Coriolis interaction between the ν7+ν8 and ν4+ν8 bands of 13C2D4 by high-resolution FTIR spectroscopy

The infrared spectra of two B type bands, ν2 and 2ν1, of 14N16O2 have been recorded under high resolution. Ground state combination differences from these bands have been combined with combination differences obtained in previous studies and eight pure rotational microwave transitions to yield improved ground state rotational constants. Upper state constants and band centers for the ν2 and 2ν1 bands are also reported. The 2ν1 band contains internal intensity anomalies believed to arise from a weak Coriolis interaction with the much stronger ν1 + ν3 band. Equilibrium rotational constants have been calculated. The equilibrium structure of the molecule is: rc = 1.1945 ± 0.0005 Å and Θc = 133.85 ± 0.10°. For the sake of comparison, effective, substitution, and average structures are also reported.

Download Full-text

Measurement of the variation of crystal lattice structures of ethylene copolymers with high-resolution cryogenic FTIR spectroscopy

Journal of Applied Polymer Science ◽

10.1002/app.33825 ◽

2011 ◽

Vol 121 (4) ◽

pp. 2072-2077

Author(s):

Zhiqiang Su ◽

Qing Li ◽

Li Cao ◽

Xiaonong Chen

Keyword(s):

High Resolution ◽

Crystal Lattice ◽

Ftir Spectroscopy ◽

Lattice Structures ◽

Ethylene Copolymers

Download Full-text

Structure of poorly-ordered aluminosilicates

Clay Minerals ◽

10.1180/claymin.1986.021.5.03 ◽

1986 ◽

Vol 21 (5) ◽

pp. 879-897 ◽

Cited By ~ 22

Author(s):

M. A. Wilson ◽

S. A. McCarthy ◽

P. M. Fredericks

Keyword(s):

Electron Microscopy ◽

Nuclear Magnetic Resonance ◽

Fourier Transform ◽

Solid State ◽

Nmr Spectroscopy ◽

Magnetic Resonance ◽

High Resolution ◽

Ftir Spectroscopy ◽

Driving Forces ◽

Repulsive Forces

AbstractThe structure of synthetic aluminosilicates prepared at pH 6 has been investigated by 29Si and 27Al high-resolution solid-state nuclear magnetic resonance (NMR) spectroscopy. Fourier transform infrared (FTIR) spectroscopy and electron microscopy have also been used to characterize the products. The amount of Si and Al in protoimogolite, disordered allophane and other structures has been measured. There is a fair correlation between the intensity of the 349 cm−1 band in the FTIR spectra and the proportion by weight of protoimogolite Si measured by NMR. It is shown that disordered allophanes have similar structures to those proposed by van Reeuwijk and de Villiers (Soil Sci. Soc. Am. Proc. 32 (1968) 238–240), i.e. octahedral Al surrounding a tetrahedral core. Moreover, it is clear that at high Al:Si ratios (⩾1:1), protoimogolite can compete with disordered allophane precursors for aluminum. The driving forces for formation of protoimogolite rather than allophane appear to be long range Al-Al repulsive forces through oxygen.

Download Full-text