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Questions related from Bryan Po-Wen Chen
I have a photochromic organic compound not dissolving in anything except for hot toluene or DMF. I want to make a PMMA bulk material with my compound dispersed in a cube/sheet of PMMA as...
20 July 2023 2,041 1 View
Hi, I have few photochromic powder in crystal, and some of them are photochromic, some are not. I want to correlate the photochromicity with the way of crystal packing. Therefore, I ran a...
10 October 2022 5,280 0 View
I have resolved several aromatic compounds' absolute structures in single-crystal x-ray, and all of them showed cofacial/slipped close-packing/stacking of the aromatic rings. Later, I used VESTA...
06 April 2022 8,663 6 View
I am trying to correlate the IR spectrum and single crystallography data. In single crystal IR spectra, I found some inter-molecular hydrogen bonds were stronger (from wavenumber shift), and I...
07 November 2021 1,697 3 View
I have been running excited state (Mostly TD) geometry optimization in Gaussian or Q-chem. Most of my compounds have exclusive HOMO -> LUMO (amplitude^2 ~ 1) at excitation state 1 (B3LYP). But...
11 May 2021 8,469 3 View
How to determine FQY for photoswitchable compounds? I found most related publications didnt mention, or just said that they used "Absolute quantum yield spectrometer." I think such technique...
01 November 2020 8,154 5 View
# opt TD(singlets,nstates=3) uB3LYP/6-31g(d,p) # opt TD(singlets,nstates=3) B3LYP/6-31g(d,p) ------------------------------------------------------------------------ Im currently trying to...
28 February 2018 9,912 3 View
Im currently trying to find a stable geometry for a small organic dye for its first excited state. # opt TD=singlets B3LYP/6-31+G(d,p) One of my most possible structure guess is obtained from...
30 January 2018 8,088 8 View
Amide-nitrogen is said that cannot be a hydrogen bond acceptor (Ref. 1). In my Gaussian opt simulation (B3LYP/6-31+G(d,p)) the result was consistent, which Amide-N didnt form intramolecular...
07 November 2017 6,935 6 View
I have an azo dye, which I suspect it may form intramolecular hydrogen bond after photoisomerization. The intramolecular hydrogen bond may have faciliated the proton transfer. After...
04 October 2017 2,567 7 View
I use carboxylic ferrocene (Fc-COOH) and react with acetic anhydride in H3PO4. Hopefully I can get acetylation on the Cp ring without COOH. But from H NMR, it seems that I got 100% of acetylation...
15 March 2016 7,994 3 View
In an oxidation process by cyclic voltammetry, compared to naked ITO electrode, I got less positive peak when ITO was coated with by solid phase catalyst. Do i interpret the less positive peak as...
30 April 2015 728 8 View
How does the exciton get separated under light irradiation? Prof. Kamat published one paper `Charge Separation and Catalytic Activity of Ag@TiO2 Core-Shell Composite Clusters under UV-Irradiation`...
15 March 2015 4,038 4 View
I think these materials are semiconductors, but why not all exciton recombinations with respect to different materials all show photons coming, so called quantum dots? Do the efficiencies of...
09 February 2015 5,304 3 View
I have synthesized a small organic compound and prepared crystal for x-ray single crystal measurement. They were beautifully transparent, and I remove the remaining DCM from vial. After ~30 mins,...
01 January 1970 492 14 View
Crystal violet lactone in acidic condition (opened ring) is deep blue-purple color, resulting from the absorbance around 600 nm. Why is it not emitting fluorescence from this excitation (FL >...
01 January 1970 8,334 4 View
01 January 1970 2,118 3 View
