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.

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.