Dipole moments of some N-phenyl-substituted derivatives of pyrrolidine, piperidine, morpholine, and thiomorpholine

Abstract

Apparent dipole moments in benzene of various p-substituted N-phenyl derivatives of pyrrolidine, piperidine, morpholine, and thiomorpholine and of some analogous NN-diethylanilines have been determined. Vector moments along the bisector of angle CH2NCH2 and also in the direction of the major axis of the aromatic ring have been calculated for the parent compounds. The order of magnitude of the latter is N-phenylpyrrolidine > NN-diethylaniline > N-phenylpiperidine > N-phenylmorpholine > N-phenylthiomorpholine. The nature of the heterocycle does not greatly affect the additional moment, p(add.), along the major axis of the aromatic ring, required to account for the moments of the p-substituted compounds. In each series of compounds, p(add.

13C-NMR Based Evaluation of the Electronic and Steric Interactions in Aromatic Amines

“…Charge distribution in the molecules of aromatic amines shows the order of electron-donor strength of the amino groups to be (CH 2 ) 4 N > Et 2 N > (CH 2 ) 5 N [50,51] and NEt 2 > N(CH 2 ) 4 > NMe 2 > N(CH 2 ) 5 [50]. The calculated and measured dipole moments confirm the considerable twist of NMe 2 group in ortho-methyl substituted N,N-dimethylanilines [52].…”

Synthesis and chiroptical properties of optically active photochromic methacrylic polymers bearing in the side chain the (S)-3-hydroxypyrrolidinyl group conjugated with thetrans-azoaromatic chromophore

“…In addition, the presence of an electron-donating group, such as the five-membered cyclic pyrrolidinyl moiety directly linked through the nitrogen atom to the azoaromatic system, would yield the possibility of synthesizing polymeric derivatives characterized by the presence of a strongly conjugated donor-acceptor system, upon introducing an electron-withdrawing group in the 4Ј position of the azoaromatic system, potentially suitable for reversible optical storage, chemical photoreceptors, and in general nonlinear optical applications. 5 Chromogens of this type, containing the pyrrolidinyl moiety, are known to exhibit higher values of dipole moment, as observed in 4-nitro dialkyl substituted anilines 6 and in 4-dialkylamino azobenzenes, 7 with respect to the related diethylamino and piperidino derivatives, thus suggesting an increased resonance interaction when the five-membered cyclic amine is conjugated to the aromatic system. In the present article we describe synthesis and characterization of new optically active methacrylic polymers …”

The effects of cyclic terminal groups in di- and tri-arylmethane dyes. Part 3. Consequences of unsymmetrical substitution in Malachite Green

“…The 4-bromo derivatives 13 of N,N-diethylaniline, N-phenylpyrrolidine, N-phenylpiperidine and N-phenylmorpholine were converted into the aryllithium derivatives by reaction with the n-butyllithium-TMEDA complex. 14 The terminal nitrogen atoms of the dyes are at active sites and hence any increase in the electron density at these positions should result in a bathochromic shift of the long-wavelength main absorption band, the magnitude of which will be related to the donating ability of the terminal amino group.…”

“…Melting points were determined in capillary tubes using a Gallenkamp melting point apparatus and are uncorrected. 1 H and 13 C NMR spectra were recorded on a Bruker Advance DPX250MHz multinuclear magnetic resonance spectrometer operating at 250 MHz. The 1 H and 13 C NMR spectra of the dye perchlorates were recorded in acetone-d 6 and coupling constants are given in Hz.…”

“…δ H 1.20 (6H, t, J 6.8, N(CH 2 CH 3 ) 2 ), 2.70 (1H, s, OH), 2.99 (6H, s, N(CH 3 ) 2 ), 3.38 (4H, q, J 6.8, N(CH 2 CH 3 ) 2 ), 6.64 (2H, d, J 8.9, 3-H, 5-H), 6.71 (2H, d, J 8.9, 3Ј-H, 5Ј-H), 7.11 (2H, d, J 8.9, 2Ј-H, 6Ј-H), 7.18 (2H, d, J 8.9, 2-H, 6-H), 7.30-7.37 (5H, m, Ar). δ C 13 4-Diethylamino-4Ј-morpholinotriphenylmethanol 4d. From 4-diethylaminophenyllithium and 4-morpholinobenzophenone as a yellow powder (75%), mp 131-132 ЊC, after recrystallisation from light petroleum (bp 60-80 ЊC).…”