The higher order high-resolution (31)P and (19)F NMR spectra of hexafluorocyclotriphosphazene (F(2)PN)(3) were measured at 183 K and interpreted using subspectral analysis and iterative fitting computation. (F(2)PN)(3) forms a rigid nine-spin system [A[X](2)](3) with D(3h) symmetry. Two complete and very similar sets of six experimental spin-spin coupling constants, (1)J(P,F), (2)J(P,P), (2)J(F,F), (3)J(P,F), (4)J(F,F)(cis) and (4)J(F,F)(trans), were determined for the first time. Theoretical DFT calculations of chemical shifts and coupling constants were performed to assess their predictive value. The PP/aug-cc-pVDZ treatment rendered the best agreement with experimental data.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/mrc.1549 | DOI Listing |
Anal Chem
January 2025
School of Petrochemical Engineering, Liaoning Petrochemical University, Fushun 113001, China.
Chiral discrimination is an indispensable tool that has pivotal importance in the assignment of absolute configuration and determination of enantiomeric excess in chiral compounds. A series of enantiomerically pure -1,2-diaminocyclohexane (-DACH)-derived benzamides were first synthesized by simple chemical steps, and 14 variated derivatives have been assessed as NMR chiral solvating agents (CSAs) for discrimination of the signals of mandelic acid (MA) in H NMR analysis. The highly efficient chiral recognition of CSA on different substrates, including MAs, carboxylic acids, amino acid derivatives, and phosphoric acids (32 examples), was expanded via H, F, and P NMR spectroscopy.
View Article and Find Full Text PDFBeilstein J Org Chem
December 2024
College of Chemistry and Material Science, Guangdong University of Education, Guangzhou 510303, China.
A novel series of D-A-D-type 9-phenyl-9-phosphafluorene oxide (PhFlOP) derivatives was prepared and is reported herein. The synthetic protocol involved 5 steps from commercially available 2-bromo-4-fluoro-1-nitrobenzene, featuring a noble-metal-free system, mild reaction conditions, and a good yield, especially for the final CsCO-facilitated nucleophilic substitution (77-91% yield). The characterization data obtained from IR and NMR spectroscopy (H, C, F, and P) as well as HRMS spectrometry were in full agreement with the expected structures, and single-crystal X-ray diffraction analysis was conducted to confirm the structure of compound .
View Article and Find Full Text PDFA new molecular switch is presented that combines both biradical and azobenzene motifs to perform visible light-induced constitutional and stereo-isomerisation within the same molecule. The insertion of isonitrile-functionalised azobenzenes into the four-membered biradical [˙P(μ-NTer)P˙] (1), yielding a phosphorus-centred cyclopentane-1,3-diyl (-4B and -5B), represents a straightforward method to generate the desired double switches (-4B and -5B) in excellent yields (>90%). The switching properties are demonstrated for the fluorinated species -5B and, interestingly, can occur either stepwise or simultaneously, depending on the order in which the sample is irradiated with red and/or green light.
View Article and Find Full Text PDFCommun Chem
December 2024
State Key Laboratory of Chemical Biology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zhangjiang Hi-Tech Park, Shanghai, China.
Polymers (Basel)
October 2024
Institute of Chemistry, St. Petersburg State University, 7/9 Universitetskaya Nab., 199034 St. Petersburg, Russia.
Cobaltocenium-containing (co)polysiloxanes (Cc-PDMSs) with terminal and side groups were synthesized by the reaction of catalyst-free hydroamination between ethynylcobaltocenium hexafluorophosphate and polysiloxanes comprising amino moieties as terminal and side groups. The conversion of NH groups in the polymers reaches 85%. The obtained (co)polysiloxanes "gelate" due to an increase in their molecular weight by approx.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!