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941.
Chi‐Ming Che Prof. Dr. Chi‐Chung Kwok Dr. Siu‐Wai Lai Dr. Andreas F. Rausch Dipl.‐Chem. Walter J. Finkenzeller Dr. Nianyong Zhu Dr. Hartmut Yersin Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(1):233-247
The syntheses, crystal structures, and detailed investigations of the photophysical properties of phosphorescent platinum(II) Schiff base complexes are presented. All of these complexes exhibit intense absorption bands with λmax in the range 417–546 nm, which are assigned to states of metal‐to‐ligand charge‐transfer (1MLCT) 1[Pt(5d)→π*(Schiff base)] character mixed with 1[lone pair(phenoxide)→π*(imine)] charge‐transfer character. The platinum(II) Schiff base complexes are thermally stable, with decomposition temperatures up to 495 °C, and show emission λmax at 541–649 nm in acetonitrile, with emission quantum yields up to 0.27. Measurements of the emission decay times in the temperature range from 130 to 1.5 K give total zero‐field splitting parameters of the emitting triplet state of 14–28 cm?1. High‐performance yellow to red organic light‐emitting devices (OLEDs) using these platinum(II) Schiff base complexes have been fabricated with the best efficiency up to 31 cd A?1 and a device lifetime up to 77 000 h at 500 cd m?2. 相似文献
942.
Dipl.‐Chem. Jürgen Bauer Prof. Dr. Holger Braunschweig Dipl.‐Chem. Peter Brenner Dipl.‐Chem. Katharina Kraft Dr. Krzysztof Radacki Dipl.‐Chem. Katrin Schwab 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(39):11985-11992
Syntheses of the first heteroleptic N‐heterocyclic carbene (NHC)–phosphane platinum(0) complexes and formation of the corresponding Lewis acid–base adducts with aluminum chloride is reported. The influence of N‐heterocyclic carbenes on tuning the Lewis basic properties of the metal complexes was judged from spectroscopic, structural, and computational data. Conclusive experimental evidence for the enhanced Lewis basicity of NHC‐containing complexes was provided by a transfer reaction. 相似文献
943.
A. Amiraslani 《Linear and Multilinear Algebra》2013,61(12):1419-1431
Scalar polynomials as approximations to more general scalar functions lead to the study of scalar polynomials represented in a variety of classical systems of polynomials, including orthogonal systems and Lagrange polynomials, for example. This article, motivated in part by analogy with the existing methods for linear factor polynomial deflation in the monomial basis, finds forward and backward deflation formulae for several such representations. It also finds the sensitivity factor of the deflation process for each representation. 相似文献
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We have carried out an extensive exploration of the gas-phase basicity of archetypal neutral bases across the periodic system using the generalized gradient approximation (GGA) of the density functional theory (DFT) at BP86/QZ4P//BP86/TZ2P. First, we validate DFT as a reliable tool for computing proton affinities and related thermochemical quantities: BP86/QZ4P//BP86/TZ2P is shown to yield a mean absolute deviation of 2.0 kcal/mol for the proton affinity at 298 K with respect to experiment, and 1.2 kcal/mol with high-level ab initio benchmark data. The main purpose of this work is to provide the proton affinities (and corresponding entropies) at 298 K of the neutral bases constituted by all maingroup-element hydrides of groups 15-17 and the noble gases, that is, group 18, and periods 1-6. We have also studied the effect of step-wise methylation of the protophilic center of the second- and third-period bases. 相似文献
948.
In the general atomic setting of an unconditional basis in a (quasi-) Banach space, we show that representing the spaces
of m-terms approximation as Lorentz spaces is equivalent to the verification of two inequalities (Jackson and Bernstein),
and that the validity of these two properties is equivalent to the Temlyakov property. The proof is very direct and, especially,
does not use interpolation theory. We apply this result to establish a representation theorem when the norm of the (quasi-)
Banach space is given by a quadratic variation formula (thanks to a condition called the p-reverse inequality). This quadratic
variation framework is in fact very rich and contains, as examples, the cases of Hardy spaces. We also consider the cases
of "weighted" Hardy and Lebesgue spaces when the weight belongs to a Muckenhoupt class and the basis is a wavelet basis. This
provides a new example of bases well adapted to approximation. 相似文献
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