The vibrational spectra of 4-pyridone, and its 2,3,5,6-tetradeutero, N-deutero, N-methyl, N-cyano, and 3,5-dihalogeno derivatives. Mixing between C=C and C=O stretching vibrations

1969 ◽  
Vol 22 (12) ◽  
pp. 2581 ◽  
Author(s):  
BD Batts ◽  
E Spinner

The infrared spectra of the above compounds, and the Raman spectra of the parent compound and its 2,3,5,6-D4, 1-D, and 1-Me derivatives have been determined. The effects of electron-withdrawing substituents, N- methylation, and deuteration on the two intense infrared bands in the 1480-1650 cm-1 region are not compatible with one being a C=O and the other a C=C stretching band. These two vibrations must be extensively mixed; occasionally very pronounced medium effects, which are not straightforward, are observed for one or both of these bands. The spectra are not in accord with a mostly zwitterionic (N-protonated pyrid-4-oxide) structure (II) of 4-pyridone. Band assignments are made for the parent compound.

1971 ◽  
Vol 24 (5) ◽  
pp. 911 ◽  
Author(s):  
JR Hall ◽  
BE Smith

The Raman spectra of cyclopentadienyltrimethylplatinum(IV) in the solid state and solution have been recorded and interpreted in conjunction with the corresponding infrared spectra over the range 4000-30 cm-1. Assignments have been made on the basis of local symmetry. Polarized Raman lines at 561 and 263 cm-1 have been assigned to symmetric Pt-CH3 stretching and Pt-cp stretching vibrations respectively. The spectral data are consistent with a pentahapto π-bonded cp ring.


1990 ◽  
Vol 55 (6) ◽  
pp. 1485-1490 ◽  
Author(s):  
Peter Schwendt ◽  
Milan Sýkora

The infrared and Raman spectra of M2[V2O2(O2)4(H2O)]·xH2O and M2[V2O2(O2)4(D2O)]·xD2O (M = N(CH3)4, Cs) were measured. In the region of the vanadium-oxygen stretching vibrations, the spectra were interpreted based on normal coordinate analysis, employing empirical correlations between the bond lengths and force constants.


1956 ◽  
Vol 34 (2) ◽  
pp. 170-178 ◽  
Author(s):  
K. Ito ◽  
H. J. Bernstein

The infrared spectra of the formate, acetate, and oxalate ions have been obtained for both the solid and aqueous solution. The Raman spectra of these ions with depolarization ratios have been obtained in aqueous solution. Vibrational assignments have been made which differ slightly for the acetate ion and more markedly for the oxalate ion from earlier work. The depolarization ratios confirm Fonteyne’s assignment for the formate ion.


1988 ◽  
Vol 43 (10) ◽  
pp. 1327-1331 ◽  
Author(s):  
A Heinrich ◽  
W Preetz

Treatment of B6H62- with iodoalkanes and (SCN)2 in organic solvents affords the monosubstituted protonated hexaborates RB6H6-, R = CH3, C2H5< C3H7, C4H9, C8H17 and SCN, respectively. The acidity constants of these weak Brönsted acids range for the alkylated species from 8.8 to 9.6, and for R = SCN the pka value is ~5. From basic solutions the salts Cs2RB6H5 can be precipitated, which show band patterns in the IR and Raman spectra typical for monosubstituted hydrohexaborates. The protonated compounds RB6H6- are distinguished from the corresponding Brönsted bases RB6H52- by a high frequency shift of the BH stretching vibrations in the order of 100 cm-1. For Cs2(SCN)B6H5, S coordination of SCN- is supposed because of the high frequency of νCN: 2144 cm-1.


1979 ◽  
Vol 32 (7) ◽  
pp. 1443 ◽  
Author(s):  
GA Bowmaker ◽  
L Tan

A number of different methods for preparing anionic Group 1B metal thiolate complexes have been investigated. The compounds [Me4N] [CU2(SMe)3] and [Et4N] [Ag5(SBut)6] are reported for the first time, and new methods for preparing the previously known compounds [Et4N] [Cu5(SBut)6], [Me4N]2 [CU5(SPh)7] and [Et4N]2 [Cu5(SPh)7] are described. The far-infrared spectra of the above compounds, and of CuSMe, CuSBut, AgSBut, [Me4N]2 [CU4(SPh)6] and [Me4N]2 [Ag5(SPh)7] have been obtained, and metal-sulfur stretching bands are assigned in the 150-350 cm-1 region. The low-frequency Raman spectra have also been obtained for some of these compounds. Possible structures for the new compounds are considered in the light of the low-frequency vibrational spectra.


1969 ◽  
Vol 23 (3) ◽  
pp. 224-229 ◽  
Author(s):  
Umesh Agarwala ◽  
P. Bhaskara Rao

The infrared spectra of substituted acetylacetonates have been discussed in the light of normal coordinate analysis of bis-(monothioacetylacetonato) Ni(II) assuming methyl groups as point masses. The Urey-Bradley potential constants evaluated are found to be quite close to those of analogous systems studied earlier. The calculations show that each of the fundamental bands results from vibrational modes involving appreciable contributions from a number of bonds. The single major contribution from the stretching of C = S has been found in the 723 cm−1 band. This is in agreement with the other conjugated systems, like thioamides, studied earlier.


1974 ◽  
Vol 29 (9-10) ◽  
pp. 647-653 ◽  
Author(s):  
Hans Bürger ◽  
Reint Eujen

The IR and Raman spectra of SiH3⊖, SiH3SiH2⊖, (SiH3)2SiH⊖, (SiH3)3Si⊖ and their deuterated derivatives have been recorded in HMPT and HMPT-d18 solutions. Most normal vibrations have been identified. The SiH and SiSi stretching vibrations are considerably lower than for analogous silanes and silylphosphines, ∼ 2050 and 1850-1900 cm-1 being characteristic for SiH3 and SiH⊖n groups respectively. The assignments are proved by a normal coordinate analysis, and force constants have been calculated. The negative charge is mainly localized on the trivalent Si atom and the lone pair acts repulsively rather than strengthening the SiSi bond through (p→d)π effects.


1970 ◽  
Vol 48 (5) ◽  
pp. 838-844 ◽  
Author(s):  
P. M. Boorman ◽  
P. J. Craig ◽  
T. W. Swaddle

The Raman and low-frequency infrared spectra of the trigonal-bipyramidal complexes Co(RNC)5ClO4(R = Me, Et, Ph) have been recorded and assigned. It is found that δ(CoCN) modes occur at higher frequencies than ν(Co—CN) modes. Although Raman spectra of the blue and yellow forms of Co(PhNC)5(ClO4)2 could not be obtained, the low-frequency infrared spectra are consistent with the C4v structure previously suggested (1). The dimeric complexes Co2(RNC)10(ClO4)4 (R = Me, Et) have been studied, and tentative assignments of the Raman and infrared spectra made on the basis of D4d symmetry. Spectra of the complexes Co2(RNC)10I(ClO4)3 (R = Me, Et) strongly support the previously suggested structural formulation (2) [(MeNC)5Co—I—Co(MeNC)5](ClO4)3, and furthermore indicate that the Co—I—Co skeleton is linear.


1977 ◽  
Vol 31 (3) ◽  
pp. 230-236 ◽  
Author(s):  
R. N. Bhargava ◽  
R. A. Condrate

Infrared and Raman spectra were measured and interpreted for two crystalline VPO5 phases (α- and β-VPO5) and several related vanadium phosphate glasses. The spectral results for the crystalline phases were consistent with those predicted by factor group analysis using the previously determined space groups. Empirical band assignments were made for the observed bands on the basis of the bands observed earlier for related phosphate and oxyvanadium compounds. Also, the band assignments made for the infrared spectra of the glasses were consistent with the assignments for crystalline V2O5 and the two crystalline VPO5 phases. No Raman spectra were observed for the glasses because processes involving adsorption and Rayleigh scattering dominated over Raman scattering. The infrared spectra of vanadium phosphate glasses with high P2O5 concentrations possessed many features resembling those observed in the infrared spectra of α-VPO5, suggesting similarities in the short range order for the two materials. Analyses of the vibrational spectra of hydrated α-VPO5 samples suggests that the water molecules are adsorbed in the interlamellar spaces of the crystals, complexing to vanadium ions. Initial steps in the hydration of vanadium phosphate glasses apparently involve physical adsorption of water on their surfaces. No water adsorption could be detected for β-VPO5 under normal conditions from its infrared and Raman spectra.


1970 ◽  
Vol 48 (19) ◽  
pp. 3089-3094 ◽  
Author(s):  
P. J. Craig

Raman and infrared spectra of a series of complexes RCOMo(CO)2[L]π-C5H5 (R = Me, Et, σ-C3H5, CH2Ph; L = PPh3, P(OCH2)3CCH3) and of ClMo(CO)2[PPh3]π-C5H5 and HW(CO)2[P(OPh)3]π-C5H5 have been recorded. In this complementary study of complex metal carbonyl compounds, assignments are suggested for metal–carbon–oxygen deformation, metal–carbon stretching, metal–ring, and metal–phosphorus stretching vibrations. It is thought that the latter occur in the range 240–200 cm−1, frequencies for phosphite complexes being lower than for the corresponding phosphine derivatives.


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