International Journal of Chemical Studies
Vol. 6, Issue 2 (2018)
N, N-(Dialkylsubstituted)-1,2-Diarylethylene Diamines: Chemical Ionization Mass Spectral Analysis
Author(s): Kesamreddy Ranga Reddy, Emani Vijayabhaskar Reddy, Nadim Saade and John F Harrod
Abstract: The chemical ionization mass spectra of a series of vicinal diamines (N,N,N’,N’- tetraalkyl-1,2-diarylethylenediamines), Ar = Phenyl, or substituted phenyl, (1 to 46), synthesized by a novel reductive coupling of N,N-dialkyl benzamides in the presence of organosilane and Titanium have been recorded. Accurate mass measurements were used to confirm the identity of the principal fragmentation products. It is proposed that the primary fragmentation pathway originates from an initial C(1)-C(2) bond cleavage (α-cleavage) with charge retention on the nitrogen atom of one of the fragments, followed by sequential loss of two molecules of methane (R1R2 = Me2) or ethylene (R1,R2 = Et2). This fragmentation pathway initially leads to a stabilized benzylidene dialkylimonium ion, which constitutes the base peak in the spectra of all of the studied compounds, except for the case of R1R2 = Ph(Me), where the base peak arises from the unimolecular deamination of [M+H]+. The relative importance of the two principal fragmentation pathways depends strongly on the nature of the substituents on the aryl group, as also do the subsequent fragmentations. Spectra were recorded for both the meso- and rac- isomer of each compound and only minor differences were observed between the spectra of the two diastereoisomers
Pages: 156-165 | 603 Views 14 Downloads
How to cite this article:
Kesamreddy Ranga Reddy, Emani Vijayabhaskar Reddy, Nadim Saade, John F Harrod. N, N-(Dialkylsubstituted)-1,2-Diarylethylene Diamines: Chemical Ionization Mass Spectral Analysis. Int J Chem Stud 2018;6(2):156-165.