Showing papers in "Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy in 1970"
TL;DR: In this paper, the infrared spectra of phthalocyanine and seven divalent metal derivatives have been recorded in the region 400-4000 cm−1 and the metal-ligand vibration and other metal dependent bands were found and the anomalies of Cu2+ and Zn2+phthalocyanines were interpreted on the basis of electronic configurations of outer orbitals of the metals.
Abstract: The infrared spectra of phthalocyanine and seven divalent metal derivatives have been recorded in the region 400–4000 cm−1. The metal-ligand vibration and other metal dependent bands were found and the anomalies of Cu2+ and Zn2+-phthalocyanines were interpreted on the basis of electronic configurations of outer orbitals of the metals.
125 citations
TL;DR: In this article, the infrared and Raman spectra of dimethylsulfoxide and dimethyl sulfoxide-d 6 have been re-investigated and new assignments are proposed based on comparison of the spectra and consideration of the polarisation of Raman lines.
Abstract: Infrared and Raman spectra of dimethylsulfoxide and dimethylsulfoxide- d 6 have been re-investigated. New assignments are proposed based on comparison of the spectra of various physical states and consideration of the polarisation of Raman lines. In the liquid state dimers and/or higher aggregates are present, but there is no evidence of autoassociation for concentrations less than 0,5 mole.l −1 . The autoassociation constants calculated by earlier authors are incorrect as they are based on erroneous assignments.
118 citations
TL;DR: In this article, the results of new measurements of the infrared spectra (3650-50 cm −1 ) together with the Raman shifts, wavenumbers for all the fundamental frequencies, and complete interpretations of the observed spectra are presented for the fifteen compounds p -XC 6 H 4 Y; X, Y = CH 3, F, Cl, Br or I.
Abstract: Utilising the results of new measurements of the infrared spectra (3650-50 cm −1 ) together with the Raman shifts, wavenumbers for all the fundamental frequencies, and complete interpretations of the observed spectra are presented for the fifteen compounds p -XC 6 H 4 Y; X, Y = CH 3 , F, Cl, Br or I.
111 citations
TL;DR: In this article, the infrared and Raman spectra for fifteen compounds, o-, m- or p-XC6H4NO2; X = CH3, F, Cl, Br, or I are presented and interpreted in detail.
Abstract: The infrared (3650–50 cm−1) and Raman spectra for the fifteen compounds, o-, m- or p-XC6H4NO2; X = CH3, F, Cl, Br, or I are presented and interpreted in detail, and the vibrations associated with the NO2 group are identified.
98 citations
TL;DR: In this article, the effects of ionisation on other organophosphorus correlations are discussed, as well as the effect of ionization on the properties of the corresponding IR bands assigned to PO2, PO32−, PO43−, POS−, PS2− and dialkyl phosphite anions.
Abstract: Correlations are presented for infrared absorption bands assigned to PO2−, PO32−, PO43−, POS−, PS2− and dialkyl phosphite anions, to zwitterions, and to phosphonium cations. The effects of ionisation on other organophosphorus correlations are also discussed.
78 citations
TL;DR: In this article, complete assignments and full interpretations of the infrared (3650-50 cm−1) and Raman spectra for the fifteen compounds m-XC6H4Y were proposed.
Abstract: Complete assignments, and full interpretations, of the infrared (3650-50 cm−1) and Raman spectra, are proposed for the fifteen compounds m-XC6H4Y; X, Y = CH3, F, Cl, Br or I.
70 citations
TL;DR: The vibrational spectrum of crystalline squaric acid (1,2-dihydroxycyclobutenedione) has been recorded at and below ambient temperature as discussed by the authors.
Abstract: The vibrational spectrum of crystalline squaric acid (1,2-dihydroxycyclobutenedione) has been recorded at and below ambient temperature. The infrared spectrum has been taken between 200 and 4000 cm−1, and the Raman spectrum has been taken between 85 and 2000 cm−1. Eighteen of the twenty infrared active vibrations and twenty of the twenty-four Raman active vibrations have been observed. Factor group splitting has been detected in both the infrared and Raman spectra. The spectrum of the deuterium compound has also been recorded. A correlation between the apparent degrees of association of several cyclobutenedione systems and their carbonyl stretching frequencies is given. The O⋯O distance in squaric acid (2.49 ± 0.05 A) has been estimated by a modification of the procedure given by Pimentel and McClellan. The results of our investigation indicate that squaric acid possesses an exceptionally strong hydrogen bond which is best described by a very asymmetric double minimum potential function.
66 citations
TL;DR: In this article, complete assignments and full interpretations of the infrared (3650−50 cm−1) and Raman spectra are proposed for the fifteen compounds o-C6H4Y; X, Y = CH3, F, Cl. Br or I.
Abstract: Complete assignments and full interpretations of the infrared (3650–50 cm−1) and Raman spectra are proposed for the fifteen compounds o-XC6H4Y; X, Y = CH3, F, Cl. Br or I.
63 citations
TL;DR: In this article, solvent effects on the visible absorption (charge transfer) spectra of bis-(2,2'-bipyridyl)biscyanoiron(II), bis-(1,10-phenanthroline), and ligand-substituted derivatives are correlated with solvent E T parameters.
Abstract: Solvent effects on the visible absorption (charge transfer) spectra of bis-(2,2'-bipyridyl)biscyanoiron(II), bis-(1,10-phenanthroline)biscyanoiron(II) and ligand-substituted derivatives are reported and correlated with solvent E T parameters.
63 citations
TL;DR: In this article, the infrared spectra of gaseous HCCl 3 and DCCl 3 were reported and the most likely force field was derived from the literature values of D j D jk, and isotopic splittings.
Abstract: The infrared spectra of gaseous HCCl 3 and DCCl 3 are reported Frequencies, 35 Cl/ 37 Cl isotope splittings, and ζ constants together with literature values of D j D jk , and isotopic splittings are combined to compute the most likely force field reproduced in Table 5
57 citations
TL;DR: In this article, the far infrared spectra (400-30 cm−1) of phthalocyanine and its metal derivatives were systematically studied and the assignments were proposed for the individual absorption bands observed.
Abstract: The far infrared spectra (400-30 cm−1) of phthalocyanine and its metal derivatives were systematically studied and the assignments were proposed for the individual absorption bands observed. Particular attention was paid to the absorption characteristics of each metal phthalocyanine as well as the metal-ligand vibrations. The electronic configuration of the central metal ion was discussed on the basis of these metal-dependent bands in which the zinc derivative showed a special aspect in the spectra.
TL;DR: In this article, the equilibrium constants of 1:1 and 2:1 stoichiometric complexes have been determined, which are related to the sum of the Hammett σ constants by the following relations: log K1 = 1.73 + 1.30Σσ log K2= 1.57 + 0.05 Σσ+ 0.94 (σ)2 Log K1 is linearly related to Δμ.
Abstract: Resume The complexes formed between triethylamine and phenols have been studied by infrared spectrometry in carbon tetrachloride solution at 30°C. The phenols have been chosen so that their pKα vary from 10·30 to 3·50. The apparent complexation constant, calculated on the model of a 1:1 stoichiometric complex shows a marked variation with the concentration in free proton donor. Using a method based on the variation of this “apparent constant”, the equilibrium constants of 1:1 (K1) and 2:1 (K2) stoichiometric complexes have been determined. These values are related to the sum of the Hammett σ constants (Σσ) by the following relations: log K1 = 1.73 + 1.30Σσ log K2= 1.57 + 0.05 Σσ + 0.94 (Σσ)2 Log K1 is linearly related to Δμ, the increment of dipole moment, determined by Ratajcyak and Sobczyk, in benzenic solution. On the other hand, equation (2) is compared to an expression, obtained previously in the study of the complexation of substituted phenols-substituted anilines, showing that the logarithm of the complexation constant depends on an interaction term depending on the product of the substitution constants σaσb. The formation of a complex of 2:1 stoichiometry gives a characteristic vibration band lying at some 100 cm−1 lower than the dimeric phenol; this constatation is explained in terms of the greater basicity of the oxygen atom in the 1:1 complex than in the dimeric phenol. The CH stretching vibrations of the triethylamine are disturbed in frequency and intensity by the formation of a hydrogen bond; this perturbation increases with the phenol acidity.
TL;DR: In this article, the infrared spectrum of some LiX III O 2 compounds with an ordered distribution of Li and X III cations on octahedral sites has been investigated with the help of 6 Li-7 Li isotopic replacement.
Abstract: The infrared spectrum of some LiX III O 2 compounds (X III = Al, Ga, Co, Cr, Rh, Sc) with an ordered distribution of Li and X III cations on octahedral sites has been investigated with the help of 6 Li- 7 Li isotopic replacement The spectrum is essentially characterized by the occurrence of distinct, well individualized, X III O 6 (in the 650–400 cm −1 region) and LiO 6 (in the 300–200 cm −1 region) frequencies However, this vibrational behaviour seems to be restricted to the compounds with the rhombohedral R 3 m structure and cannot be generalized to all LiXO 2 compounds Some specific features of the individual spectra have also been discussed
TL;DR: In this article, the spectra of 22 compounds were studied in the region 2000 −40 cm −1, and the differences between XO 4 tetrahedra and XO 6 octahedra were established.
Abstract: The spectra of 22 compounds were studied in the region 2000–40 cm −1 . The spectra of the 13 compounds with the scheelite structure were interpreted according to the site group and factor group approximations. The differences between the spectra of compounds containing XO 4 tetrahedra and XO 6 octahedra were established.
TL;DR: In this paper, it has been proved that for almost all electro-optical parameters, it is possible to determine values which are commonly applicable to all chlorinated methane molecules, but for μ CH and ∂μ CH / ∂ r CH, it is not possible to find commonly applicable values.
Abstract: Infrared band intensities of three molecular species CHCl 3 , CDCl 3 and CCl 4 , were measured in the vapour phase and the band intensity data of thirteen kinds of various chlorinated methanes, from methane to carbon tetrachloride, have been interpreted by means of as few as possible common intensity parameters. The parameters have been determined by using the least squares method from the observed data on the basis of the valence-optical theory. As a result, it has been proved that for almost all electro-optical parameters, it is possible to determine values which are commonly applicable to all chlorinated methane molecules, but for μ CH and ∂μ CH / ∂ r CH , it is not possible to find commonly applicable values.
TL;DR: The infra-red spectra of 78 double salts of which 64 are Tutton's salts have been investigated in the region 2000-40 cm−1, and are considered in terms of the site group and factor group approximations.
Abstract: The infra-red spectra of 78 double salts of which 64 are Tutton's salts have been investigated in the region 2000–40 cm−1, and are considered in terms of the site group and factor group approximations The magnitude of the deviations from the free-ion selection rules is not related to any structural parameter
TL;DR: In this paper, a normal co-ordinate analysis has been made using a valence force field with some constraints, which suggests an increasing SiSi stretching force constant in the series (Si 2 H 6 2 I 6 2 Br 6 2 Cl 6 ) caused by second order hybridization and by interaction of silicon d -orbitals.
Abstract: Infrared and Raman spectra of Si 2 Cl 6 , Si 2 Br 6 , and Si 2 I 6 have been measured. A normal co-ordinate analysis has been made using a valence force field with some constraints. It suggests an increasing SiSi stretching force constant in the series (Si 2 H 6 2 I 6 2 Br 6 2 Cl 6 caused by second order hybridization and by interaction of silicon d -orbitals.
TL;DR: In this paper, the authors compared the sensitivities of these charge-transfer bands to solvent variation for these systems and for Fe(LL) 2 (CN) 2, where LL = bipy, ophen, or one of their substituted derivatives, and M(bipy)(CO) 4, where M = Mo or W.
Abstract: Wavelengths of maximum absorption for charge-transfer spectra of Fe(LL) 2 (CN) 2 , where LL = bidentate Schiff base, Fe(bipy)(CN) 4 2− , and Fe(ophen) 2 (CN) 2 + in a range of solvents are reported. The frequencies correlate with Reichardt's solvent parameter E T . The sensitivities of these charge-transfer bands to solvent variation are compared for these systems and for Fe(LL) 2 (CN) 2 , where LL = bipy, ophen, or one of their substituted derivatives, and M(bipy)(CO) 4 , where M = Mo or W.
TL;DR: In this paper, the infrared spectra of 2-chloro, 2-bromo and 2-iodo were recorded in the gaseous and liquid states in the region 5000-200 cm −1.
Abstract: The infrared spectra of 2-chloro, 2-bromo, 2-iodo and 2-cyanopropane (the isopropyl halides and isopropyl cyanide) were recorded in the gaseous and liquid states in the region 5000–200 cm −1 . Raman spectra of the liquids were obtained using He-Ne laser excitation and semiquantitative polarization data are reported. The vibrational spectra of these substances are very closely related and the spectra are interpreted in terms of C s , symmetry for all the molecules. A tentative assignment of the fundamental frequencies for each compound is proposed.
TL;DR: In this paper, the vibration frequencies of structures which typify ortho silicate, pyro silicates, chain and sheet have been calculated using an extension of the Wilson GF method, in order to confirm the general interpretation of Raman spectra of binary glasses.
Abstract: The vibration frequencies of structures which typify ortho silicate, pyro silicate, chain and sheet have been calculated using an extension of the Wilson GF method, in order to confirm the general interpretation of Raman spectra of binary glasses.
TL;DR: In this article, the infrared and Raman spectra between 3000 and 500 cm −1 have been assigned for eight isotopic species of methyl ethyl ether and two conformers are observed at room temperature; the more stable conformer, trans, is the only one left at 80°K.
Abstract: Infrared and Raman spectra between 3000 and 500 cm −1 have been partly assigned for eight isotopic species of methyl ethyl ether. Two conformers are observed at room temperature; the more stable conformer, trans , is the only one left at 80°K. The energy difference found between the two forms is about 1–35 kcal mole .
TL;DR: In this article, the spectra of twenty 2-substituted thiophenes, SC 4 H 3 X, were analyzed over the range 200-1700 cm −1 and around 3000 cm − 1.
Abstract: The spectra of twenty 2-substituted thiophenes, SC 4 H 3 X, were analysed over the range 200–1700 cm −1 and around 3000 cm −1 . An assignment of the fundamental vibrations of thiophenic ring in these compounds is proposed; three series of frequencies are interpreted as resulting of important coupling between νC—X vibration and two thiophenic skeletal vibrations, Some assignments for substituents are discussed.
TL;DR: In this article, the spectral lines are remarkably sharp and intense, and depend more on the nature of the M''' than on the M' cations, while the infrared spectra of 18 Tutton salts are more sensitive to the nature M'' cation than to the m' cation.
Abstract: Infrared spectra of 22 alums (including α, β and γ types) show simple v 3 and v 4 sulfate vibrational peaks indicating essentially T d symmetry, plus numerous peaks due to water coordinated about the M''' and M' ions. There are few simple correlations of spectra with change in either cation, but the position of v 3 is slightly affected by change from α to β structure. Infrared spectra of 18 Tutton salts are more sensitive to the nature of the M' cation than to the M'' cation. The effective SO 4 symmetry is C 3 v . Infrared spectra of 24 dehydrated alums fall into two main symmetry patterns for SO 4 , C 3 v , for Al''' and C 2 v , (probably) for other M''' ions. The spectral lines are remarkably sharp and intense, and depend more on the nature of the M''' than on the M' cations. The rock and wag frequencies for waters “octahedrally” coordinated to M''', M'', and M' cations can be systemized in terms of ionic charge and presence or absence of d orbitals in the cation.
TL;DR: In this paper, the far-infrared and Raman spectra of biopolymers such as DNA, RNA and synthetic polynucleotides were determined in the crystalline state.
Abstract: As a partial basis for future interpretation of the far-infrared and Raman spectra of biopolymers such as DNA, RNA and synthetic polynucleotides, the low-frequency infrared and Raman spectra, 30–230 cm−1, of 1-methyluracil, 1-methylthymine, 9-methyladenine and the 1:1 complex of the last two were determined in the crystalline state. The spectra were interpreted with the help of a normal-coordinate treatment based on two highly simplified models, one in which all intermolecular forces were neglected except those of hydrogen bonding and the other in which van der Waals forces between hydrogen atoms were also included. The latter model gave better results at the expense of introduction of an additional parameter. The hydrogen-bond stretching frequencies for these crystals lie in the range 125–70 cm−1 and show up only feebly in the Raman effect, whereas the out-of-plane molecular librations are quite intense. These librations and the translational lattice modes have frequencies below 100 cm−1. In addition to these lattice modes, intramolecular out-of-plane ring-deformation vibrations also appear in the far-infrared spectra in the range 220–135 cm−1.
TL;DR: In this article, the low-frequency infrared and Raman spectra of some pseudo tetrahedral complexes of the formula ZnL 2 X 2 (L = NH 3, ND 3, imidazole, imidaze- d 4, and 1-methyl-imidazoles; X = Cl, Br, I) are reported.
Abstract: The low-frequency (500–40 cm −1 ) infrared and Raman spectra of some pseudo tetrahedral complexes of the formula ZnL 2 X 2 (L = NH 3 , ND 3 , imidazole, imidazole- d 4 , and 1-methyl-imidazole; X = Cl, Br, I) are reported. The vibrations of Zn(NH 3 ) 2 Cl 2 , crystals have been classified using factor and site group analyses; seven of the nine metal-ligand vibrations have been assigned. The assignment of the metal-ligand vibrations of imidazole complexes is more complicated since some of these modes appear to be mixed, particularly with rotational vibrations of the nitrogen ligand which is not the case in ammonia complexes. Approximate Zn-N and Zn-X stretching force constants have been calculated.
TL;DR: In this article, the complete vibrational spectra of sila cyclo butane, (CH 2 ) 3 SiH 2, and of three of its derivatives, where X = D, F, Cl, have been recorded and an assignment for each molecule is proposed.
Abstract: The complete vibrational spectra of sila cyclo butane, (CH 2 ) 3 SiH 2 , and of three of its derivatives, (CH 2 ) 3 SiX 3 where X = D, F, Cl, have been recorded and an assignment for each molecule is proposed. A normal-coordinate calculation for each of these molecules was carried out to test the assignment and to demonstrate coupling between various vibrational modes. Considerable mixing of the modes was found. An analysis of the spectra shows that all four of these four-membered ring compounds are non-planar and have C 3 symmetry.
TL;DR: In this article, the infrared and Raman spectra of the pyrimidine complexes Hg(C 4 H 4 N 2 )X 2 (X = Cl, Br) and several pyrimidinium salts have been obtained in the 3200-300 cm −1 range.
Abstract: The infrared and Raman spectra of the pyrimidine complexes Hg(C 4 H 4 N 2 )X 2 (X = Cl, Br) and of several pyrimidinium salts have been obtained in the 3200-300 cm −1 range. An aqueous solution of pyrimidinium chloride has also been studied by Raman spectroscopy. An assignment of the observed bands is proposed. Frequency shifts of pyrimidine due to co-ordination with metal and to protonation are discussed.
TL;DR: In this paper, the infrared and Raman spectra of single crystal samples of naphthalene-d 8 have been recorded over the entire energy range of the fundamental vibrations and the spectra in all independent polarizations are presented.
Abstract: Infrared and Raman spectra of single crystal samples of naphthalene- d 8 have been recorded over the entire energy range of the fundamental vibrations. The spectra in all independent polarizations are presented. Depolarization ratios for the Raman lines in carbon tetrachloride and benzene solutions are reported. These data have been used to make a firm assignment of the molecular fundamentals; however, this experimental assignment remains incomplete. Where possible, comparisons have been made with the results of recent force-field calculations and the agreement is generally very good.
TL;DR: In this paper, the infrared and Raman spectra of trimethylamme oxide, trimethylphosphine oxide, and trimethylaraine oxide are reported and discussed.
Abstract: The infrared and Raman spectra of trimethylamme oxide, trimethylphosphine oxide, and trimethylaraine oxide are reported and discussed. The normal co-ordinate treatment by Wilson's matrix method has permitted assignment of the frequencies, calculation of the force constants, and the choice of a force field which satisfactorily describes each molecule. The bond orders calculated by Gordy's and Siebert's formulae, have been found to account for the nature of NO, PO and AsO bonds in these compounds. An interpretation based on overlapping of p π d π orbitals has been proposed.
TL;DR: In this paper, the infrared and Roman spectra of trimethylsilyl compounds (CH3)3SiElVH2 (ElV = P, As), (CH 3Si3SiPD2, [(CH 3]3Si]2ELVH, As, Sb, and Sb) were reported.
Abstract: The infrared (4000-50 cm−1) and Roman spectra of the trimethylsilyl compounds (CH3)3SiElVH2 (ElV = P, As), (CH3)3SiPD2, [(CH3)3Si]2ElVH (EiV = P, As), [(CH3)3Si]2PD, and [(CH3)3Si]3ElV (ElV = N, P, As, and Sb) are reported. An assignment is given on the basis of force constant calculations for (H3Si)3ElV and [(CH3)3Si]3ElV molecules where ElV = N, P, As, and Sb. If reasonable values for the SiBlV/Si'ElV interaction force constants are assumed, the SiElVSi bond angles are restricted to ≅120° (ElV = N) and 90–100° (ElV = P, As, and Sb). The SiElV stretching force constants are listed in Table 9.