Anharmonic Stretch–Stretch Interaction Force Constants of Triatomic Molecules

1969 ◽  
Vol 50 (10) ◽  
pp. 4429-4436 ◽  
Author(s):  
Katsunosuke Machida ◽  
John Overend
Keyword(s):  
Interaction Force ◽  
Force Constants ◽  
Triatomic Molecules

Unlike pair potential interaction force constants for hydrogen-light hydrocarbon systems

AIChE Journal ◽  
1975 ◽  
Vol 21 (1) ◽  
pp. 173-175 ◽  
Author(s):  
T.-C. Chu ◽  
Patsy S. Chappelear ◽  
Riki Kobayashi
Keyword(s):  
Pair Potential ◽  
Interaction Force ◽  
Potential Interaction ◽  
Light Hydrocarbon ◽  
Force Constants

scholarly journals On the relation between the form, force constants, and vibration frequencies of triatomic systems

1936 ◽  
Vol 156 (889) ◽  
pp. 654-678 ◽  
Keyword(s):  
Force Constants ◽  
Critical Survey ◽  
Vibration Frequencies ◽  
Triatomic Molecules ◽  
Fundamental Frequencies ◽  
General Potential ◽  
Experimental Side ◽  
Theoretical Evidence ◽  
The Right ◽  
High Degree

Within the past few years extensive contributions have been made to our knowledge of the architecture of polyatomic molecules. The some what indefinite bond diagrams of the chemists have been rep;aced by a more precise stereo-chemistry in which inter-atomic distances and valency angles are known with considerable accuracy. Most of this advance has come from the experimental side, particularly from vibration spectra and X-ray and electron diffraction measurements, but some progress has also been made on the purely theoretical side. For reasons of simplicity, attention up to the present has been mainly confined to two classes of molecule, namely those which possess a high degree of symmetry, e. g ., CH 4 , C 2 H 2 , and those which contain only three atoms, e. g ., SO 2 . There are, however, so many molecules belonging to the second of these classes that a detailed study of them alone is well worth while. It is the purpose of the present paper to make a critical survey of the experimental evidence on the shapes and fundamental frequencies of a number of triatomic molecules by studying the variations in the force constants from molecule to molecule. Our procedure is as follows. We begin by making a list of all the triatomic molecules and ions on which there is any experimental or theoretical evidence as regards size, shape, and vibration frequencies. These we divide roughly into three categories, "certain", "less certain", and "doubtful", and use the results on the first of these to guide us in dealing with the others. There is naturally no difficulty about evaluating the force constants for the molecules which are "certain"; in fact, for some of these various authors have already calculated all the force constants in the most general potential function of second degree consistent with the symmetry of the molecule. The present calculations, of course, do not aim at such accuracy as this because in most cases the data are not sufficient. We are more concerned with discovering whether the fundamental frequencies have been correctly assigned and whether we have adopted the right shape for the molecule.

Carbonyl stretching frequencies and force constants in cyclopentadienylmolybdenum tricarbonyl derivatives

1969 ◽  
Vol 47 (16) ◽  
pp. 2959-2964 ◽  
Author(s):  
R. B. King ◽  
L. W. Houk
Keyword(s):  
Infrared Spectra ◽  
Interaction Force ◽  
Force Constants ◽  
Alkyl Groups

The infrared spectra of compounds of the type RM(CO)3C5H5 (M = Mo or W; R = (CH3)3Sn, σ-alkyl groups, halides, etc.) exhibit the expected three v(CO) frequencies (2A′ + A″). The relative positions of the A″ and the lower A′ frequencies interchange upon variation of the electronegativity of the R group. Values for the Cotton–Kraihanzel stretching force constants k1 and k2 have been calculated from these v(CO) frequencies assuming the ratio kd/ks = 2 for the interaction force constants. From these force constants the σ and π parameters of Graham were calculated. The σ and π parameters were found to be very similar for analogous RM(CO)3C5H5 and RMn(CO)5 compounds.

scholarly journals The Raman spectra of Bis(hexamethylenetetramine)-iodine(I) and -bromine(I) perchlorates

1977 ◽  
Vol 30 (5) ◽  
pp. 1123 ◽  
Author(s):  
GA Bowmaker ◽  
RJ Knappstein
Keyword(s):  
Raman Spectra ◽  
Halogen Bond ◽  
Interaction Force ◽  
Force Constants ◽  
Bond Stretching

The low-wavenumber (<200 cm-1) Raman spectra of bis(hexamethylenetetramine)iodine(I) perchlorate and bis(hexamethylenetetramine)bromine(I) perchlorate have been measured, and the nitrogen-halogen symmetric stretching mode of the cation has been assigned for each compound. The nitrogen-halogen bond stretching and interaction force constants for the cations have been calculated, and these are found to be very similar to those for the corresponding bis(pyridine)halogen(I) cations.

Force Constants of Triatomic Molecules

1945 ◽  
Vol 13 (10) ◽  
pp. 388-396 ◽  
Author(s):  
Geo. Glockler ◽  
Jo‐Yun Tung
Keyword(s):  
Force Constants ◽  
Triatomic Molecules

Zur Stereochemie von Diazadien-Metall-Komplexen, V. Molekülstrukturen und CO-Kraftkonstanten nicht-starrer Chrom-, Molybdänund Wolframcarbonylderivate DAD M(CO)3(*CO) (*C0 = 12CO, 13CO, C180)/ Stereochemistry of Diazadiene Metal Complexes, V Molecular Structures and CO Force Constants of Non-Rigid Chromium, Molybdenum and Tungsten Carbonyl Derivatives DAD M(CO)3(*CO) (*CO = 12CO, 13CO, C18O)

1983 ◽  
Vol 38 (5) ◽  
pp. 568-579 ◽  
Author(s):  
Heindirk tom Dieck ◽  
Thomas Mack ◽  
Karl Peters ◽  
Hans-Georg von Schnering
Keyword(s):  
Force Constant ◽  
Good Accuracy ◽  
Interaction Force ◽  
Force Constants ◽  
Molecular Structures ◽  
X Ray ◽  
Carbonyl Derivatives ◽  
Donor Acceptor ◽  
Site Exchange ◽  
Ray Methods

AbstractDiazadiene metal tetracarbonyls, DAD M(CO)4, (M = Cr, Mo, W; DAD = R-N = CH-CH = NR with aliphatic and aromatic substituents R) show equidistribution of one labelled CO when synthesized from fac-DAD M(CO)3(CH3CN) as a consequence of intramolecular CO site exchange. The structures of two Mo-complexes (1: R = iso-propyl; 2: R = 2,6-diisopropylphenyl) with DAD's of different bulkiness have been solved by X-ray methods. From the infrared solution spectra, including those of isotopically labelled (13CO, C18O) compounds, all of the force constants k1, k2, ktt, kcc and kcc have been calculated independently. The ratios of interaction force constants deviate sharply from Cotton-Kraihanzel assumptions, perhaps because of the substantial deviation of the iraws-pair of CO groups from linearity (1: 154.5°, 2: 147.9°). The solid state N-Mo, Mo-C and C - O bond lengths are neither in agreement with the generally accepted picture for donor/acceptor influences nor with typical IR data and force constant interpretations. (2 with higher v(CO) and k1, k2 has the longer CO bonds and shorter Mo-C bonds than 1.) The force constant sets have been used to calculate CO frequencies for over 60 labelled compounds with good accuracy (Δv < 2 cm-1).

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