It has been shown that the quantum yield of the photochemical conversion of adenine and the corresponding nucleosides and nucleoside 5'-phosphates in liquid (pH 5.6 and 2.0) and frozen aqueous solutions do not exceed 10(-4). The quantum yield of the photoconversion of guanine-containing nucleosides and nucleoside 5'-phosphates in liquid aqueous solution (pH 5.6) after removal of oxygen by passing through nitrogen and in the frozen state do not exceed 0.3 x 10(-4). The quantum yield in oxygen-containing liquid aqueous solutions increase to 0.3 x 10(-3), i.e. to values commensurate with the quantum yield of pyrimidine photolysis.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC344387PMC
http://dx.doi.org/10.1093/nar/2.8.1365DOI Listing

Publication Analysis

Top Keywords

quantum yield
16
aqueous solution
8
nucleosides nucleoside
8
nucleoside 5'-phosphates
8
5'-phosphates liquid
8
aqueous solutions
8
exceed 10-4
8
10-4 quantum
8
liquid aqueous
8
photochemistry purine
4

Similar Publications

Multicomponent reactions (MCRs), highly sought-after methods to produce atom-, step-, and energy-economic organic syntheses, have been developed extensively. However, catalytic asymmetric MCRs, especially those involving radical species, remain largely unexplored owing to the difficulty in stereoselectively regulating the extraordinarily high reactivity of open-shell radical species. Herein, we report a conceptually novel catalytic asymmetric three-component radical cascade reaction of readily accessible glycine esters, α-bromo carbonyl compounds and 2-vinylcyclopropyl ketones via synergistic photoredox/Brønsted acid catalysis, in which three sequential C-C (σ/π/σ) bond-forming events occurred through a radical addition/ring-opening/radical-radical coupling protocol, affording an array of valuable enantioenriched unnatural α-amino acid derivatives bearing two contiguous stereogenic centers and an alkene moiety in moderate to good yield with high diastereoselectivity, excellent enantioselectivity and good -dominated geometry under mild reaction conditions.

View Article and Find Full Text PDF

Emission Tuning of Nonconventional Luminescent Materials via Cluster Engineering.

Small

January 2025

Guangxi Key Laboratory of Optical and Electronic Materials and Devices, Guangxi Colleges and Universities Key Laboratory of Natural and Biomedical Polymer Materials, College of Materials Science and Engineering, Guilin University of Technology, No.12 Jian'gan Rd., Qixing District, Guilin, 541004, China.

Nonconventional Luminescent Materials (NLMs) with distinctive optical properties are garnering significant attention. A key challenge in their practical application lies in precisely controlling their emission behavior, particularly achieving excitation wavelength-independent emission, which is paramount for accurate chemical sensing. In this study, NLMs (Y1, Y2, Y3, and Y4) are synthesized via a click reaction, and it is found that excitation wavelength-dependent emission correlates with molecular cluster formation.

View Article and Find Full Text PDF

Addressing the challenges of the efficiency and stability of red perovskite nanocrystals is imperative for the successful deployment of these materials in displays and lighting applications. the structural dynamic changes of red perovskite quantum dots (PQDs) are explored using a flow chemistry system to solve the above hurdles. First, the ultrabright red-emitting PQDs of CsPb(Br,I) are achieved by adjusting ligand distribution (oleic acid and oleyamine) in combination with different flow rates and equivalence ratios.

View Article and Find Full Text PDF

Quasi-2D perovskite made with organic spacers co-crystallized with inorganic cesium lead bromide inorganics is demonstrated for near unity photoluminescence quantum yield at room temperature. However, light emitting diodes made with quasi-2D perovskites rapidly degrade which remains a major bottleneck in this field. In this work, It is shown that the bright emission originates from finely tuned multi-component 2D nano-crystalline phases that are thermodynamically unstable.

View Article and Find Full Text PDF

Photocycloreversion reactions of three diarylethene derivatives whose structures differ only in the placement of two sulfur atoms in the cyclopentene rings are investigated. Despite the minuscule differences between the molecules, both the yields and times of the photoreactions vary considerably. Using UV-vis and infrared femtosecond spectroscopy and quantum chemical dynamics simulations, we elucidate the relationships among the quantum yield, electronic and vibrational relaxation time, and structural properties of the dithienylethene photoswitches.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!