Comparison of the Mechanical Properties of a Conjugated Polymer Deposited Using Spin Coating, Interfacial Spreading, Solution Shearing, and Spray Coating.

The mechanical properties of π-conjugated (semiconducting) polymers are a key determinant of the stability and manufacturability of devices envisioned for applications in energy and healthcare. These properties─including modulus, extensibility, toughness, and strength─are influenced by the morphology of the solid film, which depends on the method of processing. To date, the majority of work done on the mechanical properties of semiconducting polymers has been performed on films deposited by spin coating, a process not amenable to the manufacturing of large-area films.

Semiconducting polymer blends that exhibit stable charge transport at high temperatures.

Although high-temperature operation (i.e., beyond 150°C) is of great interest for many electronics applications, achieving stable carrier mobilities for organic semiconductors at elevated temperatures is fundamentally challenging.

Class III delocalization and exciton coupling in a bimetallic bis-ligand radical complex.

The geometric and electronic structure of an oxidized bimetallic Ni complex incorporating two redox-active Schiff-base ligands connected via a 1,2-phenylene linker has been investigated and compared to a monomeric analogue. Information from UV/Vis/NIR spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, electrochemistry, and density functional theory (DFT) calculations provides important information on the locus of oxidation for the bimetallic complex. The neutral bimetallic complex is conformationally dynamic at room temperature, which complicates characterization of the oxidized forms.

Double oxidation localizes spin in a Ni bis-phenoxyl radical complex.

The electronic structure of a doubly oxidized Ni salen complex NiSal(tBu) (Sal(tBu) = N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexane-(1R,2R)-diamine) has been investigated by both experimental and theoretical methods. The doubly oxidized product was probed by resonance Raman spectroscopy, UV-vis-NIR, and EPR to determine the locus of oxidation as well as the spectroscopic signature of the complex. It was determined that double oxidation of NiSal(tBu) affords a bis-ligand radical species in solution via the presence of phenoxyl radical bands at ν(7a) (1504 cm(-1)) and ν(8a) (1579 cm(-1)) in the Raman spectrum, and the loss of the intense NIR transition reported for the mono-radical complex (Angew.

Radical localization in a series of symmetric Ni(II) complexes with oxidized salen ligands.

Square-planar nickel(II) complexes of salen ligands, N,N'-bis(3-tert-butyl-(5R)-salicylidene)-1,2-cyclohexanediamine), in which R=tert-butyl (1), OMe (2), and NMe(2) (3), were prepared and the electronic structure of the one-electron-oxidized species [1-3](+·) was investigated in solution. Cyclic voltammograms of [1-3] showed two quasi-reversible redox waves that were assigned to the oxidation of the phenolate moieties to phenoxyl radicals. From the difference between the first and second redox potentials, the trend of electronic delocalization 1(+·) >2(+·) >3(+·) was obtained.

Non-innocent ligand behaviour of a bimetallic Cu complex employing a bridging catecholate.

The geometric and electronic structure of a bimetallic Cu Schiff-base complex and its one-electron oxidized form have been investigated. The two salen units in the neutral complex 1 are linked via a bridging catecholate function, and the coupling between the two Cu(II) d(9) centres was determined to be weakly antiferromagnetic on the basis of solid-state magnetic studies (J = -3 cm(-1)), and variable-temperature electron paramagnetic resonance (EPR) (J = -3 cm(-1)). Theoretical calculations (DFT) were in agreement with the experimental results (J = -7 cm(-1)), and provided insight into the coupling mechanism for the neutral system.

Non-innocent ligand behavior of a bimetallic Ni Schiff-base complex containing a bridging catecholate.

The geometric and electronic structure of a bimetallic Ni Schiff-base complex and its one-electron oxidized form have been investigated in the solid state and in solution. The two salen units in the neutral complex 1 are linked via a bridging catecholate function. The one-electron oxidized form [1](+) was determined to exist as a ligand radical species in solution, with the electron hole potentially localized on the redox-active dioxolene, the phenolate ligands, or delocalized over the entire ligand system.

Influence of the chelate effect on the electronic structure of one-electron oxidized group 10 metal(II)-(disalicylidene)diamine complexes.

The neutral and one-electron oxidized group 10 metal, Ni(II), Pd(II) and Pt(II), six-membered chelate Salpn (Salpn = N,N'-bis(3,5-di-tert-butylsalicylidene)-1,3-propanediamine) complexes have been investigated and compared to the five-membered chelate Salen (N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-ethanediamine) and Salcn (N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexane-(1R,2R)-diamine) complexes. Reaction of the Salpn complexes with 1 equivalent of AgSbF(6) affords the oxidized complexes which exist as ligand radical species in solution and in the solid state. The solid state structures of the oxidized complexes have been determined by X-ray crystal structure analysis.