Vibrational Spectra and Normal Coordinate Calculations of Chlorophosphazene Compounds. III. Polydichlorophosphazene

1982 ◽  
Vol 36 (3) ◽  
pp. 277-281 ◽  
Author(s):  
M. M. Coleman ◽  
J. Zarian ◽  
P. C. Painter

Vibrational spectra and normal coordinate calculations of polydichlorophosphazene (PDP) are presented. The valence force field derived previously from the two conformers of octachlorocyclotetraphosphazene was directly transferred to a distorted “cis-plan” helical model of PDP without refinement. A reasonable agreement between the observed and calculated frequencies was obtained and the assignment of the normal modes of PDP is discussed.

1982 ◽  
Vol 36 (3) ◽  
pp. 272-277 ◽  
Author(s):  
J. Zarian ◽  
P. C. Painter ◽  
M. M. Coleman

Vibrational spectra and normal coordinate calculations of octachlorocyclotetraphosphazene (OCTP) are presented. A common valence force field for the two conformers (T and K forms) of OCTP has been developed. A good agreement between the observed and calculated frequencies of OCTP was obtained and the assignments of the normal modes are discussed.


1982 ◽  
Vol 36 (3) ◽  
pp. 265-271 ◽  
Author(s):  
P. C. Painter ◽  
J. Zarian ◽  
M. M. Coleman

Vibrational spectra and normal coordinate calculations of hexachlorocyclotriphosphazene (HCTP) are presented. Attempts to obtain a common valence force field for HCTP and the two conformers of octachlorocyclotetraphosphazene which were not successful, are discussed. The force field obtained for HCTP is, by necessity, relatively simple. Nevertheless, we have been able to make assignments of the normal modes and resolve some apparent discrepancies in the literature.


1971 ◽  
Vol 49 (18) ◽  
pp. 2931-2936 ◽  
Author(s):  
J. W. Anderson ◽  
G. K. Barker ◽  
J. E. Drake And ◽  
R. T. Hemmings

The infrared and Raman spectra of the series of iodo(methyl)germanes, CH3GeI3, (CH3)2GeI2, and (CH3)3GeI have been recorded. A normal coordinate analysis based on a modified valence force field confirms the a priori assignments for all of the fundamental frequencies except the torsional modes.


1981 ◽  
Vol 59 (19) ◽  
pp. 2909-2920 ◽  
Author(s):  
John E. Drake ◽  
Boris M. Glavinčevski ◽  
Layla N. Khasrou

Methylthiosilanes of the type (CH3)nH3−nSiSCH3, n = 0–3, and (CH3)HSi(SCH3)2 have been prepared. Their ir and Raman spectra were recorded and assigned. The assignments were supported by normal coordinate analyses based on a modified valence force field.


1993 ◽  
Vol 48 (1) ◽  
pp. 44-47 ◽  
Author(s):  
W. Preetz

By ligand exchange reactions of (n-Bu4N )[ReOBr4] with NaI dissolved in acetone pure (n-Bu4N )[ReOI4], and with AgSCF3 suspended in dichloromethane (n-Bu4N )[ReO(SCF3)4] have been prepared for the first time. The vibrational spectra of both complexes are assigned according to point group C4v, supported by normal coordinate analysis based on a general valence force field. 13C and ,19F NMR spectra provide evidence for the equivalence o f the SCF3 groups.


1989 ◽  
Vol 44 (10) ◽  
pp. 1214-1220 ◽  
Author(s):  
P. Erlhöfer ◽  
W. Preetz

Normal coordinate analyses for all compounds of the two series Cs2[PtF„35Cl6-n] and Cs2[PtF„37Cl6-n], n = 0-6, including the geometric isomers for n = 2, 3, 4 have been performed, based on a general valence force field. The excellent agreement of calculated and observed frequencies confirms the assignments of the vibrational spectra. Due to the stronger trans influence of Cl compared to F in all asymmetric F–Pt–Cl axes the Pt–Cl bonds are strengthened and the Pt–F bonds are weakened, as indicated by valence force constants for Pt–Cl approximately 20% higher, for Pt–F 20% lower, compared with the values calculated for symmetric Cl–Pt–Cl and F–Pt–F axes, respectively. The contour of the Raman line ν2 (Eg, Oh) of Cs2[PtCl6] is explained by the superposition of the calculated spectra for the six most frequent isotopomers Cs2[Pt35Cln37Cl6-n] present in mixtures with natural abundance of Cl isotopes (75,53% 35Cl, 24,47% 37Cl) by statistical distribution on the octahedron sites.


1974 ◽  
Vol 52 (14) ◽  
pp. 2590-2602 ◽  
Author(s):  
Christian Destrade ◽  
Eliane Dupart ◽  
Monique Joussot-Dubien ◽  
Chantal Garrigou-Lagrange

The valence force field and normal modes of vibration of α-glycylglycine have been calculated using the vibrational spectra of ten isotopic derivatives, selectively labeled with deuterium or nitrogen-15. It is shown that this force field permits the determination of the frequencies of glycylglycine-hydrochloride in the solid state, despite a structure very different from that of the zwitterion. The agreement is particularly satisfying for those modes of vibration most sensitive to molecular conformation. It is thus possible to use this type of calculation to determine the conformation of an oligopeptide.


1992 ◽  
Vol 47 (12) ◽  
pp. 1667-1672 ◽  
Author(s):  
W. Preetz ◽  
M. Manthey

The IR and Raman spectra of the ten bromo-iodo-osmates(IV) [OsBrnI6-n]2-, n = 0-6, including the geometrical isomers for n = 2, 3, 4, have been recorded at low temperature. The vibrational spectra are completely assigned according to point groups Oh, D4h, C4v, C3v, and C2v, as supported by normal coordinate analyses based on a general valence force field. Due to the different trans-influences Br<I in asymmetric axes Br′–Os–I′, the Os–I′ bonds are strengthened and the Os–Br′ bonds are weakened, as indicated by valence force constants, for Os–I′ on average 4% higher and for Os–Br′ 4% lower, as compared with the values calculated for symmetric I–Os–I and Br–Os–Br axes, respectively.


1977 ◽  
Vol 30 (9) ◽  
pp. 1905 ◽  
Author(s):  
CG Barraclough ◽  
GE Berkovic ◽  
GB Deacon

The Raman spectra of phenylmercuric chloride, phenylmercuric bromide, phenylmercuric iodide and diphenylmercury, and the infrared and Raman spectra of diphenylmercury in solution are reported. Using the previously reported infrared spectra of these compounds, vibrations were assigned, normal coordinate analyses were performed and frequencies were calculated using a valence force field. Good agreement was achieved between observed and calculated frequencies. The structure of diphenyl-mercury in solution is discussed.


1994 ◽  
Vol 49 (6) ◽  
pp. 753-758 ◽  
Author(s):  
P. Prillwitz ◽  
W. Preetz

The IR and Raman spectra of the ten bromo-iodo-rhenates(IV) [ReBrnI6-n]2-, n = 0 -6 , including the geometrical isomers for n - 2,3,4, have been recorded at 80 K. The vibrational spectra are completely assigned according to point groups Oh, D4h, C4v, C3v, and C2v, as supported by normal coordinate analyses based on a general valence force field. Due to the different mms-influences Br < I in asymmetric axes Br•-Re-I', the Re-I' bonds are strengthened and the Re-Br• bonds are weakened, as indicated by valence force constants, for Re-I' on average 8,5% higher and for Os-Br• 8,3% lower, as compared with the values calculated for symmetric I-Re-I and Br-Re-Br axes, respectively


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