RNA building blocks: the case of pyrimidine

2020 ◽  
Vol 22 (30) ◽  
pp. 17275-17290
Author(s):  
Kuntal Chatterjee ◽  
Otto Dopfer
Keyword(s):  
Density Functional Theory ◽  
Infrared Spectroscopy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Functional Theory ◽  
Fragment Ions ◽  
Sequential Loss ◽  
Spectroscopic Identification

The structure of the predominant fragments of the fundamental pyrimidine cation arising from sequential loss of HCN are identified by infrared spectroscopy of tagged ions and dispersion-corrected density functional theory calculations.

scholarly journals Microhydration of protonated biomolecular building blocks: protonated pyrimidine

2020 ◽  
Vol 22 (23) ◽  
pp. 13092-13107
Author(s):  
Kuntal Chatterjee ◽  
Otto Dopfer
Keyword(s):  
Density Functional Theory ◽  
Infrared Spectroscopy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Protonation Site ◽  
Functional Theory

The protonation site and evolution of the hydration network in microsolvated protonated pyrimidine clusters, H+Pym–(H2O)n with n = 1–4, has been explored by infrared spectroscopy and density functional theory calculations.

scholarly journals Influence of Varying Functionalization on the Peroxidase Activity of Nickel(II)–Pyridine Macrocycle Catalysts: Mechanistic Insights from Density Functional Theory

Computation ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 52
Author(s):  
Jerwin Jay E. Taping ◽  
Junie B. Billones ◽  
Voltaire G. Organo
Keyword(s):  
Density Functional Theory ◽  
Proton Transfer ◽  
Density Functional ◽  
Experimental Studies ◽  
Density Functional Theory Calculations ◽  
Catalytic Performance ◽  
Stoichiometric Ratio ◽  
Functional Theory ◽  
Pendant Arm ◽  
Spin Singlet

Nickel(II) complexes of mono-functionalized pyridine-tetraazamacrocycles (PyMACs) are a new class of catalysts that possess promising activity similar to biological peroxidases. Experimental studies with ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), substrate) and H2O2 (oxidant) proposed that hydrogen-bonding and proton-transfer reactions facilitated by their pendant arm were responsible for their catalytic activity. In this work, density functional theory calculations were performed to unravel the influence of pendant arm functionalization on the catalytic performance of Ni(II)–PyMACs. Generated frontier orbitals suggested that Ni(II)–PyMACs activate H2O2 by satisfying two requirements: (1) the deprotonation of H2O2 to form the highly nucleophilic HOO−, and (2) the generation of low-spin, singlet state Ni(II)–PyMACs to allow the binding of HOO−. COSMO solvation-based energies revealed that the O–O Ni(II)–hydroperoxo bond, regardless of pendant arm type, ruptures favorably via heterolysis to produce high-spin (S = 1) [(L)Ni3+–O·]2+ and HO−. Aqueous solvation was found crucial in the stabilization of charged species, thereby favoring the heterolytic process over homolytic. The redox reaction of [(L)Ni3+–O·]2+ with ABTS obeyed a 1:2 stoichiometric ratio, followed by proton transfer to produce the final intermediate. The regeneration of Ni(II)–PyMACs at the final step involved the liberation of HO−, which was highly favorable when protons were readily available or when the pKa of the pendant arm was low.

scholarly journals Caryolene-forming carbocation rearrangements

2013 ◽  
Vol 9 ◽  
pp. 323-331 ◽  
Author(s):  
Quynh Nhu N Nguyen ◽  
Dean J Tantillo
Keyword(s):  
Density Functional Theory ◽  
Proton Transfer ◽  
Energy Barrier ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Intramolecular Proton Transfer ◽  
The Other ◽  
Orbital Symmetry ◽  
Functional Theory ◽  
Biosynthetic Precursor

Density functional theory calculations on mechanisms of the formation of caryolene, a putative biosynthetic precursor to caryol-1(11)-en-10-ol, reveal two mechanisms for caryolene formation: one involves a base-catalyzed deprotonation/reprotonation sequence and tertiary carbocation minimum, whereas the other (with a higher energy barrier) involves intramolecular proton transfer and the generation of a secondary carbocation minimum and a hydrogen-bridged minimum. Both mechanisms are predicted to involve concerted suprafacial/suprafacial [2 + 2] cycloadditions, whose asynchronicity allows them to avoid the constraints of orbital symmetry.

An octacoordinated Nb atom in the NbAl8H8+ cluster

2021 ◽  
Author(s):  
Piero Ferrari ◽  
Hung Tan Pham ◽  
Jan Vanbuel ◽  
Andre Fielicke ◽  
Minh T. Nguyen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Density Functional Theory ◽  
Infrared Spectroscopy ◽  
Density Functional ◽  
Molecular Beam ◽  
Density Functional Theory Calculations ◽  
High Symmetry ◽  
Functional Theory

The NbAl8H8+ cluster was formed in a molecular beam and characterized by mass spectrometry and infrared spectroscopy. Density functional theory calculations showed that its lowest-energy isomer is a high symmetry...

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