Synthesis and properties of sulfur-functionalized triarylmethylium, acridinium and triangulenium dyes

Triangulenium dyes functionalized with one, two or three ethylthiol functionalities were synthesized and their optical properties were studied. The sulfur functionalities were introduced by aromatic nucleophilic substitution of methoxy groups in triarylmethylium cations with ethanethiol followed by partial or full ring closure of the ortho positions with nitrogen or oxygen bridges leading to sulfur-functionalized acridinium, xanthenium or triangulenium dyes. For all the dye classes the sulfur functionalities are found to lead to intensely absorbing dyes in the visible range (470 to 515 nm), quite similar to known analogous dye systems with dialkylamino donor groups in place of the ethylthiol substituents. For the triangulenium derivatives significant fluorescence was observed (Φf = 0.1 to Φf = 0.3).

Download Full-text

Fabrication of Transparent Mg(OH)2 Thin Films by Drop-Dry Deposition

Materials ◽

10.3390/ma14040724 ◽

2021 ◽

Vol 14 (4) ◽

pp. 724

Author(s):

Tong Li ◽

Masaya Ichimura

Keyword(s):

Thin Films ◽

Aqueous Solution ◽

Optical Properties ◽

Surface Morphology ◽

Magnesium Hydroxide ◽

Dry Deposition ◽

Visible Range ◽

Substrate Heating ◽

Water Effects ◽

Deposition Conditions

Magnesium hydroxide (Mg(OH)2) thin films were deposited by the drop-dry deposition (DDD) method using an aqueous solution containing Mg(NO3)2 and NaOH. DDD was performed by dropping the solution on a substrate, heating-drying, and rinsing in water. Effects of different deposition conditions on the surface morphology and optical properties of Mg(OH)2 thin films were researched. Films with a thickness of 1−2 μm were successfully deposited, and the Raman peaks of Mg(OH)2 were observed for them. Their transmittance in the visible range was 95% or more, and the bandgap was about 5.8 eV. It was found that the thin films have resistivity of the order of 105 Ωcm. Thus, the transparent and semiconducting Mg(OH)2 thin films were successfully prepared by DDD.

Download Full-text

Aromatic nucleophilic substitution reactions of ambident nucleophiles. II. Reactions of nitrite ion with nitrohalobenzenes

The Journal of Organic Chemistry ◽

10.1021/jo00902a005 ◽

1975 ◽

Vol 40 (14) ◽

pp. 2037-2042 ◽

Cited By ~ 16

Author(s):

T. J. Broxton ◽

D. M. Muir ◽

A. J. Parker

Keyword(s):

Nucleophilic Substitution ◽

Substitution Reactions ◽

Aromatic Nucleophilic Substitution ◽

Nitrite Ion ◽

Nucleophilic Substitution Reactions

Download Full-text

Comparative Study on Electronic Structure and Optical Properties of α-Fe2O3, Ag/α-Fe2O3 and S/α-Fe2O3

Metals ◽

10.3390/met11030424 ◽

2021 ◽

Vol 11 (3) ◽

pp. 424

Author(s):

Cuihua Zhao ◽

Baishi Li ◽

Xi Zhou ◽

Jianhua Chen ◽

Hongqun Tang

Keyword(s):

Optical Properties ◽

Optical Absorption ◽

Electronic Structures ◽

Density Functional ◽

Peak Strength ◽

Visible Range ◽

High Symmetry ◽

Functional Theory ◽

Optical Absorption Peak ◽

Calculation Results

The electronic structures and optical properties of pure, Ag-doped and S-doped α-Fe2O3 were studied using density functional theory (DFT). The calculation results show that the structure of α-Fe2O3 crystal changes after Ag and S doping, which leads to the different points of the high symmetry of Ag-doped and S-doped α-Fe2O3 with that of pure α-Fe2O3 in the energy band, as well as different Brillouin paths. In addition, the band gap of α-Fe2O3 becomes smaller after Ag and S doping, and the optical absorption peak shifts slightly toward the short wavelength, with the increased peak strength of S/α-Fe2O3 and the decreased peak strength of Ag/α-Fe2O3. However, the optical absorption in the visible range is enhanced after Ag and S doping compared with that of pure α-Fe2O3 when the wavelength is greater than 380 nm, and the optical absorption of S-doped α-Fe2O3 is stronger than that of Ag-doped α-Fe2O3.

Download Full-text