红色磷光喹喔啉铂(II)配合物及其有机电致发光器件的制备

利用2,3-二苯基喹喔啉和氯亚铂酸钾(K2PtCl4)反应, 合成了一种新型喹喔啉铂的配合物(DPQ)Pt(acac), 通过元素分析, 1H NMR测定对配合物结构进行了表征, 结果显示得到的是目标化合物. 利用紫外光谱和荧光光谱对配合物进行了研究. 利用该材料作为磷光染料制备了结构为ITO/NPB (21 nm) /NPB∶7%(DPQ)Pt(acac) (17.5 nm) /BCP (7 nm)/ Alq3 (21 nm)/ Mg∶Ag(10∶1)(120 nm)/Ag(10 nm)的有机电致发光器件(OLED). 结果表明, 该配合物在442和485 nm处存在单重态1MLCT(金属到配体的电荷跃迁)和三重态3MLCT的吸收峰; 在632 nm 处有较强的金属配合物三重态的磷光发射; 该器件的启动电压是5.0 V, 器件的最大亮度为1516 cd·m-2, 外量子效率为0.66%, 流明效率为0.26 lm·W-1, 是一种红色磷光材料.     

TheT 1 state ofp-nitroaniline and related molecules: A CNDO/S study

The nature of the lowest energy triplet state (T ₁) ofp-nitroaniline (PNA), N,N-dimethyl-p-nitroaniline (DMPNA) and nitrobenzene (NB) is reexamined using the semiempirical CNDO/S-CI method with selected parameter options. The present results indicate that in the case of theunperturbed molecules the short-axis polarized * n() triplet largely localized at the acceptor end of the molecule may lie lower in energy than the triplet manifold counterpart of the intense intramolecular charge-transferD ⁺ A ^–singlet excitation. Computations suggest, however, that polar solvents strongly stabilize the PNA and DMPNA * charge-transfer triplet relative to other excitations, whereas specific solvent hydrogen-bonded interactions stabilize the * n() triplet of NB below those of * character. These assignments allow a rationalization of phosphorescence lifetime data,T _n T ₁ absorption measurements and relative photochemical behavior.     

Triplet state interaction of Safranine T with inorganic cations in different solvents

The triplet-triplet absorbance of Safranine T (3,7-Diamino-2,8-dimethyl-5-phenylphenaznium chloride) has been studied in a series of polar and non-polar solvents. When non-aqueous solvents are gradually added to the aqueous solution of Safranine T (ST) the lifetime of the triplet state decreases. It has been established that the dye forms weak complex with the solvent molecules. The quenching of triplet state of ST by Fe²⁺, Co²⁺ and Mn²⁺ has been studied in different solvents. The double protonated long-lived triplet species of ST; absorbs at 580 nm. The decay of the triplets follows first order kinetics. The quencher generates reduced semidye from ³ST by electron transfer mechanism. The reduction of ³ST by Mn²⁺ and Fe²⁺ is thermodynamically allowed but electron transfer from Co²⁺ to ST is endoergic. The mechanism of quenching by Co²⁺ can be explained as compensation by charge transfer mechanism between ³ST and Co²⁺.     

双铜簇合物的EPR谱、磁性与电子结构研究

本文报导了77K及室温下新合成的双铜簇合物(DMF)₂]·4DMF的EPR及磁性测定结果。所得到的三套EPR谱与磁矩以及S_cc-EHMO量化计算结果综合分析,确认两套谱归属于铜离子上的未配对电子,另一套归属于簇合物三重态电子。固态时顺磁性主要是三重态的贡献,溶液时主要来自铜离子。 该簇合物的电子结构特点:双铜之间有微弱作用。双铜与桥基、端基成键后的剩余价态很少,铜离子上的电子自旋浓度约为单铜化合物的3%,因此铜离子的两套EPR谱强度相当弱。分子轨道前沿的能级接近简并,轨道上的电子形成热激发三重态,造成一套三重态EPR谱。因此,可认为该化合物是一种新型自身磁稀释的三重态双铜簇合物。     

Total Synthesis of Arylnaphthalene Lignans through a Photochemical Key Step

The total syntheses of three arylnaphthalene lignans ( ANL s) were developed: Vitrofolal E ( 1 ), Noralashinol C ( 2 ), and Ternifoliuslignan E ( 3 ). These natural products have in common a missing substituent in 2-position of the naphthalene moiety ( 2H-ANL s). The key step of these syntheses is a regioselective intramolecular Photo-Dehydro-Diels-Alder (PDDA) reaction with (1,7)naphthalenophanes as primary products. A further improvement of the photochemical step was achieved by triplet sensitization with xanthone, allowing the use of more efficient UVA lamps. It should be noted that this work is a continuation of a previous publication about the total synthesis of lignans using the PDDA reaction.^[1]     

Synthesis and photophysical properties of lead phthalocyanines

This work reports on the synthesis and photophysical parameters of tetra-and octa-substituted new lead phthalocyanines. The complexes synthesized are: 1,4-(tetraphenoxyphthalocyaninato)lead (7a), 1,4-(tetra-tert-butylphenoxyphthalocyaninato)lead (7b), 2,3-(tetraphenoxyphthalocyaninato)lead (8a), 2,3-(tetra-tert-butylphenoxyphthalocyaninato)lead (8b), 2,3-octaphenoxyphthalocyaninatolead (9a) 2,3-[octakis(4-t-butylphenoxyphthalocyaninato)]lead (9b). Photophysical properties were studied for these complexes in a dimethylsulfoxide, dimethylformamide, toluene, tetrahydrofuran and chloroform. The fluorescence spectra were different from excitation spectra due to demetallation upon excitation. High triplet quantum yields ranging from 0.70 to 0.88 (in DMSO, DMF and toluene) and low triplet lifetimes (20–50 μs in DMSO, and <10 μs in the rest of the solvents) were observed due to the presence of heavy atom.     

Synthesis and photochemistry of novel bromo substituted stilbene derivatives as triplet state sensitizers for the generation of singlet oxygen

We have presented the synthesis and characterization of three new bromo substituted stilbene derivatives,p-3,4,5-trimethoxy-p'- 2,3,4,5,6-pentabromostilbene(C1),p-N,N-dimethylamino-p'-2,3,4,5,6-pentabromostilbene(C2) and p-N,N-diphenylamino-p'- 2,3,4,5,6-pentabromostilbene(C3) in this letter.The UV/vis absorption and photoluminescence were investigated in various solvents.The maximal absorption wavelength of C1 exhibited blue-shift to those of C2 and C3 in different solvents.No florescence emission could...     

Exact Self-consistent Integral Equations for the Distribution Functions of Classical Fluids

Abstract

The source particle method (SPM) due to Percus and Verlet of obtaining the single particle density, and the pair and triplet distribution functions of classical fluids (as well as in the variational theory of Bose liquids) is studied. Generalizations of hypernetted chain (HNC) equations are generated by holding fixed the coordinates of the definite group of source particles. Special attention is paid to the triplet distribution function and to the self-consistent calculation of the bridge function (elementary diagram) contribution in the pair distribution function. A comparison with the other exact integral equation theories including the BBGKY-equations is discussed.     

The synthesis and photophysical properties of novel cationic tetra pyridiloxy substituted aluminium, silicon and titanium phthalocyanines in water

This work reports on the synthesis, characterisation and photophysical properties of new unquaternized β-2,(3)-tetra-(2 pyridiloxy) aluminium(III) (3a), silicon(IV) (3b), titanium(IV) (3c) phthalocyanines and their water-soluble quaternized counterparts, 4a, 4b and 4c, respectively. The water-soluble silicon(IV) (4b) and titanium(IV) (4c) phthalocyanine derivatives were found to be aggregated in aqueous media but were partially or fully disaggregated in the presence of a surfactant Cremophor^® EL (CEL). The photophysical properties of aggregated complexes were investigated both in the presence of CEL and in pH 11 alone. Low triplet and fluorescence yield were obtained in pH 11 but an improvement was achieved upon addition of CEL for the aggregated complexes. The unquaternized silicon(IV) phthalocyanine complex (3b) gave the highest triplet quantum yield of 0.77 in DMF followed by its quaternized derivative (4b) with triplet yield of 0.73 in pH 11 plus CEL. The highest triplet lifetime of 220 μs was obtained for 4b in the presence of CEL. Higher fluorescence yields of 0.23 were obtained for quaternized water-soluble aluminium(III) phthalocyanine derivative (4a) in the presence of CEL.     

Umbrella inversions of cyclononatetraenylidenes at ab initio and DFT

Barriers of umbrella inversions for non-planar triplet 2-, 3-, 4-, or 5-X-2,4,6,8-cyclononatetraenylidenes, inverting through planar transition states, appear roughly four times lower in energy than their corresponding singlet states, at ab initio and DFT levels (X = H, F, Cl, Br). Relative activation energies for these racemization (), follow electronegativity for both singlet and/or triplet states of 2-X-2,4,6,8-cyclononatetraenylidenes (F > Cl > Br > H). This trend does not hold for species with halogens further away from the carbenic center: 3-, 4-, or 5-X-2,4,6,8-cyclononatetraenylidenes. Frequency calculations show one negative force constant for all planar species (transition states), while they appear positive for non-planar minima.