as shown in the mass spectra below. We can often solve the puzzle of an entire molecule's identity by putting the 'pieces'--the fragment ions--together. To solve the puzzle, we must realize that the largest peak in a mass spectrum usually corresponds to the most energetically stable ion....
IR spectroscopy produces an IR spectrum, a plot of intensity versus wavenumber, with peak intensities proportional to concentration. This method has the advantages of being fast while still providing lots of information, and it is sensitive to very small samples. However, applying IR spectroscopy to...
The vibrational predissociation spectrum of the He–HCO + proton bound complex has been recorded in the 3 μm (C–H stretch) region by monitoring the HCO + photofragment current. A rotationally resolved, parallel band is observed, red shifted 12.4 cm 1 from the ν 1 transition of free HCO...
摘要: The band origin, the rotational constants, and the inversion constants of the isotopic ammonia 15NH 3 have been obtained from an analysis of the ν 2 band spectrum around 10 μ. Observed and calculated frequencies are given and compared with those obtained recently from laser spectroscopy....
The infrared spectroscopy (IR) technique refers to energy in the region of the electromagnetic radiation spectrum at wavelengths longer than those of visible light but shorter than those of radio waves. IR region covers a wide range of the electromagnetic spectrum, which is divided into three areas...
X Wang,L Andrews,L Gagliardi - 《Journal of Physical Chemistry A》 被引量: 40发表: 2008年 Microwave, Raman, and far infrared spectra, barrier to internal rotation, and dipole moment of 2,2‐difluoropropane The microwave spectrum of 2,2‐difluoropropane has been investigated in the region ...
The Fourier transform infrared spectrum of acetylene between 2500 cm-1 and 2800 cm-1 has been studied at the Doppler limited resolution of 0·0070 cm-1. The combination band v 2 + v 1 5 and the hot bands (v 2 + 2v 5)2,0 ← v 1 5, v 1 ← v 1 5, v 3 ← v 1 4 and...
Fluorescence imaging in the second near-infrared (NIR-II) window enables deep-tissue imaging with high resolution and improved contrast by taking advantage of the reduced light scattering and tissue autofluorescence in this region of the spectrum. NIR-II fluorescence imaging uses photoluminescent contrast...
FIGURE 51.1.(a) Near-infrared spectrum of Pluto taken with the NASA Infrared Telescope Facility (IRTF). Absorption bands of methane (CH4), carbon monoxide (CO), and nitrogen (N2) ices on the surface of Pluto are shown. (b) Variation in the methane band depth with time and longitude on...
a critical angle of incidence for the light reaching the sample, total internal reflection is obtained. The raw ATR spectrum differs slightly from the transmission spectrum. However, after transformation with a Kubelka–Munk algorithm, the ATR spectrum can be compared with a transmission spectrum. ...