A stable open-shell redox active ditopic ligand

2016 ◽  
Vol 45 (13) ◽  
pp. 5460-5463 ◽  
Author(s):  
N. M. Bonanno ◽  
A. J. Lough ◽  
K. E. Prosser ◽  
C. J. Walsby ◽  
P. K. Poddutoori ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Open Shell ◽  
Redox Active ◽  
Ditopic Ligand

Herein we describe the synthesis, structure and electronic properties of an unusual redox-active ditopic ligand with a stable open-shell configuration.

Changes in Electronic Properties of Polymeric One-Dimensional {[M(CN)2]−}n(M = Au, Ag) Chains Due to Neighboring Closed-Shell Zn(II) or Open-Shell Cu(II) Ions

2011 ◽  
Vol 50 (1) ◽  
pp. 231-237 ◽  
Author(s):  
François Baril-Robert ◽  
Xiaobo Li ◽  
Michael J. Katz ◽  
Andrew R. Geisheimer ◽  
Daniel B. Leznoff ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Closed Shell ◽  
Open Shell ◽  
One Dimensional

scholarly journals Ligand-Mediated Spin State Changes in a Cobalt-Dipyrrin-Bisphenol Complex

2020 ◽  
Author(s):  
Nicolaas P. van Leest ◽  
Wowa Stroek ◽  
Maxime A. Siegler ◽  
Jarl Ivar van der Vlugt ◽  
Bas de Bruin
Keyword(s):  
Cobalt Complex ◽  
Closed Shell ◽  
Open Shell ◽  
Triplet Ground State ◽  
Redox Active Ligand ◽  
Redox Active ◽  
Square Planar ◽  
Amine Adducts ◽  
Meso Position ◽  
Electronic Ground

ABSTRACT: The influence of a redox-active ligand on spin changing events induced by coordination of exogenous donors is investigated within the cobalt complex <b>[Co<sup>II</sup>(DPP<sup>•2‒</sup>)]</b>, bearing a redox-active <b>DPP<sup>2‒</sup></b> ligand (DPP = dipyrrin-bis-(<i>o,p</i>-di-tert-butylphenolato) with a pentafluorophenyl moiety on the meso-position. This square planar complex was subjected to coordination of THF, pyridine, tBuNH<sub>2</sub> and AdNH<sub>2</sub> (Ad = 1‑adamantyl), and the resulting complexes were analyzed with a variety of experimental (XRD, NMR, UV-Vis, HRMS, SQUID, Evans’ method) and computational (DFT, NEVPT2-CASSCF) techniques to elucidate the respective structures, spin states and orbital compositions of the corresponding octahedral bis-donor adducts, relative to <b>[Co<sup>II</sup>(DPP<sup>•2‒</sup>)]</b>. This starting species is best described as an open-shell singlet complex containing a <b>DPP<sup>•2‒</sup></b> ligand radical that is antiferromagnetically coupled to a low-spin (S = ½) cobalt(II) center. The redox-active <b>DPP<sup>n‒</sup></b> ligand plays a crucial role in stabilizing this complex, and in its facile conversion to the triplet THF-adduct <b>[Co<sup>II</sup>(DPP<sup>•2‒</sup>)(THF)<sub>2</sub>]</b> and closed-shell singlet pyridine and amine adducts <b>[Co<sup>III</sup>(DPP<sup>3‒</sup>)(L)<sub>2</sub>]</b> (L = py, tBuNH<sub>2</sub> or AdNH<sub>2</sub>). Coordination of the weak donor THF to <b>[Co<sup>II</sup>(DPP<sup>•2-</sup>)]</b> changes the orbital overlap between the <b>DPP<sup>•2‒</sup></b> ligand radical π-orbitals and the cobalt(II) metalloradical d-orbitals, which results in a spin-flip to the triplet ground state without changing the oxidation states of the metal or <b>DPP<sup>•2‒</sup></b> ligand. In contrast, coordination of the stronger donors pyridine, tBuNH<sub>2</sub> or AdNH<sub>2</sub> induces metal-to-ligand single-electron transfer, resulting in formation of low-spin (S = 0) cobalt(III)-complexes <b>[Co<sup>III</sup>(DPP<sup>3‒</sup>)(L)<sub>2</sub>]</b> containing a fully reduced <b>DPP<sup>3‒</sup></b> ligand, thus explaining their closed-shell singlet electronic ground states.

Structural features and electronic properties of a cupric complex with redox active 1-(2-pyridylazo)-2-phenanthrol (papl)

Polyhedron ◽  
2016 ◽  
Vol 108 ◽  
pp. 74-79 ◽  
Author(s):  
Robin A. Taylor ◽  
Alan J. Lough ◽  
Prashanth K. Poddutoori ◽  
Martin T. Lemaire
Keyword(s):  
Electronic Properties ◽  
Structural Features ◽  
Redox Active

Virtual Synthesis and Optoelectronic Properties of Prismatic Artificial Molecules of In-N and Zn-O: Comparative Studies

2006 ◽  
Vol 959 ◽  
Author(s):  
Liudmila A Pozhar ◽  
Gail J Brown ◽  
William C Mitchel
Keyword(s):  
Electronic Properties ◽  
Quantum Confinement ◽  
Optical Transition ◽  
Level Structure ◽  
Open Shell ◽  
Complete Active Space ◽  
Synthesis Conditions ◽  
Hartree Fock ◽  
Self Consistent Field ◽  
Molecular Synthesis

ABSTRACTThe Hartree-Fock (HF), restricted open shell HF (ROHF), configuration interaction (CI), complete active space (ICASCF), and multiconfiguration self-consistent field (MCSCF) methods provide sophisticated fundamental theory-based, computational tools to study structure, composition,chemistry and electronic properties of small artificial molecules composed of semiconductor compound atoms. These tools are used to synthesize virtually several prismatic In-N and Zn-O artificial molecules whose structure is derived from that of the symmetry elements of the respective wurtzite bulk lattices. Applications of spatial constraints to the atomic coordinates allow modeling molecular synthesis in quantum confinement, to obtain pre-designed molecules with tunable electronic properties. Relaxation of these constraints, or optimization, leads to the corresponding molecules synthesized in “vacuum”. The development of computational templates of the studied artificial molecules synthesized in confinement reflects effects of quantum confinement on the electronic level structure, bonding, the direct optical transition energy, and charge and spin density distributions of the molecules. Comparison of the structure and properties of these molecules to those of their vacuum counterparts leads to a conclusion that a small changes in atomic positions in otherwise structurally similar molecules cause a significant change in their electronic properties. Thus, the electronic properties of artificial molecules can be tuned by changing their synthesis conditions that are defined by atomistic details of quantum confinement where the molecules are synthesized.

Opto-Electronic Properties and Stability of Artificial Zinc Oxide Molecules

2006 ◽  
Vol 957 ◽  
Author(s):  
Liudmila A Pozhar ◽  
Gail J. Brown
Keyword(s):  
Zinc Oxide ◽  
Electronic Properties ◽  
Quantum Confinement ◽  
Electronic Materials ◽  
Optical Transition ◽  
Open Shell ◽  
Hartree Fock ◽  
Alumina Membranes ◽  
Self Consistent Field ◽  
Nanopore Arrays

ABSTRACTThe Hartree-Fock (HF), restricted open shell HF (ROHF), and multiconfiguration self-consistent field (CI/CASSCF/MCSCF) approximations are used to study computationally the electronic properties of zinc oxide artificial molecules whose structure and composition have been derived from those of the symmetry elements of the wurtzite bulk lattice of zinc oxide. Such molecules may provide realistic models for small ZnO quantum dots (QDs) synthesized in “vacuum” or quantum confinement (such as that of well-defined nanopore arrays of silica and alumina membranes) using variety of methods in particular, supercritical fluid deposition. The computational direct optical transition energy (OTE) of the confined molecule appears to be several times smaller than that of the corresponding vacuum cluster. The charge and spin density distributions of these molecules (CDDs and SDDs, respectively) differ significantly, revealing dramatic effects of quantum confinement on electronic properties of Zn-O clusters. The obtained results suggest that manipulations with the electronic properties of the confined clusters by sophisticated design of their quantum confinement may provide means for synthesis of Zn-O – based electronic materials that combine a wide, tunable band gap with large, tunable exciton binding energy.

Redox-Active N-Heterocyclic Carbenes: Design, Synthesis, and Evaluation of Their Electronic Properties

2009 ◽  
Vol 28 (23) ◽  
pp. 6695-6706 ◽  
Author(s):  
Evelyn L. Rosen ◽  
C. Daniel Varnado ◽  
Andrew G. Tennyson ◽  
Dimitri M. Khramov ◽  
Justin W. Kamplain ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Heterocyclic Carbenes ◽  
Design Synthesis ◽  
Redox Active

Inducing planarity in redox-active conjugated polymers with solubilizing 3,6-dialkoxy-thieno[3,2-b]thiophenes (DOTTs) for redox and solid-state conductivity applications

2020 ◽  
Vol 8 (22) ◽  
pp. 7463-7475 ◽  
Author(s):  
Sandra L. Pittelli ◽  
Shawn A. Gregory ◽  
James F. Ponder ◽  
Shannon K. Yee ◽  
John R. Reynolds
Keyword(s):  
Solid State ◽  
Conjugated Polymers ◽  
Electronic Properties ◽  
New Family ◽  
Redox Active ◽  
Optical And Electronic Properties

A new family of redox-active dioxythienothiophene (DOTT) polymers are studied for their solid state ordering and doping susceptibility, along with their optical and electronic properties.

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