Luminescent 1D chain of platinum(II) terpyridyl units with p-dithiobenzoquinone organometallic linker: self-aggregation imparted from Pt...Pt/pi-pi interactions

Unlike p-dithiobenzoquinone (), which is extremely reactive and has never been isolated, the metal-stabilised p-dithiobenzoquinone [Cp*Ir(eta4-C6H4S2)] () was prepared and used as an efficient organometallic linker to construct novel supramolecular assemblies. Treatment of with the electrophilic Pt(II)(terpy) building blocks produced the supramolecular assembly {[Pt(terpy){Cp*Ir-p-(eta4-C6H4S2)}Pt(terpy)][OTf]4}n (), which was fully characterised and its molecular structure was determined by X-ray crystallography. The structure of revealed the presence of pi-pi and Pt[dot dot dot]Pt interactions among individual molecules describing a 1D chain. Complex showed unusual UV/Vis absorption and luminescence behaviour at low temperature, imparted from self-aggregation mediated by pi-pi and Pt...Pt interactions.     

Enhanced efficiency of direct-space structure solution from powder X-ray diffraction data in the case of conformationally flexible molecules

A strategy is reported for assessing the feasibility of molecular conformations within direct-space structure-solution calculations of organic molecular crystal structures from powder X-ray diffraction data, focusing in particular on the genetic algorithm technique for structure solution in which fitness is defined as a function of the whole-profile figure-of-merit Rwp. The strategy employs a readily computed distance-based function to assess the feasibility of the molecular conformation in each trial structure generated in the genetic algorithm calculation, and structures considered to have low-feasibility conformations are penalized within the evolutionary process. The strategy is shown to lead to significant improvements in the success rate of structure-solution calculations in the case of flexible molecules with a significant number of conformational degrees of freedom.     

Enantioselective Pd-catalyzed allylic alkylation of indoles by a new class of chiral ferrocenyl P/S ligands

Chiral ferrocenyl heterobidentate P/S ligands bearing both central and planar chirality were prepared from (S)-Ugi's amine via a three-step modular synthesis. Through systematic screening and optimization, L8 was found to be the best ligand for Pd-catalyzed asymmetric allylic alkylation of indoles with ee's up to 96% being attained.     

Platinum(II) complexes with pi-conjugated, naphthyl-substituted, cyclometalated ligands (RC N N): structures and photo- and electroluminescence

The crystal structures and photophysical properties of mononuclear [(RC N N)PtX](ClO4)n ((RC N N)=3-(6'-(2'-naphthyl)-2'-pyridyl)isoquinolinyl and derivatives; X=Cl, n=0; X=PPh(3) or PCy(3), n=1), dinuclear [(RC N N)2Pt2(mu-dppm)](ClO4)2 (dppm=bis(diphenyphosphino)methyl) and trinuclear [(RC N N)3Pt3(mu-dpmp)](ClO4)3 (dpmp=bis(diphenylphosphinomethyl)phenylphosphine) complexes are presented. The crystal structures show extensive intra- and/or intermolecular pipi interactions; the two (RC N N) planes of [(RC N N)2Pt2(mu-dppm)](ClO4)2 (R=Ph, 3,5-tBu2Ph or 3,5-(CF3)2Ph) are in a nearly eclipsed configuration with torsion angles close to 0 degrees. [(RC N N)PtCl], [(RC N N)2Pt2(mu-dppm)](ClO4)2, and [(RC N N)3Pt3(mu-dpmp)](ClO4)3 are strongly emissive with quantum yields of up to 0.68 in CH2Cl2 or MeCN solution at room temperature. The [(RC N N)PtCl] complexes have a high thermal stability (T(d)=470-549 degrees C). High-performance light-emitting devices containing [(RC N N)PtCl] (R=H or 3,5-tBu2Ph) as a light-emitting material have been fabricated; they have a maximum luminance of 63,000 cd m(-2) and CIE 1931 coordinates at x=0.36, y=0.54.     

工程力学如何为开发中国西部做贡献

本文就开发中国西部地区中工程力学能做的贡献提出了建议。涉及交通运输,资源和能源的开发利用,发展微量水农业,创建新的农牧业,培养人才等八个方面。      

A semi-analytical method for structure-internal liquid interaction problems

A composite structure-internal liquid element is proposed in this paper. Through the use of analytical functions in two orthogonal directions, the three-dimensional problem of coupled structure-internal liquid vibration is reduced to a one-dimensional one, resulting in a drastic reduction in computing efforts.Cylindrical and conical frastum composite elements are proposed to suit different problems, and examples are presented to demonstrate the accuracy of the method.     

Proof of Potassium Ions by Luminescence Signaling Based on Weak Gold–Gold Interactions in Dinuclear Gold(I) Complexes

Two versatile luminescence ion probes for potassium ions have been designed based on the “switching on and off” of the gold–gold interaction. Addition of potassium ions to the gold(I ) complexes [Au₂(R₂PCH₂PR₂)(S-benzo[15]crown-5)₂] (see the picture; R=Ph, cyclohexyl; M⁺=K⁺) give rise to an intense red luminescence.     

Highly efficient carbazolylgold(iii) dendrimers based on thermally activated delayed fluorescence and their application in solution-processed organic light-emitting devices

A new class of C^C^N ligand-containing carbazolylgold(iii) dendrimers has been designed and synthesized. High photoluminescence quantum yields of up to 82% in solid-state thin films and large radiative decay rate constants in the order of 10⁵ s⁻¹ are observed. These gold(iii) dendrimers are found to exhibit thermally activated delayed fluorescence (TADF), as supported by variable-temperature emission spectroscopy, time-resolved photoluminescence decay and computational studies. Solution-processed organic light-emitting diodes (OLEDs) based on these gold(iii) dendrimers have been fabricated, which exhibit a maximum current efficiency of 52.6 cd A⁻¹, maximum external quantum efficiency of 15.8% and high power efficiency of 41.3 lm W⁻¹. The operational stability of these OLEDs has also been recorded, with the devices based on zero- and second-generation dendrimers showing maximum half-lifetimes of 1305 and 322 h at 100 cd m⁻², respectively, representing the first demonstration of operationally stable solution-processed OLEDs based on gold(iii) dendrimers.

A new class of carbazolylgold(iii) C^C^N dendrimers with thermally activated delayed fluorescence properties has been designed and synthesized for the realzaqtion of operationally stable solution-processed organic light-emitting devices.