Two Stable Phosphorus-Containing Four-Membered Ring Radical Cations with Inverse Spin Density Distributions

2014 ◽  
Vol 136 (17) ◽  
pp. 6251-6254 ◽  
Author(s):  
Yuanting Su ◽  
Xin Zheng ◽  
Xingyong Wang ◽  
Xuan Zhang ◽  
Yunxia Sui ◽  
...  
Keyword(s):  
Spin Density ◽  
Radical Cations ◽  
Membered Ring ◽  
Density Distributions ◽  
Phosphorus Containing

Two phosphaalkene radical cations with inverse spin density distributions

2015 ◽  
Vol 44 (34) ◽  
pp. 15099-15102 ◽  
Author(s):  
Xiaobo Pan ◽  
Xingyong Wang ◽  
Zaichao Zhang ◽  
Xinping Wang
Keyword(s):  
Spin Density ◽  
Radical Cations ◽  
Density Distributions ◽  
Weakly Coordinating ◽  
Weakly Coordinating Anion

Two phosphaalkene radical cations have been made by using a weakly coordinating anion, and they exhibit inverse spin density distributions.

Computational Investigation of the Asymmetry in Photosynthetic Reaction Center Models from First Principles

2020 ◽  
Author(s):  
Denis Artiukhin ◽  
Patrick Eschenbach ◽  
Johannes Neugebauer
Keyword(s):  
Spin Density ◽  
Reaction Center ◽  
Density Functional ◽  
Photosynthetic Reaction Center ◽  
Chem Phys ◽  
Molecular Structures ◽  
Error Characteristic ◽  
Molecular Systems ◽  
Density Distributions ◽  
The Asymmetry

We present a computational analysis of the asymmetry in reaction center models of photosystem I, photosystem II, and bacteria from <i>Synechococcus elongatus</i>, <i>Thermococcus vulcanus</i>, and <i>Rhodobacter sphaeroides</i>, respectively. The recently developed FDE-diab methodology [J. Chem. Phys., 148 (2018), 214104] allowed us to effectively avoid the spin-density overdelocalization error characteristic for standard Kohn–Sham Density Functional Theory and to reliably calculate spin-density distributions and electronic couplings for a number of molecular systems ranging from dimeric models in vacuum to large protein including up to about 2000 atoms. The calculated spin densities showed a good agreement with available experimental results and were used to validate reaction center models reported in the literature. We demonstrated that the applied theoretical approach is very sensitive to changes in molecular structures and relative orientation of molecules. This makes FDE-diab a valuable tool for electronic structure calculations of large photosynthetic models effectively complementing the existing experimental techniques.

A Combined ab initio and Density Functional Study of the Electronic Structure of Thymine and 2-Thiothymine Radicals

2003 ◽  
Vol 68 (12) ◽  
pp. 2322-2334 ◽  
Author(s):  
Robert Vianello ◽  
Zvonimir B. Maksić
Keyword(s):  
Ab Initio ◽  
Spin Density ◽  
Density Functional ◽  
Radical Cations ◽  
Functional Study ◽  
Theory Approach ◽  
Functional Theory ◽  
Adiabatic Ionization Potential ◽  
Highest Occupied Molecular Orbital ◽  
Positively Charged

The electronic and energetic properties of thymine (1) and 2-thiothymine (2) and their neutral and positively charged radicals are considered by a combined ab initio and density functional theory approach. It is conclusively shown that ionization of 1 and 2 greatly facilitates deprotonation of the formed radical cations thus making the proton transfer between charged and neutral precursor species thermodynamically favourable. The adiabatic ionization potential of 1 and 2 are analysed. It appears that ADIP(1) is larger than ADIP(2) by 10 kcal/mol, because of greater stability of the highest occupied molecular orbital (HOMO) of the former. It is also shown beyond any doubt that the spin density in neutral and cationic radical of 2 is almost exclusively placed on the σ-3p AO of sulfur implying that these two systems represent rather rare sigma-radicals. In contrast, the spin density of radicals of 1 is distributed over their π-network.

Conformational properties of cyclic pentaalkoxy phosphoranes: Apical-equatorial attachment and nonchair conformation of the phosphorus-containing six-membered ring

1991 ◽  
Vol 2 (1) ◽  
pp. 177-185 ◽  
Author(s):  
Jaehoon Yu ◽  
Alan E. Sopchik ◽  
Atta M. Arif ◽  
Wesley G. Bentrude ◽  
G.-V. Roeschenthaler
Keyword(s):  
Membered Ring ◽  
Phosphorus Containing ◽  
Conformational Properties

ChemInform Abstract: CONFORMATIONS OF FOUR-MEMBERED RING HYDRAZINES AND HYDRAZINE RADICAL CATIONS

1978 ◽  
Vol 9 (33) ◽  
Author(s):  
S. F. NELSEN ◽  
V. E. PEACOCK ◽  
G. R. WEISMAN ◽  
M. E. LANDIS ◽  
J. A. SPENCER
Keyword(s):  
Radical Cations ◽  
Membered Ring

Density functional theory study on the structural, reactivity, and electronic properties of all mono-, di-, tri-, tetra-, and penta-fluoroanilines as monomers for conducting polymers

2012 ◽  
Vol 90 (10) ◽  
pp. 902-914 ◽  
Author(s):  
Hossein Shirani Il Beigi
Keyword(s):  
Density Functional Theory ◽  
Conducting Polymers ◽  
Structural Properties ◽  
Density Functional ◽  
Dipole Moments ◽  
Radical Cations ◽  
The Other ◽  
Functional Theory ◽  
Density Distributions ◽  
Electric Polarizabilities

Electrical and structural properties of mono-, di-, tri-, tetra-, and penta-fluoroanilines as candidate monomers for new conducting polymers have been investigated using hybrid density functional theory (B3LYP/6–311+G**) based methods. The effects of the number and position of the fluorine atoms on the electrical and structural properties of fluoroanilines and their radical cations have also been investigated. The values of the vibrational frequencies, charge and spin-density distributions, ionization potentials, dipole moments, electric polarizabilities, HOMO-LUMO gaps, and the NICS values of these compounds have been calculated and analyzed as well. The results showed that the double bonds in 2-fluoroaniline and 2,5-difluoroaniline are more delocalized compared with other fluoroanilines; therefore, these molecules have the most aptitude for the electropolymerization reactions. The frequency analysis showed that the electrochemical stability of 2-fluoroaniline is greater than the other fluoroanilines. Also, this molecule possesses the largest NICS value compared to the other fluoroanilines. Consequently, 2-fluoroaniline has the largest ring current and the highest conductivity among all other monomers. Based on the results obtained, 2-fluoroaniline and 2,5-difluoroaniline are the best candidate monomers among all fluoroanilines for the synthesis of corresponding conducting polymers.

Synthese von vier- und achtgliedrigen Heterocyclen, die Schwefel, Stickstoff und Phosphor enthalten, und die Röntgenstrukturanalyse eines phosphorhaltigen achtgliedrigen SN-Ringes / Synthesis of Four- and Eight-Membered Heterocycles Containing Sulfur, Nitrogen and Phosphorus and the X-ray Structure of a Phosphorus-Containing Eight-Membered SN-Ring

1980 ◽  
Vol 35 (9) ◽  
pp. 1130-1136 ◽  
Author(s):  
Herbert W. Roesky ◽  
Sushil K. Mehrotra ◽  
Christoph Platte ◽  
Djamrnschid Amirzadeh-Asl ◽  
Bernhard Roth
Keyword(s):  
Tertiary Amine ◽  
Phosphorus Atom ◽  
Mass Spectra ◽  
Phosphorus Pentachloride ◽  
Membered Ring ◽  
Phosphonium Salts ◽  
Nitrogen And Phosphorus ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Phosphorus Containing

Eight-membered rings of the composition [SO2(NR)2PR′]2 3a-d with R = CH3, C2H5, and R′ = CH3, C6H5, were prepared from substituted sulfamides and dichlorophosphanes in the presence of a tertiary amine. These molecules were characterized on the basis of 1H and 31P NMR investigations and of mass spectra. 3 a reacts with phosphorus pentachloride to yield the spirocyclic derivative 4 with the phosphorus atom in the center of two four-membered rings. Methyliodide reacts with 3 a and 3 b under opening of the eight- membered ring and formation of phosphonium salts. The structure of 3 b is discussed in detail. 8b crystallizes in the orthorhombic space group Pna 21 with a = 12.60(0), b = 13.27(1), c = 12.62(4) Å.

Sign in / Sign up

Export Citation Format

Share Document