Silica-supported Polysiloxanes with Dithiacrown Ether Groups and Their Platinum Complexes

The present paper represents the syntheses of polypropyloxymethyldithia 15-crown-5 and 18-crown-6 supported on silica and their platinum complexes. The platinum complexes are effective catalysts for the hydrosilylation of olefins with triethoxysilane. The influences of temperature, amount of platinum complexes used and the nature of olefins used on the catalytic activity of the complexes are also investigated in this paper.

1, 1'—BIS (BENZYLSELENO) FERROCENE PLATINUM COMPLEX AS HYDROSlLYLATION CATALYST FOR OLEFINS

1, 1'--Bis(benzylseleno)ferrocene and its platinum complex were synthesized. It was found that the platinum complex was efficient catalyst for the hydrosilylation of olefins with triethoxysilane.

UV-Vis Spectrum and the Third-order Nonlinear Optical Properties of the Chiral Camphorderived β-diketonate Platinum Complexes

UV-Vis spectrum and the third-order nonlinear optical properties of the chiral camphor-derived β-diketonate have been studied at the B3LYP/6-31G＊ level. The results showed that the introduction of electron-drawing group -CF3 and -C3F7 on β-diketonate made the strongest absorption peak red-shift and the lowest energy absorption blue-shied. Introduction of -OC2H5 on the benzene or pyridine ring made the lowest energy absorption blue-shift. When the -C2H3 was introduced on the benzene or pyridine ring, the lowest energy absorption was red-shifted. Introduction of electron-donating group on β-diketonate can enlarge their nonlinear optical properties. On the contrary, the introduction of electron-drawing group dropped it down.

CROWN FUNCTIONALIZED LINEAR POLYSILOXANE PLATINUM COMPLEX AS HYDROSILYLATION CATALYST

A modified method of preparing crown functionalized linear polysiloxane has been described.4'-allylbenzo-15-crown-5 was subjected to hydrosilylation with methyldichlorosilane,followed bypolycondensation with silanol-terminated polydimethylsiloxane to give the title crownfunctionalized linear polysiloxane. It was found that the polysiloxane could be coordinated withplatinum salt to form platinum complex, which could catalyze the hydrosilylation of olefins withtriethoxysilane efficiently.

SILICA-BOUND CROWN ETHERS PLATINUM COMPLEX AS HYDROSILYLATION CATALYST

Silica-bound 15-Crown-5, 18-Crown-6 with a spacer of propyloxymethyl and their platinum complexes have been synthesized. It was found that they were efficient catalysts for the hydrosilylation of olefms with triethoxysilane in the temperature range of 60 to 130 ℃.

A NEW TYPE OF CROWN FUNCTIONALIZED POLYSILOXANE AND ITS PLATINUM COMPLEX

A new type of crown functionalized polysiloxane, in which the crown moieties were incorporated into main chain, and its platinum complex were synthesized. The polysiloxane was synthesized from 3, 16-dihydroxy-1- thia - 5, 8, 11, 14- tetraoxacycloheptadecane via etheritication with ω-chloroundecene, followed by hydrosilylation with triethoxysilane, cohydrolysis with D_4, sequentially. Treating the polysiloxane with potassium cholroplatinite, the title complex was obtained. It was found that the platinum complex exhibited high catalytic activity in the hydrosilylation of olefins with triethoxysilane.

NETWORK CROWN ETHER POLYMERS WITH CENTRIC FUNCTIONAL GROUP (Ⅳ) SYNTHESIS OF NETWORK CROWN ETHER POLYMER WITH PENDANT DIETHYLAMINO THIAALKYL GROUP AND ITS PLATINUM COMPLEX

The title polymer was prepared from 5-diethylamino-3-thia-pentyl glycidyl ether anddiethylene glycol bisglycidyl ether via ring-opening copolymerization. It was found that thisreaction could be catalyzed by sodium, but not Lewis acid. The obtained polymer can coordinatewith platinum compound, and the platinum complex is a new kind of catalyst for thehydrosilylation of olefins with triethoxysilane.

Platinum complexes as phosphorescent emitters in highly efficient organic light-emitting diodes

Applications of platinum complexes as phosphorescent emitters in high efficiency organic light-emitting diodes （OLEDs） were shortly discussed in this paper. Key recent studies on highly efficient blue, green, red and white-phosphorescent OLEDs based on Pt complexes are presented in terms of efficiency and color quality.

SYNTHESIS AND CHARACTERIZATION OF A SILICA-SUPPORTED CARBOXYMETHYLCELLULOSE PLATINUM COMPLEX AND ITS CATALYTIC BEHAVIORS FOR HYDROGENATI0N OF AR0MATICS

A silica-supported carboxymethylcellulose platinum complex (abbreviated as SiO_2-CMC-Pt) has been prepared and characterized by XPS. Its catalytic properties for hydro-genation of aromatic compounds were studied. The results showed that this catalystcould catalyze the hydrogenation of phenol, anisol, p-cresol, benzene and toluene to cyclo-hexanol, cyclohexyl methyl ether, p-methyl cyclohexanol, cyclohexane and methylcyclo-hexane, respectively in 100% yield at 30℃ and 1 atm. In the hydrogenation of phenol,COO/Pt ratio in SiO_2-CMC-Pt has much influence on the initial hydrogenation rate andthe selectivity for the intermediate product, cyclohexanone. The highest initial rate andthe highest yield of cyclohexanone both occur at COO/Pt ratio of 6. The complex is stableduring the reaction and can be used repeatedly.

STUDISS ON HETERO-MACROCYULIC POLYETHER(Ⅲ).THE SYNTHESES OF 10-TELLURABENZO-15-CROWN-5 AND ITS PLATINUM COMPLEX AS WELL AS ITS CATALYTIC BEHAVIOR IN HYDROSILYLATION

The syntheses of a new type of heteromacrocyclic polyether- 2,3-benzo-1,4,7,13-tetraoxa-10-telluracyclopentadeca-2-ene(L),and its pla- tinum complex(PtL_2Cl_2)were described.The catalytic activity of this complex for the hydrosilylation of olefins by triethoxysilane was investigated.

STUDIES ON HETERO-MACROCYCLIC POLYETHER (Ⅱ). THE SYNTHESIS OF PLATINUM COMPLEX OF 10-SELENABENZO-15-CROWN-5 AND ITS CATALYTIC BEHAVIOR IN HYDROSILYLATION

The title complex (PtL_2Cl_2) was synthesized by reacting 10-selenabenzo-15-crown-5 (L) with potassium chloroplatinite. Its catalytic activity for the hydrosilylation of olefins by triethoxysilane, was investi gated.

Hydrogenation of Toluidines Catalyzed by Silica-supported Carboxymethylcellulose-platinum Complex

The hydrogenation of toluidines catalyzed by silica-supported carboxymethyl cellulose platinum complex forms methylcyclohexlamines in high yields, such as m-toluidine to 3-methylcyclohexylamine, o-toluidine to 2-methylcyclohexylamine, and p-toluidine to 4-methylcyclohexylamine in 97%, 96.7% and 98.2% yields, respectively, at 30 ℃ and under atmospheric hydrogen pressure. The yields were remarkably affected by the Pt content in the complex, the kind of solvent and the reaction temperature. The catalyst was very stable and could be reused several times without remarkable change in the catalytic activity.

SYNTHESIS AND CHARACTERIZATION OF DVE-CO-MA DERIVATIVES OF CIS- PLATINUM COMPLEXES

Copolymer of divinyl ether and maleic anhydride (DVE-co-MA) derivatives of cis-platinum complexes were synthesized and characterized by elementary analysis, IR and XPS ( X-ray photoelectron spectroscopy). The behavior of the products in biological environment was also studied. UV-visible and fluorescence spectra show that these polymer derivatives are able to exchange ligands with selected nucleophilic groups in biological environment.

Synthesis and photophysical and electrochemical properties of new cyclometalated platinum complex containing oxadiazole ligand

A new cyclometalated platinum complex containing 2, 5-bis(naphthalene-1-yl)-1,3,4-oxadiazole ligand was synthesized and characterized. The UV-Vis absorptions and photoluminescent properties of the ligand and its platinum complex were investigated. A characteristic metal-ligand charge transfer absorption peak at 439 nm in the UV spectrum and a strong emission peak at 625 nm in the photoluminescence spectrum were observed for this complex in dichloromethane. Cyclic voltammtry (CV) analysis shows that the EHOMO (energy level of the highest occupied molecular orbital) and ELUMO (energy level of the lowest unoccupied molecular orbital) of the platinum complex are about 、5.69 and 、3.25 eV, respectively, indicating that the oxadiazole-based platinum complex has a potential application in electrophosphorescent devices used as a red-emitting material.

SYNTHESIS AND CATALYTIC ACTIVITY OF PLATINUM COMPLEX OF ACRYLATE TERPOLYMER WITH Se, N BIDENTATE LIGAND

Acrylate terpolymer- bound Se, N bidentate ligand was synthesized fromthe side chain chlorine of copolymer and β- dimethylamino -β - hydroxyl diethyl selenoether. The polymer - supported platinum complex exhibited highcatalytic activity in the hodrosilylation of olefins with triethoxysilane.

Tetradentate cyclometalated platinum complex enables high-performance near-infrared electroluminescence with excellent device stability

Due to the high decay rate of the non-radiative transition of long wavelengths, the molecular design of efficient and stable near-infrared(NIR) electroluminescent materials remains a big challenge. Herein,a new tetradentate cyclometalated platinum(II) complex with an N∧C∧C∧N coordinated framework has been developed and used as a dopant for NIR organic light-emitting diodes(OLEDs). The complex exhibited a short-lived(0.5–1.5 μs) metal-to-ligand charge transfer(MLCT) excited state in doped and neat films. The resulting NIR OLEDs(λ_(EL)= 730 nm) achieved maximum external quantum efficiency(EQE_(max))of 5.2% and radiance of 74626 m W sr^(-1)m^(–2). Of note, the device exhibited excellent stability with operational lifetime of 119 h for LT_(90). This work demonstrated the great potential of tetradentate platinum(II)complexes in the field of NIR OLEDs.

High-efficiency circularly polarized emission from liquid-crystalline platinum complexes

Realizing both a high emission efficiency and luminescence dissymmetry factor(g_(lum))in circularly polarized solution processable organic light-emitting diodes(CP-OLEDs)remains a significant challenge.In this contribution,two chiral phosphorescent liquid crystals based on cyclometalated platinum complexes are prepared,in which the chiral s-2-methyl-1-butyl group is introduced into the cyclometalating ligand and the mesogenic fragment is attached to the periphery of the ancillary ligand.The platinum complexes exhibit both smectic and chiral nematic phases as evidenced by polarized optical microscopy,differential scanning calorimetry and small-angle X-ray diffraction.Remarkably,a high photoluminescent quantum efficiency of over 78%and clear circularly polarized luminescent signal with g_(PL)of about 10^(-2)are observed for the complexes.Further,solution-processed CP-OLEDs show maximum external quantum efficiencies(EQE)of over 15%and strong circularly polarized electroluminescent signals with a g_(EL)≈10^(-2).This research demonstrates that both liquid crystallinity and the number of chiral centers play key roles in improving the chiroptical property,paving the way for a new approach for the design of high-efficiency CPL emitters.

Synthesis, Structure, and DNA Binding of a Platinum(Ⅱ) Complex Based on the 3,4,5-Trimethoxy-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline

A new platinum（Ⅱ） complex of [Pt（chda）（3,4,5-triopip）]Cl·2H2O（1） based on 3,4,5-trimethoxy-phenyl-1 H-imidazo[4,5-f][1,10]phenanthroline（3,4,5-triopip） has been synthesized by hydrothermal methods and its consequences are characterized by elemental analysis, IR, single-crystal X-ray diffraction, UV-Vis absorption and fluorescent spectrum. The UV-Vis absorption studies reveal that the molecule undergoes considerable interaction with the nucleic acid. In this mononuclear structure, the platinum adopts a four-coordinated square planar geometry, which may favor the intercalation between the neighboring bases of the G-quadruplex（G4） DNA.

Handedness-inverted polymorphic helical assembly and circularly polarized luminescence of chiral platinum complexes

Circularly polarized luminescence(CPL)materials have potential applications in three-dimensional(3D)displays,quantum encryption,and optical sensors.The development of single-component CPL materials with polymorphic assembly and handedness inversion remains a significant challenge.Herein,we present the access of such materials by controlling the underlying assembly pathway of well-designed chiral emitters.A pair of enantiomeric platinum complexes(R)-1 and(S)-1 decorated with a chiralα-methylbenzyl isocyanide ligand were prepared.By using the mixed-solvent(THF/n-hexane,THF=tetrahydrofuran)or high-concentration condition,these complexes were found to assemble via a cooperative or isodesmic pathway with significantly enhanced yellow or red emission,respectively.The aggregate samples obtained via these conditions show efficient CPL(dissymmery factor|glum|>0.02,emission quantum yieldΦ>20%).Interestingly,different assembly pathway leads to helical nanoribbons or nanofibers with opposite handedness from the complex with the same molecular chirality.This has been unambiguously and consistently manifested by circular dichroism and CPL spectral analysis and transmission electron,scanning electron,and atomic force microscope studies.This work demonstrates an appealing example of constructing polymorphic helical architectures with highly efficient CPL and inverted handedness thanks to the excellent assembly and emission of platinum complexes.

Stimuli-responsive cyclometalated platinum complex bearing bent molecular geometry for highly efficient solution-processable OLEDs

Smart materials,such as stimuli-responsive luminescence,have attracted much attentions due to their potential application in semiconductor filed.In this context,platinum complexes of(dfppy-DC)Pt(acac) and(dfppy-O-DC)Pt(acac) were prepared and characterized,in which(2-(4',6'-difluorophenyl)pyridinato-N,C2')(2,4-pentanedionato-0,0)Pt(Ⅱ) was used as the planar emission core and 9-(4-(phenylsulfonyl)phenyl)-9 H-carbazole(DC) was regard as the bent pendent.Both platinum complexes showed bright emission in solution and solid state,concomitant with charming external-stimuli-responsive emission under mechanical grinding,organic solvent vapors and pressure.The change emission color spanned from yellow to near-infrared region.Using the platinum complexes as the dopant,solution processable organic light-emitting diodes(OLEDs) were fabricated and a maximum external quantum efficiency of ~18% was achieved,which is the highest value among the reported solution-processable OLEDs based on externalstimuli-responsive luminescence.This research demonstrated that platinum complex can show promising stimuli responsive emission via ingenious molecular design,indicating a novel way for developing the smart materials in semiconductor filed.