A [2]rotaxane-based (1)H NMR spectroscopic probe for the simultaneous identification of physiologically important
Nai-Chia Chen1, Po-Yi Huang, Chien-Chen Lai
1Department of Chemistry, National Taiwan University, Taipei, Taiwan 10617, R.O.C.
Chemical Communications (Cambridge, England)
|October 11, 2007
Abstract:
We describe a [2]rotaxane molecule that exhibits distinct signals in its (1)H NMR spectra upon the complexation of physiologically important Li(+), Na(+), Mg(2+) and Ca(2+) ions; thus, the identification of these metal ions in solution is possible from the analysis of a single (1)H NMR spectrum of a single molecular sensor.
Related Concept Videos
01:17Chemical Shift: Internal References and Solvent Effects
In an NMR sample, precise measurement of the absolute absorption frequencies of nuclei is difficult. A standard internal reference compound is added, and the frequency difference between the reference signal and sample signals is measured.
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...
01:15¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
01:182D NMR: Overview of Heteronuclear Correlation Techniques
Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other axis.