Lin-Pei Jin

Multifunctional photoelectrochemical logic gates based on a hemicyanine sensitized semiconductor electrode

A new amphiphilic hemicyanine dye, (E)-1,3,3-trimethyl-2-[2-(4-N-methyl-N-hexadecylaminophenyl)ethenyl]indolinium iodide (MHID) has been synthesized and successfully transferred onto a semiconducting transparent indium-tin oxide (ITO) electrode by Langmuir–Blodgett (LB) techniques. The photoelectric conversion properties of the dye MHID monolayer fabricated ITO electrode have been investigated in a three electrode photoelectrochemical cell. The observed photocurrent strongly depends on the applied electrode potential and the concentrations of the electron acceptors and donors. By using electron acceptors and (or) donors as input and photocurrent as output, respectively, we have fabricated this artificial photoelectrochemical system as multifunctional logic gates, corresponding to a series of logic operations (YES, OR, XOR and INHIBIT). Importantly, the gates of this photoelectrochemical system have been interconnected to demonstrate computation as a half-subtractor, with Eu3+ and hydroquinone (H2Q) as the two inputs and the cathodic photocurrent and the absolute value of the photocurrent as the two outputs, respectively.

A microscale multi-functional metal-organic framework as a fluorescence chemosensor for Fe(III), Al(III) and 2-hydroxy-1-naphthaldehyde

A microscale metal-organic framework [Eu(atpt)1.5(phen)(H2O)]n (H2atpt=2-aminoterephthalic acid, phen=1,10-phenanthroline) (Eu-MOF) was synthesized and characterized by elemental analysis, luminescence spectrum, powder X-ray diffraction, dynamic light scattering and scanning electron microscope. The fluorescence response of Eu-MOF to metal ions and aldehydes showed that Eu-MOF is highly selective to Fe(III), Al(III) and 2-hydroxy-1-naphthaldehyde (2-OH-NA). Eu-MOF could be utilized as a multi-functional fluorescence chemosensor for Fe(III), Al(III) and 2-hydroxy-1-naphthaldehyde (2-OH-NA). The detection limit of Fe(III), Al(III) and 2-OH-NA was 45, 10 and 36μM, respectively. The corresponding sensing mechanisms were explored.

Crystal structure of MSIA and photochromism of Eu3+–MSIA–phen complex

Abstract The title compound N,N-bis(N-methylenesuccimido) β-alanine (MSIA) was synthesized through the Mannich reaction of succimide with β-alanine in the formaldehyde solution. The structure of MSIA was determined by single crystal X-ray diffraction. The molecule has two five-membered rings with a dihedral angle of 74.45° instead of 180° in the same plane. The chain of β-alanine chooses the serrated conformation rather than linear one. Its Eu3+ complex with 1,10-phenanthroline(phen) has good photochromism in aqueous media.

Photocurrent generation of a novel chromoionophore combining D–π–A dye and aza-15-crown-5 ether in LB monolayer films

A novel amphiphilic chromoionophore, N-[4-(2,3,6,7,8,9,11,12-octahydro-5H-1,4,10,13,7-benzotetraoxaazacyclopentadecin-7-yl)butyl]-4-{2-[4-(N-methyl-N-hexadecylamino)phenyl]ethenyl}quinolinium bromide (Crown D), containing a D–π–A styryl dye and an aza-15-crown-5 ether group was synthesized, and successfully transferred onto an indium–tin oxide (ITO) electrode by the Langmuir–Blodgett technique. The effect of different metal cationic subphases on the π–A isotherm of Crown D was investigated. The photoelectric conversion properties of the chromoionophore LB monolayer films were studied. The results show that the photocurrent generation properties of the film strongly depend on the radius of the metal ions coordinated with the aza-15-crown-5 ring of the dye.

Multifunctional molecular materials combining photoelectric conversion and second-order optical nonlinearities in LB monolayer films

Abstract A series of multifunctional dye molecules with different relative positions of electron-accepting group, ( E )- N -methyl-4-[2-(4- N -methyl- N -hexadecylaminophenyl) ethenyl]-2-quinolinium iodide (MHQ-2), ( E )- N -methyl-4-[2-(4- N -methyl- N -hexadecylaminophenyl)ethenyl]-4-quinolinium iodide (MHQ-4) and ( E )- N -methyl-4-[2-(4- N -methyl- N -hexadecylaminophenyl)ethenyl]-6-quinolinium iodide (MHQ-6) were synthesized. These amphiphilic dye molecules were successfully transferred onto ITO electrode or quartz by Langmuir–Blodgett (LB) technique. The second-harmonic generation (SHG) and photoelectric conversion (PEC) properties of their monolayers were studied under identical conditions. The sequence of χ (2) and the photocurrent external quantum yield under the same conditions is MHQ-4>MHQ-2>MHQ-6, implying that the relative position of acceptor plays an important role in SHG and PEC properties.

Enhancement of photocurrent generation of two novel stilbazolium dye dimers in LB monolayer films

Novel amphiphilic stilbazolium dye dimers, bis{[1-(N-methylpyridinium-4-yl)-2-(3-methoxy-4-octadecyloxyphenyl)]ethenyl}methane diiodide (BPOM) and bis{[1-(N-methylpyridinium-4-yl)-2-(4-octadecyloxyphenyl)]ethenyl}methane diiodide (BPO) were synthesized, and they were successfully transferred onto semiconducting transparent indium–tin oxide (ITO) as H-aggregates by Langmuir–Blodgett (LB) techniques. The photocurrent generation properties of monolayer films of these dyes were investigated in a traditional three-electrode cell. A steady cathodic photocurrent was obtained upon excitation of the dye LB monolayer films deposited on an ITO electrode. The observed photocurrent generation quantum yield strongly depended on the applied electrode potential, concentration of the redox couples in the electrolyte solution, and the chemical structure of the dye congeners. The dye monomers, (E)-N-methyl-4-[2-(3-methoxy-4-octadecyloxyphenyl)ethenyl]pyridinium iodide (POM) and (E)-N-methyl-4-[2-(4-octadecyloxyphenyl)ethenyl]pyridinium iodide (PO) as the standards for comparison were also studied. Data show that the photocurrent generation quantum yields are 0.35% and 0.26% for BPOM and BPO, respectively, while those for POM and PO are 0.19% and 0.11%, respectively. From the photoelectrochemical measurement, the enhanced photocurrent generation properties in the dimer compared with those in the corresponding monomer were observed.