Papers by Author: Cong Bin Fan

Abstract: A novel unsymmetrical photochromic diarylethene 1-(2-methyl-3-benzothienyl)-2-{2-n-butyl-5-[2-(1,3-dioxolane)]-3-thienyl}perfluorocyclopentene(1O) was synthesized, and its photochromic, fluorescent and optical strorage properties were investigated. The compounds 1O exhibited remarkable photochromism both in solution and in PMMA film, and the results showed that the cyclization/cycloreversion process of the compound was determined to be the zeroth/first order reaction. In addition, this new photochromic system also exhibited remarkable optical storage character.

Abstract: A novel unsymmetrical diarylethene derivative 1-[2-methyl-5-(4-pyridine)-3-thienyl]-2-[2-methyl-5-(4-hydroxylphenyl)-3-thienyl]hexafluorocyclopentene (1a) was successfully synthesized. The properties of the compound, including photochromic and fluorescence properties of the diarylethene were also investigated systematically. The results showed that absorption maxima of this compound were observed at 606 nm in methanol and at 612 nm in PMMA amorphous film, respectively, upon irradiation with 297 nm UV light. In methanol solution, the open-ring isomer of the diarylethene 1 exhibited relatively fluorescence at 499 nm when excited at 414 nm. This new photochromic compound also exhibited remarkable optical storage character.

Abstract: A new purple photochromic diarylethene compound, [1- (2-ethyl-3-benzothienyl)-2-(1,3,5-trimethyl-4-pyrazolyl)]perfluoroclopentene (1a), was synthesized and its photochemical properties were investigated in detail. The results demonstrated that the compound has good photochromism in PMMA amorphous film and fluorescence switching properties.

Abstract: A novel photochromic hybrid diarylethene bearing an isoxazole moiety was synthesized and its photochromic and fluorescent properties were also investigated. This compound exhibited good photochromism and functioned as a fluorescence switch upon alternating irradiation with UV and visible light both in solution and in PMMA film. Using this diarylethene 1c as optical storage was performed successfully.

Abstract: A novel unsymmetrical diarylethene derivative 1-[2-methyl-5-(3-trifluoromethylphenyl)-3-thienyl]-2-[2-methyl-5-(4-methoxyphenyl)-3-thienyl]hexafluorocyclopentene (1a) was designed and successfully synthesized. The properties of the compound, including photochromic and electrochemical properties of the diarylethene were also investigated systematically. The results showed that this compound exhibited reversible photochromism, reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light both in solution and in PMMA film, and its absorption maxima were observed at 606 nm in methanol and at 613 nm in PMMA amorphous film, respectively, upon irradiation with 297 nm UV light. Besides, the electrochemcial switching property can be potential use for electrochemistry data storage.

Abstract: A new red diarylethene compound, 1,2-bis[2-n-hexyl-5-hydroxymethyl -3-thienyl]-perfluorocyclopentene (1o), was synthesized and its photochemic properties and fluorescence were studied. Specifically, photochromism in solution and in poly-methylmethacrylate (PMMA) amorphous films were investigated. The results showed that it exhibited good photochromism in both solution and PMMA amorphous film under photoirradiation. In addition, the compound exhibited relatively strong fluorescence that can be useful for the design of the fluorescence molecule switch.

Abstract: A new photochromic diarylethene compound, 1-[2-methyl-5-(3-chlorophenyl) -3-thienyl]-2-[2-methyl-5-(2-pyridine)-3-thienyl]perfluorocyclopentene(1a) was synthesized. its photochromism was investigated. It exhibited good photochromism and functioned as an effective fluorescent photoswitch both in solution and in PMMA films.

Abstract: A unsymmetrical diarylethene derivative bearing both indole and phenyl moieties was synthesized. At the same time, its photochromic properties and fluorescence switch were investigated in detail. The results showed that this compound exhibited reversible photochromism, undergoing reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light in solution, and its absorption maxima were observed at 625 nm in hexane, upon irradiation with 297 nm UV light. The fluorescence intensity of diarylethene decreased dramatically along with the photochromism from open-ring isomer to closed-ring isomer upon irradiation with 297 nm UV light in PMMA. In hexane solution, the open-ring isomer of the diarylethene 1 exhibited relatively strong fluorescence at 439 nm when excited at 385 nm.This new photochromic system also exhibited remarkable optical storage character.

Abstract: An unsymmetrical diarylethene derivative bearing both benzothienyl and thienyl moieties, in which a malononitrile group was substituted at the 5-position of the thienyl ring, was synthesized. This compound undergo a reversible electrocyclic rearrangement, generating strongly colored closed-ring isomer upon irradiation with UV-light which show nonfluorescence, while exposure to light in the visible range triggers the cycloreversion to the colorless open-ring form that exhibits strong fluorescence properties. This properties of molecular photochromism were developed that showed both photo switches and fluorescence switches. The erasable and rewritable photo-images on this photochromic diarylethene were successfully demonstrated. This developments are crucial for fundamental research and eventual technical application for high-density optical data storage.

Abstract: Fluorescent photoswitching molecule in which photochromic diarylethene with six-number phenyl unit and thiophene ring attached a phenyl methoxy group was synthesized. The compound exhibited pronounced photochromic and synchronous fluorescence switching properties. Irradiation of the open form of compound with UV light resulted in immediate photocyclization to the blue closed form with nonfluorescence; the colorless open form with fluorescence character could be regenerated by irradiation with visible light. In terms of potential use for optical storage and readout, this compound displays fluorescence discrimination between its open and closed form. This fluorescence switching could be the basis of a remote control nondestructive readout method.