n-π Electron donor–acceptor complexes. III. Aliphatic amines with dicyanobenzenes. Electric and steric effects of the N-substituents on complex formation

1986 ◽  
Vol 64 (8) ◽  
pp. 1491-1495 ◽  
Author(s):  
Jorge D. Anunziata ◽  
Norma S. Galaverna ◽  
Joaquín O. Singh ◽  
Juana J. Silber
Keyword(s):  
Electron Donor ◽  
Aliphatic Amines ◽  
Steric Effects ◽  
Probable Structure ◽  
Spectroscopic Behaviour ◽  
Amine Structure ◽  
Donor Acceptor ◽  
Substituent Constants ◽  
The Stability ◽  
Electronic And Steric Effects

The interaction of several aliphatic amines as n-donors with 1,2-, 1,3-, and 1,4-dicyanobenzenes as π acceptors in n-hexane has been studied. The spectroscopic behaviour of the mixtures leads us to propose that Electron Donor – Acceptor (EDA) complexes are formed. Correlations of the experimental data with the amine structure were performed for the amine–1,4-dicyanobenzene complexes. By means of free energy related substituents and regression analysis, the electronic and steric effects of three N-substituents were quantitatively separated. Thus, with K representing the stability constants of the complexes, the values of log K are correlated with Taft's polar substituent constants, σ*, and Hancock's corrected steric substituent constants, [Formula: see text] The results allowed the proposal of a probable structure of the complex, at least with respect to the donor orientation.

n–π Electron donor–acceptor complexes. II. Aliphatic amines with dinitrobenzenes

1985 ◽  
Vol 63 (4) ◽  
pp. 903-907 ◽  
Author(s):  
Joaquín O. Singh ◽  
Jorge D. Anunziata ◽  
Juana J. Silber
Keyword(s):  
Electron Donor ◽  
Iterative Procedure ◽  
Steric Effect ◽  
Aliphatic Amines ◽  
Primary Amines ◽  
Substitution Reactions ◽  
Aromatic Nucleophilic Substitution ◽  
Donor Acceptor ◽  
Eda Complex ◽  
The Stability

The interaction of several aliphatic amines as n-donors and dinitrobenzenes (DNB) as π-acceptors has been studied in n-hexane. The formation of electron donor – acceptor (EDA) complexes is proposed to explain the spectroscopic behaviour of the mixtures. The stability constants (Ks) for these complexes have been calculated by an iterative procedure. For a given acceptor, the donor strength of RNH2 > R2NH > R3N was found. This order is explained by considering the role that steric effect may play in the EDA complex formation. On the other hand, the fact that for a given donor Ks follows the order 1,2-DNB > 1,3-DNB > 1,4-DNB, and that 1,2-DNB reacts with primary amines, led to the proposal of orientational complexes. These EDA complexes may be considered intermediates in aromatic nucleophilic substitution reactions.

Interaction between tetracyanoethylene and naphthalene in reverse micelles of AOT in n-hexane. The electron-donor properties of AOT

1996 ◽  
Vol 74 (9) ◽  
pp. 1603-1608 ◽  
Author(s):  
M. A. Biasutti ◽  
Juana J. Silber
Keyword(s):  
Electron Donor ◽  
Reverse Micelles ◽  
Formation Constants ◽  
Local Concentration ◽  
Micellar Media ◽  
Visible Spectroscopy ◽  
Donor Acceptor ◽  
Uv Visible ◽  
The Stability ◽  
Homogeneous Media

The electron donor–acceptor (EDA) interaction between TCNE and naphthalene (Naph) in n-hexane and reverse micelles of AOT in n-hexane was studied by UV–visible spectroscopy with the aim of determining the influence of the micellar media on the EDA interaction. The spectra of the mixtures of TCNE–Naph in n-hexane show two typical maxima at 418 and 534 nm, assigned to the formation of a π–π EDA complex. In the micellar media a new band is observed at 398 nm. When the spectra of TCNE in n-hexane are studied in the presence of AOT two new bands at 398 and 418 nm are detected. These bands are consistent with an EDA interaction between TCNE and AOT as n-donor. The stability constants of this interaction were calculated for AOT concentrations below the CMC and in the micellar media at different W(W = [H2O]/[AOT]). The results give evidence of the tendency of AOT to interact very strongly with electron acceptors. Moreover, in the system TCNE–Naph in the micellar media it is shown that Naph and AOT compete to form a complex with TCNE. The formation constants of the complexes of AOT–Naph in the micelle system were determined at W = 0 and 5. Despite the competition of AOT for TCNE the stability constant for the complex TCNE–Naph is higher than in homogeneous media, probably due to the high local concentration of the acceptor in the micelle. Key words: reverse micelles, aerosol-OT, tetracyanoethylene, naphthalene, electron donor–acceptor complexes.

n–π Electron donor–acceptor complexes. I. Aliphatic amines with benzonitrile

1981 ◽  
Vol 59 (9) ◽  
pp. 1291-1296 ◽  
Author(s):  
J. Anunziata ◽  
J. Singh ◽  
J. J. Silber
Keyword(s):  
Experimental Data ◽  
Temperature Effect ◽  
Electron Donor ◽  
Iterative Procedure ◽  
Extinction Coefficients ◽  
A Value ◽  
Amine Structure ◽  
Donor Acceptor ◽  
Spectroscopic Behavior ◽  
Weak Electron

Interaction of diethyl, triethyl, n-butyl, di-n-butyl and tri-n-butyl amines as n-donor with benzonitrile as π-acceptor has been studied in n-hexane. The formation of weak electron donor–acceptor (EDA) complexes is proposed to explain the spectroscopic behavior of the mixtures. An iterative procedure was used to obtain values of stability constants (K) and extinction coefficients (ε). The fact that from the new absorption observed for these systems a value of K and a finite constant value of ε could be determined gives proof of the existence of EDA complexes. This conclusion is further supported by the temperature effect observed. Correlations of the experimental data with amine structure and other types of amine complexes were found.

scholarly journals Deaminative Borylation of Aliphatic Amines Enabled by Visible Light Excitation of an Electron Donor-Acceptor Complex

2018 ◽  
Vol 24 (65) ◽  
pp. 17210-17214 ◽  
Author(s):  
Frederik Sandfort ◽  
Felix Strieth-Kalthoff ◽  
Felix J. R. Klauck ◽  
Michael J. James ◽  
Frank Glorius
Keyword(s):  
Visible Light ◽  
Electron Donor ◽  
Aliphatic Amines ◽  
Acceptor Complex ◽  
Donor Acceptor ◽  
Light Excitation
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