Hydrogen bonding by hydroxylic solvents to aromatic amines. Effects on spectra and relative basicities of some N-(4-nitrophenyl)polymethylenimines

Kamlet, Mortimer J.; Minesinger, Richard R.; Kayser, Eleonore G.; Aldridge, Mary H.; Eastes, John W.

doi:10.1021/jo00824a002

Cited by 25 publications

(11 citation statements)

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“…As before, it is seen that the results satisfy the initial requirement for documentation of hydrogen-bonding effects by the solvatochromic comparison method in that the The further condition is also fulfilled that vmax values in the HBD solvents (triangles) deviate from the regression equation by statistically significant amounts. Displacements attributable to hydrogen bonding, calculated from the equation -AAv(3-1)a-o=c = "(3)eq 4(calcd) -"(3)max(obsd) (5) are included in Table 1 and, for the R-OH solvents, are all greater than 3.6 times the standard deviation for the non-HBD solvents.16•17…”

Section: Acidities4mentioning

confidence: 99%

“…Burgess' Fe(LL)2(CN)2 Spectra. Burgess22 has described medium effects on the metal to ligand charge-transfer bands in the uv-visible spectra of a number of metal clathrate complexes including bis[a-(2-pyridylbenzylidene)-3,4-dimethylaniline]bis(cyano)iron(II), Fe(LL)2(CN)2 (5). Solvent absorption obscures the spectrum of 1 in several of the solvents employed in Burgess' study, so solvatochromic comparison in this instance is between 5 and an alternative reference substrate, MN-diethyM-nitroaniline (6).…”

Section: Acidities4mentioning

confidence: 99%

“…Although we are not now able to pinpoint where Fe(LL)2(CN)2 association with the HBD solvents takes place, there seems no question that we are dealing with type-A hydrogen-bonding phenomena. 5 The comparison of AAv(5-6)a values with corresponding //(2-1) ^-results is shown in Figure 6. Linear correlation in this instance is fair; the regression equation is //(5-6) = 0.210[ /'(2-1) _^-_ ] + 0.14 kK ( 12) with = 10, r = 0.934, and SD = 0.13 kK.24…”

Section: Acidities4mentioning

confidence: 99%

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The solvatochromic comparison method. 2. The .alpha.-scale of solvent hydrogen-bond donor (HBD) acidities

Taft¹,

Kamlet²

1976

J. Am. Chem. Soc.

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1,254

661

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28869.5 ml(20-50-fold excess) of alcohol solution and thermostating for the period of time required for the disappearance of the yellow color of Cr(V1). Sodium hydroxide (100 ml, 2.5 M) was then added with cooling to the mixture to neutralize the acetic acid. Completeness of neutralization was monitored with pH paper. The resulting aqueous solution was twice extracted with 100 ml of ether, and the combined ether extracts were washed with water and dried (MgS04) and evaporated to a volume of ca. 0.5 ml. The mixture was then analyzed on a Hewlett-Packard Model 700 gas chromatograph equipped with dual flame ionization detectors. In each case, only the alcohol starting material and normal oxidation product were detected.Determination of Activation Parameters. Once the rate constants at various temperatures had been determined, Arrhenius plots of the natural logarithm of the rate constant against the reciprocal of the absolute temperature were made. To aid in the accurate plotting of these data and their linear regression analysis, the University of Delaware Burroughs B-6700 computer was utilized. The appropriate program was written by Dr. John J. Stanulonis of these laboratories and made available to us. The program permitted the determination of the least-squares slope of the plot and its intercept, as well as statistical information which indicated the reliability of the data. The statistical equations were those suggested by B a~e r .~~ From the slope of the Arrhenius plot, the energy of activation may be determined, using the relationshipPlotting In k vs. Am. Chem. Soc., 95,5242 (1973).A most recent review is given in H. Taube, A&. "rg. Chem. Radiochem., 1, l(1959).See R. P. Bell. Chem. Soc. Rev., 3,513 (1974). for a recent general review of this subject: see also, J. R. Hulett, 0. Rev., Chem. Abstract: The solvatochromic comparison method is used to evaluate hydrogen-bonding contributions in HBD (hydrogen-bond donor) solvents to several commonly used dye indicator solvent polarity scales (Dimroth's E~o , Brooker's XR. Kosower's Z ) . Hydrogen-bonding effects on other spectral properties, equilibria, and reaction rates are determined, and the results are used to construct an a-scale of solvent HBD acidities.X Y Z = X Y Z o + solvent polarity-polarizability effect Journal of the American Chemical Society / 98:lO / M a y 12, 1976

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Section: Acidities4mentioning

confidence: 99%

Section: Acidities4mentioning

confidence: 99%

Section: Acidities4mentioning

confidence: 99%

See 1 more Smart Citation

The solvatochromic comparison method. 2. The .alpha.-scale of solvent hydrogen-bond donor (HBD) acidities

Taft¹,

Kamlet²

1976

J. Am. Chem. Soc.

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1,254

661

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“…In this paper, we will present studies on the Raman spectrum of N , N -dimethyl- p -nitroaniline (DMPNA) (see Scheme ) and the excitation wavelength dependence of the Raman Stokes shift of the NO 2 stretching mode in various kinds of RTILs. DMPNA is also a typical solvatochromic molecule, and Kamlet−Taft solvatochromic parameters have been determined by the absorption spectra of related compounds such as p -nitroaniline (PNA), N , N -diethyl- p -nitroaniline (DEPNA), and p -nitroanisole. − The electronic states of DMPNA are also approximately described by the superposition of the resonant forms like PB (see Scheme ). Due to this nature of the charge transfer transition between the ground and excited states, the absorption peak of DMPNA is occasionally used to estimate the π* value in the replacement of p -nitroanisole .…”

Section: Introductionmentioning

confidence: 99%

Raman Spectroscopic Study on the Solvation of N,N-Dimethyl-p-nitroaniline in Room-Temperature Ionic Liquids

2007

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Electronic absorption spectra and Raman spectra of N,N-dimethyl-p-nitroaniline (DMPNA) have been measured in various fluids from the gaseous-like conditions in supercritical fluids (SCFs) to highly polar room-temperature ionic liquids (RTILs). We found that the S0-S1 absorption band center of DMPNA in RTILs is mostly determined by the molar concentrations of ions. On the other hand, the bandwidth of the absorption spectrum does not follow the expectation from a simple dielectric continuum model. Especially in SCFs, the bandwidth of the absorption spectrum decreases with increasing solvent density, suggesting that the intramolecular reorganization energy is a decreasing function of the solvent density. The Raman shift of the NO2 stretching mode has been proven to be a good indicator of the solvent polarity; i.e., the vibrational frequency of the NO2 stretching mode changes from 1340 cm-1 in mostly nonpolar solvent such as ethane to 1300 cm-1 in water. The linear relationship between the absorption band center and the vibrational frequency of the NO2 mode, which was observed for conventional liquids in a previous paper (Fujisawa, T.; Terazima, M.; Kimura, Y. J. Chem. Phys. 2006, 124, 184503), holds almost well for all fluids including SCFs and RTILs. On the other hand, the vibrational bandwidth does not show a simple relationship with the absorption band center. The vibrational bandwidths in RTILs are generally larger in comparison with those in conventional liquids with similar polarity scales. Among the RTILs we investigated, the vibrational bandwidth loosely correlates with the molecular size of the anion. A similar dependence on the anion size is also observed for the bandwidth of the absorption spectrum. We have also investigated the excitation wavelength dependence of the Raman shift of the NO2 stretching mode in RTILs. The extent of the dependence on the excitation wavelength in all fluids is well correlated with the vibrational bandwidth.

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“…), 1.408 (7); C(2)-C(3), 1.414 (6);C(3)-C(4), 1.403 (7); P-C(l), 1.758 (5); P-C(4), 1.768 (5);C(2)-C(5), 1.503 (8); C(3)-C( 6), 1.516 (8); C(7)-C(8), 1.378 (12); C(8)-C(9), 1.411 (9);C(9)-C(10), 1.412 (10); C(10)-C(l 1), 1.393 (10); C(11 )-C(7), 1.399 (10); Fe-P, 2.276 (1): -C(l), 2.064 (4); -C(2), 2.046 (4); -C(3), 2.040 (4); -C(4), 2.051 (4); -C(7), 2.046 (6); -C(8), 2.036 (7); -C(9), 2.027 (6); -C(10), 2.039 (5); -C(l 1), 2.045 (4).…”

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The dependence of phenol-dienone tautomerism upon the hydrogen bonding characteristics of the solvent: 3,5-dipyrrolidinophenol

Highet¹,

Chou²

1977

J. Am. Chem. Soc.

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Hydrogen bonding by hydroxylic solvents to aromatic amines. Effects on spectra and relative basicities of some N-(4-nitrophenyl)polymethylenimines

Cited by 25 publications

References 0 publications

The solvatochromic comparison method. 2. The .alpha.-scale of solvent hydrogen-bond donor (HBD) acidities

The solvatochromic comparison method. 2. The .alpha.-scale of solvent hydrogen-bond donor (HBD) acidities

Raman Spectroscopic Study on the Solvation of N,N-Dimethyl-p-nitroaniline in Room-Temperature Ionic Liquids

The dependence of phenol-dienone tautomerism upon the hydrogen bonding characteristics of the solvent: 3,5-dipyrrolidinophenol

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