scholarly journals Infrared Band Shape of the C–I Stretching Vibration of Methyl Iodide in Solutions

1975 ◽  
Vol 48 (12) ◽  
pp. 3464-3468 ◽  
Author(s):  
Kenji Fujiwara ◽  
Kohji Fukushi ◽  
Shun-ichi Ikawa ◽  
Masao Kimura
Keyword(s):  
Methyl Iodide ◽  
Infrared Band ◽  
Band Shape ◽  
Stretching Vibration

ChemInform Abstract: INFRARED BAND SHAPE OF THE CARBON-IODINE STRETCHING VIBRATION OF METHYL IODIDE IN SOLUTIONS

1976 ◽  
Vol 7 (11) ◽  
Author(s):  
KENJI FUJIWARA ◽  
KOHJI FUKUSHI ◽  
SHUN-ICHI IKAWA ◽  
MASAO KIMURA
Keyword(s):  
Methyl Iodide ◽  
Infrared Band ◽  
Band Shape ◽  
Stretching Vibration

Infrared Band-Shape Studies of Sulphate Glasses

1982 ◽  
Vol 37 (2) ◽  
pp. 191-195
Author(s):  
H. G. K. Sundar ◽  
R. Parthasarathy ◽  
K. J. Rao
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Shape Analysis ◽  
Cluster Model ◽  
Deformation Band ◽  
Infrared Band ◽  
Band Shape ◽  
Correlation Times ◽  
Second Moments

Abstract IR band-shape analysis has been carried out on the 620 cm-1 deformation band of the sulphate ion in several Na2SO4-K2SO4-ZnSO4 glasses. Variations of correlation times and second moments suggest that reorientational motions of sulphate ions begin to evolve prior to the glass-transition temperature. The correlation times may support a cluster model for the glass-transition.

scholarly journals Synthesis Of 4-Alil-6- (Hydroxymethyl) -2-Methody Phenol Compounds from Eugenol Through Mannich Reaction Followed Methylation with Methyl Iodide and Subtitution Using NaOH

2019 ◽  
Vol 1 (1) ◽  
pp. 75-85
Author(s):  
Sabarmin Perangin-angin
Keyword(s):  
Nucleophilic Substitution ◽  
Methyl Iodide ◽  
Mannich Reaction ◽  
Substitution Reaction ◽  
Relative Molecular Mass ◽  
Hydroxymethyl Group ◽  
Phenol Compounds ◽  
Ms Analysis ◽  
Stretching Vibration ◽  
Solid Form

Eugenol derivative compound 4-allyl-6-hydroxymethyl-2-methoxy phenol was synthesized through Mannich reaction, methylation, dan nucleophilic substitution. Mannich reaction was carried out by reacting eugenol, formaldehyde 37%, and dimethylamine 40 % in reflux condition with n-heptane solvent at temperature 98o-100oC for 10 hours produced 4-allyl-6-(dimethylamino)methyl-2-methoxy phenol with yield of 83 %. The formation of dimethylaminomethyl group supported by C-N stretching vibration at 1246,16 cm-1 and ion molecule peak at 221 in GC-MS analysis. Methylation of 4-allyl-6-(dimethylamino)methyl-2-methoxy phenol was carried out with methyl iodide in ethanol solvent produced 6-((N-iodo-N-methyl-N-methyl-N-methylamino) methyl)-4-allyl-2-methoxy phenol in solid form, which then purified by recrystallization with 78,15 % yield. 4-allyl-6-(hydroxymethyl)-2-methoxy phenol was synthesized by nucleophilic substitution reaction of 6-((N-iodo-N-methyl-N-methyl-N-methylamino)methyl)-4-allyl-2-methoxy phenol with sodium hydroxide in reflux condition then purified by coloum chromatography gave liquid compound with yield of 65,05%. The formation of hydroxymethyl group supported by OH vibration at 3433,9 cm-1 and ion molecule peak at 194 in GC-MS analysis show the relative molecular mass of synthesized product.

A COMPARISON OF OPTIMIZATION METHODS FOR FITTING CURVES TO INFRARED BAND ENVELOPES

1966 ◽  
Vol 44 (24) ◽  
pp. 3031-3050 ◽  
Author(s):  
J. Pitha ◽  
R. Norman Jones
Keyword(s):  
Least Squares ◽  
Computation Time ◽  
Direct Methods ◽  
Nonlinear Least Squares ◽  
Optimization Methods ◽  
Infrared Band ◽  
Band Shape ◽  
Analytical Functions ◽  
Degree Of Convergence ◽  
Better Than

A comparison has been made of seven numerical methods of fitting infrared absorption band envelopes with analytical functions using nonlinear least squares approximations. Gauss and Cauchy (Lorentz) band shape functions are used, and also sum and product combinations of the two. The methods have been compared with respect to both the degree of convergence and to the computation time needed to achieve an acceptable fit.The most effective method has matched the overlap envelope of a steroid spectrum containing 16 bands; this necessitated the optimization of 65 variables. More complex spectra can be dealt with by a "moving subspace" modification in which only the parameters of a group of adjacent bands are adjusted at one time. Automatic computer programs have been written for five of the methods, and for the moving subspace modification. These will be published elsewhere.If the computed curve is convoluted with the spectral slit function before making the least squares calculations, the distortion of the observed spectrum caused by the finite spectral slit width can be corrected. In some cases this method of diminishing the slit distortion is better than direct methods, particularly when dealing with strongly overlapped bands.

Hydrogen bonding in the vapour phase: an unusual type of infrared band

1970 ◽  
Vol 316 (1526) ◽  
pp. 303-313 ◽  
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Chloride ◽  
Near Infrared ◽  
Low Frequency ◽  
Vapour Phase ◽  
Infrared Band ◽  
Deuterium Chloride ◽  
Near Infrared Spectra ◽  
Bending Mode ◽  
Stretching Vibration

Association bands, due to vibrations of the hydrogen halides modified by hydrogen bonding, have been measured in the near infrared spectra of mixtures of alkyl cyanides with hydrogen chloride or deuterium chloride in the vapour phase. The vibration frequencies of the hydrogen bonds have been estimated. The association band found with mixtures of methyl cyanide and hydrogen chloride, or deutero derivatives of each of these molecules, shows a broad contour upon which a number of sharp peaks are superposed at the lower frequency side. These peaks have been interpreted as being due to an agglomeration of P lines near the band head in each of a series of hot bands which accompany the association band, and which arise from transitions from higher levels of a bending mode of low frequency. The latter appears to have a frequency in the range 20 to 60 cm -1 . The spectral analysis suggests that the excitation of the hydrogen halide stretching vibration leads to a shortening of the hydrogen bond.

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