ISSN:
0021-8383
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Hammett Relationships between 1H-NMR and 31P-NMR Chemical Shifts, Respectively, and Substituent Constants in ω-Diphenylphosphinyl and ω-Diphenylthiophosphinyl trans-StyrenesA well linear correlation between the chemical shifts of the ethylenic protons HB and the 31P nuclei, respectively, and the Hammett constants σp of substituents R in 4-position for diphenylphosphinyl trans-styrenes 1 and the analogous diphenylthiophosphinyl trans-styrenes 2 has been found. A similar relationship for the proton HA has been observed in the case of 1 only, but the substituent-induced shifts are not so sensitive. Donor substituents R in 1 and 2 effect an increase in the shielding of HB and a deshielding of the P atom being connected with shifts of the i. r. P=O absorption bands in 1 in the direction of lower wavenumbers. A mesomeric interaction between R and P=Y substituents (Y = O, S) is concluded to produce polymethin-like π-electron density distribution.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19833250213
