Redox-Active Heteroacene Chromophores Derived from a Non-Linear Aromatic Diimide

2019 ◽  
Author(s):  
Stella Luo ◽  
Kellie Stellmach ◽  
Stella Ikuzwe ◽  
Dennis Cao
Keyword(s):  
Density Functional Theory ◽  
Nucleophilic Substitution ◽  
Building Block ◽  
Density Functional ◽  
Organic Materials ◽  
Density Functional Theory Calculations ◽  
Differential Pulse ◽  
Fine Tuning ◽  
Functional Theory ◽  
Redox Active

<div>This work describes a three-step chromatography-free protocol for the synthesis of a novel organic materials</div><div>building block, dichlorinated mellophanic diimide (MDI), that is shown to undergo nucleophilic substitution</div><div>with a variety of ortho disubstituted benzenes to yield a series of chromophores. Furthermore, 1,2,4,5-</div><div>tetrasubstituted benzenes can be used to synthesize tetraimide heteropentacene derivatives endcapped by</div><div>MDI motifs. The fine-tuning effects of heteroatom identity were investigated by UV-Vis and fluorescence</div><div>spectroscopy, cyclic and differential pulse voltammetries, and density functional theory calculations. Oxidation</div><div>of diamino MDI derivatives yields di- and tetraimide functionalized azaacenes with significantly lowered LUMO</div><div>levels (down to –4.49 eV), narrowed bandgaps (down to 1.81 eV), and high molar absorptivities (up to 84,000</div><div>M<sup>–1</sup> cm<sup>–1</sup>).</div>

Redox-Active Heteroacene Chromophores Derived from a Non-Linear Aromatic Diimide

2019 ◽  
Author(s):  
Stella Luo ◽  
Kellie Stellmach ◽  
Stella Ikuzwe ◽  
Dennis Cao
Keyword(s):  
Density Functional Theory ◽  
Nucleophilic Substitution ◽  
Building Block ◽  
Density Functional ◽  
Organic Materials ◽  
Density Functional Theory Calculations ◽  
Differential Pulse ◽  
Fine Tuning ◽  
Functional Theory ◽  
Redox Active

<div>This work describes a three-step chromatography-free protocol for the synthesis of a novel organic materials</div><div>building block, dichlorinated mellophanic diimide (MDI), that is shown to undergo nucleophilic substitution</div><div>with a variety of ortho disubstituted benzenes to yield a series of chromophores. Furthermore, 1,2,4,5-</div><div>tetrasubstituted benzenes can be used to synthesize tetraimide heteropentacene derivatives endcapped by</div><div>MDI motifs. The fine-tuning effects of heteroatom identity were investigated by UV-Vis and fluorescence</div><div>spectroscopy, cyclic and differential pulse voltammetries, and density functional theory calculations. Oxidation</div><div>of diamino MDI derivatives yields di- and tetraimide functionalized azaacenes with significantly lowered LUMO</div><div>levels (down to –4.49 eV), narrowed bandgaps (down to 1.81 eV), and high molar absorptivities (up to 84,000</div><div>M<sup>–1</sup> cm<sup>–1</sup>).</div>

Nucleophilic Substitution Reactions of Cyclic Thiosulfinates Are Accelerated by Hyperconjugative Interactions

2019 ◽  
Author(s):  
Daniel Donnelly ◽  
Jeffrey Agar ◽  
Steven Lopez
Keyword(s):  
Density Functional Theory ◽  
Nucleophilic Substitution ◽  
Strain Energy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Free Energies ◽  
Substitution Reactions ◽  
Functional Theory ◽  
Nucleophilic Substitution Reactions

Strain energy has been shown to promote the nucleophilic substitution reactions of cyclic disulfides, the reactivities of cyclic thiosulfinate nucleophilic substitution is unexplored. We used density functional theory calculations [M06-2X/6-311++G(d,p)] to determine the activation and reaction free energies for the reactions of 3—10-membered cyclic thiosulfinates and cyclic disulfides with methyl thiolate.

Nucleophilic Substitution Reactions of Cyclic Thiosulfinates Are Accelerated by Hyperconjugative Interactions

2019 ◽  
Author(s):  
Daniel Donnelly ◽  
Jeffrey Agar ◽  
Steven Lopez
Keyword(s):  
Density Functional Theory ◽  
Nucleophilic Substitution ◽  
Strain Energy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Free Energies ◽  
Substitution Reactions ◽  
Functional Theory ◽  
Nucleophilic Substitution Reactions

Strain energy has been shown to promote the nucleophilic substitution reactions of cyclic disulfides, the reactivities of cyclic thiosulfinate nucleophilic substitution is unexplored. We used density functional theory calculations [M06-2X/6-311++G(d,p)] to determine the activation and reaction free energies for the reactions of 3—10-membered cyclic thiosulfinates and cyclic disulfides with methyl thiolate.

Is a Non-Transition Element Nitride Ferromagnet Ever Achievable? Indication of the N-N Pairing Instability

2006 ◽  
Vol 71 (11-12) ◽  
pp. 1525-1531 ◽  
Author(s):  
Wojciech Grochala
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Transition Element ◽  
Density Functional Theory Calculations ◽  
Functional Theory

The enthalpy of four polymorphs of CaN has been scrutinized at 0 and 100 GPa using density functional theory calculations. It is shown that structures of diamagnetic calcium diazenide (Ca2N2) are preferred over the cubic ferromagnetic polymorph (CaN) postulated before, both at 0 and 100 GPa.

scholarly journals Tensor-structured algorithm for reduced-order scaling large-scale Kohn–Sham density functional theory calculations

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chih-Chuen Lin ◽  
Phani Motamarri ◽  
Vikram Gavini
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Large Scale ◽  
Density Functional Theory Calculations ◽  
System Size ◽  
Real Space ◽  
Functional Theory ◽  
Reduced Order ◽  
Separable Approximation ◽  
Tensor Basis

AbstractWe present a tensor-structured algorithm for efficient large-scale density functional theory (DFT) calculations by constructing a Tucker tensor basis that is adapted to the Kohn–Sham Hamiltonian and localized in real-space. The proposed approach uses an additive separable approximation to the Kohn–Sham Hamiltonian and an L1 localization technique to generate the 1-D localized functions that constitute the Tucker tensor basis. Numerical results show that the resulting Tucker tensor basis exhibits exponential convergence in the ground-state energy with increasing Tucker rank. Further, the proposed tensor-structured algorithm demonstrated sub-quadratic scaling with system-size for both systems with and without a gap, and involving many thousands of atoms. This reduced-order scaling has also resulted in the proposed approach outperforming plane-wave DFT implementation for systems beyond 2000 electrons.

Sign in / Sign up

Export Citation Format

Share Document