Synthesis and Characterization of Donor-Acceptor-Donor Triads Containing Tetrathiafulvalene and Naphthalene Diimide Units: Towards Regulation of the Intermolecular Charge-Transfer Interaction by Varying the Attached Side Groups

A series of donor-acceptor-donor triads 16 consisting of tetrathiafulvalene and naphthalene diimide units were synthesized and characterized. UV/Vis spectroscopic and cyclic voltammetric studies indicate that these triads show negligible intramolecular charge transfer interaction in the ground state. In contrast to that of the reference compound 36, their fluorescence intensities were reduced in the following sequences: 3≈4≈5≈6<1≈2, which is probably due to photoinduced electron transfer in triads 16. Two solid forms (yellow and green) of triads 15 were obtained, while only green form for triad 6 was obtained under the same conditions. Studies of the yellow and green forms with UV, XRD and DSC were performed. It was suggested that varying the attached side groups may regulate intermolecular charge transfer interactions in the solid state.

Effect of Energy Transfer on UV Spectra of “H-shaped” Azobenzene Derivatives

A series of “H-shaped” organic dimers （azobenzene derivatives） exhibit linear absorption red shift compared with their corresponding monomers experimentally. Dipolar interaction model is not appropriate for the azobenzene derivatives due to the small distance between two “D-π-A” chains. Energy transfer model is suggested for explanation of the absorption red shift. Two necessary conditions for energy transfer were verified. In addition, bi-exponential florescence-delay behavior of the dimer as well as Bella＇s quantum chemistry calculation shows evidence of energy transfer.

Spin transfer torque in the semiconductor/ferromagnetic structure in the presence of Rashba effect

Spin transfer torque in magnetic structure occurs when the transverse component of the spin current that flows from the nonmagnetic medium to ferromagnetic medium is absorbed by the interface. In this paper, considering the Rashba effect on the semiconductor region, we discuss the spin transfer torque in semiconductor/ferromagnetic structure and obtain the components of spin-current density for two models：（i） single electron and（ii） the distribution of electrons. We show that no matter whether the difference in Fermi surface between semiconductor and Fermi spheres for the up and down spins in ferromagnetic increases, the transmission probability decreases. The obtained results for the values used in this article illustrate that Rashba effect increases the difference in Fermi sphere between semiconductor and Fermi sphere for the up and down spins in ferromagnetic. The results also show that the Rashba effect, brings an additional contribution to the components of spin transfer torque, which does not exist in the absence of the Rashba interaction. Moreover, the Rashba term has also different effects on the transverse components of the spin torque transfer.

信任促进两人层次知识转移的机制的研究

近来,如何促进知识在组织中、组织间有效地转移,已成为众多经理人和研究人员关注的热点。过去的文献都是从信任如何促使人们更愿意参与知识转移的角度来研究信任对知识转移的促进作用。本文提出,信任对知识转移的促进作用不仅在于促使人们更愿意参与知识转移,还在于能够使知识转移活动对于参与双方来说变得更容易。进一步,本文运用符号互动理论的观点,从信任对知识转移双方互动过程的影响的角度入手,论述了信任能通过以下三种方式使知识转移变得更容易:(1)使知识转移双方沟通加深;(2)促使提供方划清自己的知识领域;(3)促进双方积极的归因。

Redox-Active Dihydrophenazine-Based Macrocycle:Synthesis,Conformation-Adaptive Behavior and Host-Guest Complexation with Tetracyanoquinodimethane

A novel macrocycle based on conformation-adaptive and electron-rich dihydrophenazine was designed and synthesized.On the one hand,the macrocycle showed host-guest interactions with tetracyanoquinodimethane(TCNQ)driving by charge transfer interaction between them.Meanwhile,host-guest complexation was accompanied by fluorescence quenching and conformational change of the macrocycle.On the other hand,the oxidation of the macrocycle resulted in its diradical cation analogue and induced the release of the guest molecule TCNQ,thereby accomplishing reversible binding dynamics.Therefore,this work wellillustrates the chemical and structural versatility of dihydrophenazine in the synthesis of macrocycles and their host-guest chemistry.

Tuning Thermal Gelling Behavior of N-isopropylacrylamide Based Copolymer through Introducing Cucurbit[8]uril Ternary Complex on Side-chain

Thermo-gelation polymers have attracted increasing attention over decades. However, rare facile tuning method of sol-gel transition temperature restricted the wider application. Preceding study indicated that supramolecular interactions demonstrated a powerful means to control the structure and property of polymeric materials. Here we designed an N-isopropylacrylamide （NIPAM） based thermo-sensitive copolymer with naphthyl （Np） on its side chain. Positive-charged side-chain ternary complex was formed with cucurbit[8]uril （CB[8]） and methylviologen （MV2＋） via CB[8]-enhanced intermolecular charge-transfer （CT） interaction. Introducing the ternary complex CB[8]/MV2＋/Np on side-chain altered microstructure of macromolecular chains and led to a strong tendency for thermo gelation. Altering content of CB[8] and MV2＋ changed content of the positive-charged side-chain ternary complex and varied gelation temperature. Therefore, introducing supramolecular interaction endowed the hydrogel with tunable gelation property.

Synthesis, spectroscopic, and electrochemical properties of two dyads consisted of tetrathiafulvalene and carbazole

Two donor-σ-acceptor molecules containing tetrathiafulvalene(TTF)and carbazole moieties were synthesized bythe reactionof 9-(4-bromo-butyl)-carbazole(1)with 2,6-bis(hexylthio)-3-(2-cyanoethylthio)-7-(methylthio)-tetrathiafulvalene(2)or2,6-bis(2-cyanoethylthio)-3,7-bis(methylthio)tetrathiafulvalene(3)in the presence of CsOH·H_(2)O,respectively.The structures of the molecules were characterized by 1 H NMR,13 C NMR,MS,and elemental analyses.They showed negligible intramolecu-lar charge-transfer interaction in their ground states as indicated by their UV-Vis spectroscopics and cyclic voltammetry results.Compared with carbazole,their fluorescence was strongly quenched,which implied that a photo induced electron transfer(PET)interaction between TTF and carbazole moieties occurred.