1983-60-4Relevant academic research and scientific papers
Anion-controlled ion-pair recognition of paraquat by a bis(m-phenylene)-32- crown-10 derivative heteroditopic host
Zhu, Kelong,Li, Shijun,Wang, Feng,Huang, Feihe
, p. 1322 - 1328 (2009)
It has been demonstrated that the complexation of the divalent salts of paraquat can be greatly improved (a Ka increase up to 219 times was observed) by the introduction of ion-pair recognition through use of urea moieties on the crown ether. This improvement is controlled by not only the solvent polarity but also the nature of the anion. Furthermore, it was found that the binding motif for paraquat guest incorporation into the heteroditopic host is anion-controlled in the solid state. The host-guest complex is a pseudorotaxane in the solid state when the two counterions of paraquat are trifluoroacetate anions while it is a taco complex when the two counterions are hexafluorophosphate or chloride anions.
Supramolecular amphiphiles based on a water-soluble chargetransfer complex: fabrication of ultralong nanofibers with tunable straightness
Wang, Chao,Guo, Yinsheng,Wang, Yapei,Xu, Huaping,Wang, Ruji,Zhang, Xi
, p. 8962 - 8965 (2009)
From curly to straight: The formation of a charge-transfer complex is driven by the combination of Coulombic attraction and charge transfer interactions. The chargetransfer complex which is obtained from a supramolecular amphiphile (see picture) is water-soluble and forms ultralong nanofibers, the straightness of which can be modulated by changing the pH of the reaction solution.
Effect of MCl2 (M = Hg, Zn, Cu) subphase on photoinduced electron transfer in a pyrazinium styryl dye Langmuir-Blodgett film
Zheng, Jie,Li, Fuyou,Yu, Xiaofen,Huang, Chun-Hui,Wu, Nianzhu
, p. 3049 - 3053 (2000)
An amphiphilic heteroaromatic styryl dye, 2-(4-dihexadecylaminostyryl)- 1,5-dimethylpyrazinium iodide (I) was synthesized. Its Langmuir-Blodgett films fabricated from different subphases, namely pure water (Ia), 10-5 M CuCl2 (Ib), 10-5 M ZnCl2 (Ic) and 10-5 M HgCl2 (Id), were characterized by UV-Vis spectra and XPS measurements. The photoelectrochemistry of these film-modified conducting transparent indium- tin oxide (ITO) electrodes was investigated on a traditional three-electrode cell. The experimental data indicated that the films fabricated from different subphases have distinctive photoelectric responses. Under ambient conditions (0.5 M KCl), the quantum yields of photoelectric conversion were 0.03, 0.05, 0.06, and 0.1% for films Ia, Ib, Ic and Id, respectively. The effects of factors such as bias voltage, methylviologen (MV2+), and hydroquinone (H2Q) on the photocurrent generation were also investigated. Based on the experimental data, a possible mechanism of photoinduced electron transfer in this system is proposed.
Effect of Charge Transport in Electrode-Confined N,N'-Dialkyl-4,4'-bipyridinium Polymers on the Current-Potential Response for Mediated, Outer-Sphere Electron-Transfer Reactions
Lewis, Nathan S.,Wrighton, Mark S.
, p. 2009 - 2017 (1984)
Mediated outer-sphere redox processes have been examined at rotating disk Pt/2+/+)n>surf electrodes.The 2+/+)n>surf is a redox polymer anchored to the surface and is formed from N,N'-bis-4,4'-bipyridinium, I.The polymer coverages for the electrodes selected for study are sufficiently great that Fe(phen)33+/2+, E0' = +1.03 V vs.SCE, shows no electrochemial response near its E0'.The mediated reduction of Fe(phen)33+ and a number of other outer-sphere oxidants is mass-transport limited when the Pt/2+/+)n>surf electrode is held ca. 100 mV more negative than E0'2+/+)n>surf = -0.45 v vs.SCE in CH3CN/0.1 M ClO4.However, contrary to theoretical expectations based only on the rate constant for reaction of Fe(phen)33+ with a surface PQ+, the onset of current for the mediated reduction is at the onset for 2+)n>surf -> +)n>surf reduction; in fact, the mediated reduction current in the onset region is directly proportional to the concentration of PQ+ in the surface-confined polymer.Data for Pt/2+*χFe(CN)63-/4-)n>surf electrodes show directly that charge transport in the polymer can be a limitation to the maximum steady-state mediation current in aqueous electrolyte solution at the coverages of 2+/+)n>surf that have been employed.The charge-transport properties of the polymer are concluded to control the current-potential profile, as has been reported previously for other surface-modified electrodes, for the large polymer coverages employed in these studies.
Near-Infrared-Emissive Amphiphilic BODIPY Assemblies Manipulated by Charge-Transfer Interaction: From Nanofibers to Nanorods and Nanodisks
Yin, Jia-Fu,Hu, Yi,Wang, Huan,Jin, Zhong,Zhang, Yi,Kuang, Gui-Chao
, p. 3088 - 3095 (2017)
A novel near-infrared (NIR)-emissive amphiphilic BODIPY derivative, BBDP, was successfully prepared and thoroughly characterized. The photophysical properties in various organic solvents and THF/H2O mixtures with different fractions of water were investigated. BBDP self-assembled into nanofibers in a water environment owing to its amphiphilic properties. Through charge-transfer interactions, BBDP co-assembled with a perylene bisimide derivative, PBI, and a viologen derivative, MV, to generate two superamphiphiles. These two superamphiphiles were able to aggregate in water media at appropriate concentrations. The BBDP–PBI charge-transfer complex formed nanorods, whereas the BBDP–MV aggregates expressed a disk-like morphology. This research paves the way for us to manipulate the morphology of dye assemblies.
Syntheses, X-ray Structures, Complexation, and Thermal Stability Studies of Bis(5-carbomethoxy-1,3-phenylene)-(3x + 2)-crown-x Compounds
Delaviz, Yadollah,Merola, Joseph S.,Berg, Michael A. G.,Gibson, Harry W.
, p. 516 - 522 (1995)
Bis(5-carbomethoxy-1,3-phenylene)-(3x + 2)-crown-x compounds have been synthesized in one step by reaction of methyl 3,5-dihydroxybenzoate (1) and the corresponding oligo(ethylene glycol) dichlorides (2a, 2b, and 2c) in the presence of NaH or KH in N,N-dimethylformamide (DMF).The smaller monoester, 5-carbomethoxy-1,3-phenylene-16-crown-5 (4c), was also isolated along with 3c.The X-ray crystal structures of these macrocycles (3b, 3c, and 4c) have been determined.Macrocycle 3b crystallizes in the triclinic space group P-1 with unit cell parameters of a = 8.632(2) Angstroem, b = 10.006(2) Angstroem, c = 11.527(2) Angstroem, α = 78.30(3) deg, β = 71.98(3) deg, γ = 65.00(3) deg.Macrocycle 3c crystallizes in the triclinic space group P-1 with unit cell parameters of a = 8.911(2) Angstroem, b = 9.497(2) Angstroem, c = 10.140(2) Angstroem, α = 93.66(2) deg, β = 94.03(1) deg, γ = 105.95(1) deg.Macrocycle 4c crystallizes in the triclinic space group with unit cell parameters of a = 8.748(2) Angstroem, b = 9.163(2) Angstroem, c = 12.025(3) Angstroem, α = 74.90(2) deg, β = 86.81(2) deg , γ = 61.73(2) deg.The thermal stabilities of these macrocycles and the complexation abilities of the bis(m-phenylene)-32-crown-10 derivatives with methyl viologen bis(hexafluorophosphate) (8) have been examined by 1H NMR spectroscopy.
Solvent effects on the redox-dependent binding properties of a viologen-based receptor for neutral organic molecules
Lilienthal, Ronald R.,Smith, Diane K.
, p. 3733 - 3739 (1995)
Cyclic voltammetry of a viologen-based cyclophane receptor, VH, in water, 10% acetonitrile/water, and acetonitrile is described. Minimal electrolyte was necessary in order to prevent precipitation of the reduced VH in aqueous solutions. Shifts in the half-wave potential of the first viologen reduction are observed in the presence of various substituted benzenes. The direction and magnitude of the shifts are explained in terms of two competing factors: (i) the change in the electron donor-acceptor character of the host that occurs upon reduction and (ii) the change in the hydrophobic/hydrophilic character of the host upon reduction. The first factor promotes binding of acceptor-substituted guests to the reduced host and donor-substituted guests to the oxidized host The second factor promotes binding of all the guests to the reduced host in aqueous solution. Large potential shifts are observed when both factors work in the same direction.
Highly effective binding of methyl viologen dication and its radical cation by p-sulfonatocalix[4,5]arenes
Guo, Dong-Sheng,Wang, Li-Hua,Liu, Yu
, p. 7775 - 7778 (2007)
(Figure Presented) The binding behaviors and thermodynamic origins of p-sulfonatocalix[4]arene (C4AS) and p-sulfonatocalix[5]-arene (C5AS) with methyl viologen (MV2+) have been investigated by the methods of isothermal titration calorimetry, NMR, and cyclic voltammetry, showing that the binding abilities of C4AS and C5AS and their host selectivity are dramatically pH-controlled, which is closely discussed from the viewpoint of thermodynamics. Moreover, the radical form of MV+? can also be effectively included by C4AS and C5AS.
Spectroelectrochemistry of Aromatic Ligands and Their Derivatives. 1. Reduction Products of 4,4'-Bipyridine, 2,2'-Bipyridine, 2,2'-Bipyrimidine, and Some Quaternized Derivatives
Braterman, Paul S.,Song, Jae-Inh
, p. 4678 - 4682 (1991)
Cathodic reductions and reduction products of 4,4'-bipyridine (I), N-methyl-4,4'-bipyridinium+ (monoquat; II), N,N'-dimethyl-4,4'-bipyridinium2+ (paraquat; III), 2,2'-bipyridine (IV), 4,4'-dimethyl-2,2'-bipyridine (V), the ethylene-bridged diquaternized derivative 6,7-dihydrodipyridopyrazinedium2+ (diquat; VI), unbridged diquaternized N,N'-dimethyl-2,2'-bipyridinium2+ (VII), and 2,2'-bipyrimidine (VIII) have been investigated by cyclic voltammetry and spectroelectrochemistry.As expected, quaternization and the incorporation of added nitrogens in the ring both lead to easier reductions.The radicals formed by one-electron reduction of I-IV show very similar spectra, assignable in terms of a simple Hueckel molecular orbital scheme.Thus, N-methylation lowers the energy of the LUMO in I but does not alter its nature.The same scheme, after allowing for loss of symmetry, correlates with established treatments of the reduction products of IV, which we have extended to VI, VIII, and the related reduced species.In all cases studied, the reduction orbital is related to ?(7) of biphenyl, the transition ?(6) -> ?(7) moves, where the rings can rotate, to lower energy on reduction, and bands in the near IR-visible region are observed and assigned to transitions from ?(7) to higher orbitals.
Simultaneous control of carriers and localized spins with light in organic materials
Naito, Toshio,Karasudani, Tomoaki,Ohara, Keishi,Takano, Takahiro,Takahashi, Yukihiro,Inabe, Tamotsu,Furukawa, Ko,Nakamura, Toshikazu
, p. 6153 - 6157 (2012)
An organic insulating crystal reversibly becomes a magnetic conductor under UV irradiation. The rapid and qualitative change in the physical properties is wavelength selective and explained by charge transfer between donor and photochemically active acceptor molecules. The photochemical redox reaction in the crystal produces a partially filled band and localized spins simultaneously.
