The proton NMR spectra for six compounds: 6-ethyldibenzo[b,i]-1,4,8,11-tetraazacyclotetradeca-4,6-diene(1), dibenzo[b,i]-1,4,8,11-tetraazacyclotetradecane, 1,3-bis(2-aminophenylamino)propane, 1,4,8,11-tetraazacyclotetradecane(cyclam), N-ethylaniline and diethylamine, were measured in ...
aThe techniques of Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H NMR) spectroscopy were used as tools for the identification of functional groups and the confirmation of the structure of the copolymers obtained. 使用了傅立叶变换红外线(FTIR)和氢核核磁反应(1H核磁共振)分...
The proton NMR. spectra of a series of aromatic amines, their N-oxides and the corresponding protonated species are analysed. The results for different protons are expressed in terms of differential chemical shifts of the N-oxide with respect to the corresponding amine or to the hydrocarbon. Thes...
In the NMR spectra of 31 P of H- Ca5(PO4)3OH and Li-Ca5(PO4)3OH, there is only one single chemical shift peak, 3.353 ppm and 3.323 ppm, respectively. This indicates that P exists in the form of Q0, i.e., free PO43-, in H-Ca5(PO4)3OH and Li-Ca5(PO4)3OH. The ...
(HCA II), a metalloenzyme with diffusion-limited catalytic efficiencies like MnSOD. For HCA II, joint neutron crystallography and NMR demonstrate a tyrosine residue with a pKaof 7.10 ± 0.10 at the active site44. The catalytic role of an ionizable Tyr34 for MnSOD is prominent during ...
ARTICLE Received 18 Dec 2015 | Accepted 12 May 2016 | Published 17 Jun 2016 DOI: 10.1038/ncomms11918 OPEN Operando NMR spectroscopic analysis of proton transfer in heterogeneous photocatalytic reactions Xue Lu Wang1,*, Wenqing Liu2,*, Yan-Yan Yu3, Yanhong Song2, Wen Qi Fang1, Daxiu Wei2,...
The 1H signal c was due to an overlapping signal from the protons in the aromatic ring, as well the protons of the two hydroxyl groups in the geminal diol. The signal designation was greatly facilitated by the COSY NMR spectrum (Fig. S1) in which a clear coupling between signal a and ...
Complexation of dihydrogen phosphate by an anion receptor containing six hydrogen bond donor groups has been shown to reduce the pKa of the bound anionic species to such an extent that addition of further aliquots of dihydrogen phosphate result in deprotonation of the bound species with the resultant...
The phenolic groups of tyrosine and thiol groups of cysteine are highlighted in red and blue, respectively. (b) Molecular structure of the dimer of Y7C revealed by NMR. Carbon, oxygen, and nitrogen are shown in gray, red, and purple, respectively. (c) Cross-sectional HRTEM image of the...
(Supplementary Fig.19). The presence of deuteron at C2 is further confirmed by NMR analysis of the purified umbelliferone product from the enzyme assay (Supplementary Fig.20). In contrast, spontaneous umbelliferone formation from 2OHpCCoA in 66% D2O in the absence ofAtCOSY showed no H/D...