Electron delocalization of new mixed-valent (MV) systems with the aid of lateral metal chelation is reported. 2,2'-Bipyridine (bpy) derivatives with one or two appended di-p-anisylamino groups on the 5,5'-positions and a coordinated [Ru(bpy)(2)] (bpy = 2,2'-bipyridine), [Re(CO)(3)Cl], or [Ir(ppy)(2)] (ppy = 2-phenylpyridine) component were prepared. The single-crystal molecular structure of the bis-amine ligand without metal chelation is presented. The electronic properties of these complexes were studied and compared by electrochemical and spectroscopic techniques and DFT/TDDFT calculations. Compounds with two di-p-anisylamino groups were oxidized by a chemical or electrochemical method and monitored by near-infrared (NIR) absorption spectral changes. Marcus-Hush analysis of the resulting intervalence charge-transfer transitions indicated that electron coupling of these mixed-valent systems is enhanced by metal chelation and that the iridium complex has the largest coupling. TDDFT calculations were employed to interpret the NIR transitions of these MV systems.
Organic electronic devices promise
cheaper solution processability
than their inorganic counterparts and allow for the vast tailorability
of synthetic chemistry to tune properties and efficiency. A critical
fundamental challenge is to understand the dynamics and mechanisms
of charge transport, particularly the role of defects and traps. We
use Kelvin probe force microscopy to compare potential energy distributions
of organic, semiconducting thin films to comparable histograms calculated
via our dynamic Monte Carlo simulation. A combination of theoretical
and experimental investigations indicates that the common assumption
of a Gaussian disorder model (GDM) is not always a good approximation
for these materials. Instead we find asymmetric distributions due
to nanoscale heterogeneity of charge and a resulting mix of Lorentzian
and Gaussian disorder fit through a Voigt profile. Determining a more
accurate model for disorder in these commonly used materials has the
potential to influence the future of organic electronics design.
The manufacturing of high definition OLED displays is limited by the resolution of the metal mask used in the OLED deposition process. We have developed the electroforming methods to make masks of 800 PPI and above.
Accreditation system of teacher education institutions is an important ensuring mechanism for teacher’s profession. American accreditation system of teacher education institutions refers to an assessment system that the National Council for Accreditation of Teacher Education (NCATE) with the institution’s application, making regular evaluation of the teacher education institutions according to the accreditation standards formulated by the National Council for Accreditation of Teacher Education , which abbreviates NCATE accreditation. NCATE is the first appraisal institution of national teacher education, which constantly improves the training quality of American teachers by being comprehensively appraised. It has been exerting great influence on the development of teacher education in America. And the effects are as following: convenient for students’ mobility among schools and the teachers’ transference to other states; encouraging competition among teacher education institution and academic mobility; leading to the regular internal assessment in teacher education institutions and promoting the professional level of pre-service education; and helping establish a quality assurance system for teacher education. The paper introduces the characteristics of NCATE and draws out enlightening points and reference for our institution accreditation o f teacher education
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.