Molecular orbital ordering in titania and the associated semiconducting behavior

Here, we report an exquisite strategy that the B12 enzymes exploit to manipulate the reactivity of their radical intermediate (Adenosyl radical). Based on the quantum-mechanic calculations, these enzymes utilize a little known long-ranged through space quantum Coulombic effect (QCE). The QCE causes the radical to acquire an electronic structure that contradicts the Aufbau Principle: The singly-occupied molecular orbital (SOMO) is no longer the highest-occupied molecular orbital (HOMO) and the radical is unable to react with neighbouring substrates. The dynamic nature of the enzyme and its structure is expected to be such that the reactivity of the radical is not restored until it is moved into close proximity of the target substrate. We found that the hydrogen bonding interaction between the nearby conserved glutamate residue and the ribose ring of Adenosyl radical plays a crucial role in manipulating the orbital ordering

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Radical Enzymes Control the Chemistry of Their Highly Reactive Intermediates Using the Quantum Coulombic Effect

10.26434/chemrxiv.12839177 ◽

2020 ◽

Author(s):

Hossein Khalilian ◽

Gino A. DiLabio

Keyword(s):

Hydrogen Bonding ◽

Molecular Orbital ◽

Reactive Intermediates ◽

Hydrogen Bonding Interaction ◽

Orbital Ordering ◽

Dynamic Nature ◽

Radical Intermediate ◽

Highest Occupied Molecular Orbital ◽

Bonding Interaction ◽

Close Proximity

Here, we report an exquisite strategy that the B12 enzymes exploit to manipulate the reactivity of their radical intermediate (Adenosyl radical). Based on the quantum-mechanic calculations, these enzymes utilize a little known long-ranged through space quantum Coulombic effect (QCE). The QCE causes the radical to acquire an electronic structure that contradicts the Aufbau Principle: The singly-occupied molecular orbital (SOMO) is no longer the highest-occupied molecular orbital (HOMO) and the radical is unable to react with neighbouring substrates. The dynamic nature of the enzyme and its structure is expected to be such that the reactivity of the radical is not restored until it is moved into close proximity of the target substrate. We found that the hydrogen bonding interaction between the nearby conserved glutamate residue and the ribose ring of Adenosyl radical plays a crucial role in manipulating the orbital ordering

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Unusual Molecular Orbital Ordering in Molybdenum−Ruthenium Heterometallic Porphyrin Dimers: Structural and Magnetic Evidence

Journal of the American Chemical Society ◽

10.1021/ja980233e ◽

1998 ◽

Vol 120 (31) ◽

pp. 7999-8000 ◽

Cited By ~ 13

Author(s):

James P. Collman ◽

Steven T. Harford ◽

Pascale Maldivi ◽

Jean-Claude Marchon

Keyword(s):

Molecular Orbital ◽

Orbital Ordering ◽

Porphyrin Dimers

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The role of frontier molecular orbital ordering on electronic communication in porphyrin arrays

Chemical Physics Letters ◽

10.1016/s0009-2614(01)01457-9 ◽

2002 ◽

Vol 353 (1-2) ◽

pp. 111-118 ◽

Cited By ~ 16

Author(s):

Hui-Hsu (Gavin) Tsai ◽

M.Cather Simpson

Keyword(s):

Molecular Orbital ◽

Electronic Communication ◽

Frontier Molecular Orbital ◽

Orbital Ordering

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Adducts of oxovanadium(IV) dithiocarbamates

Canadian Journal of Chemistry ◽

10.1139/v69-706 ◽

1969 ◽

Vol 47 (22) ◽

pp. 4283-4286 ◽

Cited By ~ 16

Author(s):

B. Jack McCormick

Keyword(s):

Dimethyl Sulfoxide ◽

Molecular Orbital ◽

Spectral Properties ◽

Orbital Ordering ◽

Mild Conditions ◽

Spectral Evidence

Pyridine and 4-methylpyridine adducts of oxovanadium(IV) dithiocarbamates have been isolated and characterized as solids. It has been shown that the addenda can be removed under mild conditions with concomitant regeneration of the parent dithiocarbamate (DTC) complexes. Attempts to isolate dimethyl-sulfoxide adducts have not been successful, although spectral evidence suggests that adducts are formed in solution. A qualitative rationalization of the molecular orbital ordering and electronic spectral properties of the adducts is presented.

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