Add time:07/22/2019         Source:sciencedirect.com

The dipole moments of four 2,6-dinitrophenyl R'-phenyl (R' = H, 2'-F, 2'-Me and 2'-I), four 2,6 dinitro-4-chlorophenyl R'-phenyl (R' = 2'-F, 2',4'-Cl2, 2'4'-Br2 and 1'-naphthyl) and five 2,4-dinitronaphthyl R'-phenyl (R' = H, 2'-F, 2'-Me, 2'-I, and 2',6',-Me2) ethers have been measured and compared to those calculated for a variety of conformations. In the first two series good agreement was found for the conformation in which the dinitro ring is positioned (i.e. conjugated with the ether oxygen, mesomeric moment 1.2 D) and a nitro group, twisted out of coplanarity, is proximal to the other ring. Good agreement was also found for a conformation in which each ring is twisted 37° from coplanarity in opposite directions and for the structure in which the rings undergo concerted rotation. A similar situation was encountered in the naphthyl series (mesomeric moment equals 1.3 D for a positioned dinitronaphthyl ring) in which, however, of the two possible skew conformations permitted by the positioned dinitro ring, only the one in which the nitro group is proximalto the other ring is consistent with the data. Here, also, a twisted conformation was in good agreement, as well as the concerted rotation. The existence of an electrostatic repulsion between the proximal NO2 group and the 2'-halogen substituents was observed only in the 2,6-dinitrophenyl series, and seemed to outweigh purely steric influences on the preferred conformations.

We also recommend Trading Suppliers and Manufacturers of 2,4-DINITRO-4'-FLUORODIPHENYL ETHER (cas 1033-02-9). Pls Click Website Link as below: cas 1033-02-9 suppliers