Characteristic vibrations of —N(CH₃)₂and —N⁺(CH₃)₃groups in dimethyl aminophenols and their methiodides

Abstract

From an analysis of the infrared spectra of dimethylaminophenols and their methiodides, along with their -N(CD3), and -N+(CD3)3 derivaties, the characteristic absorptions of the -N(CH3)2 and -N+(CH3)3 groups have been assigned. Strong absorptions near 950 cm-', generally ascribed to C-N stretching modes in a large number of compounds containing the -N+(CH3)3 group, have been found to arise from CH3 rocking modes. EXPERIMENTALTrimethyl sulphoxonium iodide was prepared l7 by refluxing dimethyl sulphoxide with 2.25 times the stoichiometric amount of methyl iodide for 4 days. I t was deuterated thrice with D20 (99.8 %) in the presence of sodium carbonate. [2H,]Methyl iodide obtained by

Functionalization of poly(bis‐thiophene methine)s via facile C–C bulk polymerization and their application as chemosensors for acid detection

“…All polymers have peaks around 1446 and 1259 cm −1 originated from the stretching of CC and C–C in the thiophene ring with the observation of peaks around 698 cm −1 related to in‐plane deformation of C–S–C of thiophene ring . Meanwhile, most polymers show distinct strong sharp peaks at 2950, 2925, and 2854 cm −1 , which are assigned to CH 3 , CH 2 , or CH stretching modes . In addition, P6 containing the NO 2 group shows NO symmetrical stretching and asymmetric stretching modes at 1357 and 1518 cm −1 respectively.…”

“…66 Meanwhile, most polymers show distinct strong sharp peaks at 2950, 2925, and 2854 cm 21 , which are assigned to CH 3 , CH 2 , or CH stretching modes. 67 In addition, P6 containing the NO 2 group shows N@O 68 symmetrical stretching and asymmetric stretching modes at 1357 and 1518 cm 21 respectively.…”

Adsorptive Removal of Azo Dye New Coccine Using High-Performance Adsorbent-Based Polycation-Modified Nano-Alpha Alumina Particles

“…Lately, the S � O vibration at 1173 and 1144 cm −1 and the symmetrical −SO 3 stretching vibration at 1040 cm −1 of the NCC molecule disappeared in the PVBTAC-modified α-Al 2 O 3 spectrum [43][44][45]. In addition to that, the R 3 N + -C vibration at 1800-3400 cm −1 and C-N peak at 976 cm −1 of PVBTAC in the spectrum of NCC-adsorbed-PVBTACmodified α-Al 2 O 3 [41,42] were absent, strongly confirming the electrostatic attractions between −SO 3 of NCC and −N + R 3 of PVBTAC. At the optimal pH 8 and NaCl 10 mM, the −OH group in the NCC was partly transferred to OH + 2 as the pK a is 11.38 [46], reducing its total negative charges as well as the electrostatic repulsion between the NCC molecules.…”

“…e sharp peak at 1051 cm −1 presenting for the Al-OH vibration of the α-Al 2 O 3 moved to 1059 cm −1 in the PVBTAC-modified α-Al 2 O 3 spectrum. Besides, R 3 N + -C vibration arose at 1853, 2924, 3050, and 3360 cm −1 and especially, a strong band at 976 cm −1 assigned to C-N + R 3 in the PVBTAC spectrum, disappeared in the PVBTAC-modified α-Al 2 O 3 particle spectrum [41,42].…”

Raman spectra of the III → II phase transition in normal (d0) and deuteriated (d12) tetramethylammonium chlorides

“…The infrared spectra of the deuteriated ( d12) tetramethylammonium ion at room temperature have also been reported by Berg' and Agashe and Jose. 4 We report here the Raman spectra of polycrystalline TMAC-d12 in phases I11 and 11.…”