摘要:

The three3JHHcoupling constants observed in the1H NMR spectra (500 MHz) of trioxa-bis-spirocital1and2serve to calculate the dihedral angles Ψ(8,9) and Ψ(9,10) of these two molecules. The values obtained, 54° for1, 25° for2, reflect the change in conformation: chair → crossed ship when passing from1to2.This change in conformation corresponds in13C NMR to strong shielding (−3.6 to −5.5 ppm) of the lines of the carbons C8, C9and C10.

ISSN:0038-7010    

DOI:10.1080/00387018208080885

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

An assignment correlation is described for the13C-nmr chemical shifts of the methylene carbons flanking transoid (E) were in part provided by Grant No. CA 11055 and Contract No. CM-87209 which were awarded by the National Cancer Institute, DHEW. The support of the National Science Foundation, Grant No. CHE-7506162, which provided funds for the acquisition of the XL-100 spectrometer system utilized in the conduct of this research is also gratefully acknowledged.

ISSN:0038-7010    

DOI:10.1080/00387018208080886

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Throughout the optical spectral region from the visible to the far infrared, lasers have in recent years become increasingly important for high resolution spectroscopy in both laboratory measurements and practical applications. In general, laser sources can be classified into broadly tunable and discretely tunable types with the gas laser belonging to the latter. While gas lasers oscillate in narrow lines scattered throughout the optical spectral region, broadly tunable laser emissions cover a range of wide spectral region depending on the lasing media and operating characteristics. For example, the Pb-salt diode laser covers the spectral region from about 2.6 to 30 μm, the dye laser from 400 to 700 nm, the color center laser from 0.8 to 3.3 μm, the difference frequency spectrometer from 2.2 to 4.2 μm and the spin-flip Raman laser from 5.2 to 6.0 μm. The very limited tunability of the gas laser can sometimes be extended to many times the Doppler width by Zeeman tuning the gain medium or pressure broadening the gain profile or electrooptically modulating the laser output frequency with a tunable microwave source.

ISSN:0038-7010    

DOI:10.1080/00387018208080887

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0038-7010    

DOI:10.1080/00387018208080884

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor