Reversible dimerization of the benzonitrile radical-anion

Conclusions Cyclic voltamperometric data indicated that the benzonitrile anion-radical undergoes reversible dimerization in DMF containing tetraethylammonium perchlorate.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2170–2171, September, 1988.     

Kinetics of the formation of benzoguanamine from dicyandiamide and benzonitrile

The rates of the formation of benzoguanamine from dicyandiamide and benzonitrile in the presence of a basic catalyst, have been measured by means of UV spectrophotometry. The rate is expressed as ν = k × [dicyandiamide]·[benzonitrile]·[KOH]. Since the addition of a small amount of cyanamide retards the rate, cyanamide cannot be an intermediate. Application of the rate data observed with p-methyl-, methoxy-, and chlorobenzonitriles to the Hammett's equation gives a positive value of +1·82. A probable mechanism involving a rate-determining attack of the conjugate base of dicyandiamide on benzonitrile is suggested and discussed.     

Self-directed growth of benzonitrile line on H-terminated Si(001) surface

Using first-principles density-functional calculations we predict a self-directed growth of benzonitrile molecular line on a H-terminated Si(001) surface. The C[triple bond]N bond of benzonitrile reacts with a single Si dangling bond which can be generated by the removal of a H atom, forming one Si-N bond and one C radical. Subsequently, the produced C radical can be stabilized by abstracting a H atom from a neighboring Si dimer, creating another H-empty site. This H-abstraction process whose activation barrier is 0.65 eV sets off a chain reaction to grow one-dimensional benzonitrile line along the Si dimer row. Our calculated energy profile for formation of the benzonitrile line shows its relatively easier formation compared with previously reported styrene and vinylferrocene lines.     

1,3-dipolar cycloaddition of benzonitrile oxide with vinylsilanes

The reaction of benzonitrile oxide with several vinylsilanes has been found to afford silylated isoxazoles. Relative rates for the cycloaddition reaction were determined.     

Molecular recognition in the gas phase. Dipole-bound complexes of benzonitrile with water, ammonia, methanol, acetonitrile, and benzonitrile itself

Described herein are the high resolution fluorescence excitation spectra of 1 : 1 complexes of benzonitrile with water, ammonia, methanol, acetonitrile, and benzonitrile itself in the gas phase. Analyses of these spectra yield the equilibrium geometries of each species in both the ground and excited electronic states, and therefore provide information about the intermolecular interactions that are responsible for holding them together, in the absence of perturbing solvent molecules. In all cases, the determined structure corresponds to the one expected on the basis of interacting dipole moments; in some cases, significant internal motions of one component relative to the other, leading to a time-varying dipole field, also has been observed.     

Additive-free vapour-phase hydrogenation of benzonitrile over MgO-supported Ni catalysts

Research on Chemical Intermediates - MgO-supported Ni catalysts were selectively catalysed by the hydrogenation of benzonitrile to benzylamine in continuous flow at atmospheric pressure without any...     

Regioselective additions of grignard and lithium reagents to 2-[(benzylidene)aminoi]benzonitrile and 2-[(diphenylmethylene)amino]benzonitrile

Phenylmagnesium bromide and methylmagnesium bromide in tetrahydrofuran undergo a regioselective addition to the cyano group of the two title compounds. Phenyllithium and methyllithium add selectively to the azomethine portion of 2-[(benzylidene)amino]benzonitrile, but to the cyano group of 2-[(diphenylmethylene)amino]benzonitrile. These addition reactions are utilized in the synthesis of quinazoline derivatives.     

Cycloaddition of benzonitrile oxide with some butadienylamines

A convenient and easy approach to the 4,5′-diisoxazole ring system, based on the cycloaddition of benzonitrile oxide to butadienylamines is deicribed. Both mono- and bis-adducts are obtained, whose structures have been confirmed by spectral analysis and chemical transformations. Addition on the base substituted double bond occurs with inversion of the orientation with regard to butadiene.     

Photoinduced Rydberg ionization spectroscopy of the B state of benzonitrile cation

Photoinduced Rydberg ionization (PIRI) spectra of the second excited electronic state of benzonitrile cation were recorded via the origin and 6a1 and 6b1 vibrational levels of the cation ground electronic state. This B<--X transition was verified to be a forbidden 2B2<--2B1 transition with an origin at 17,225 cm-1 above the ground ionic state. By the use of vibronic coupling calculations, as well as symmetry analysis and comparison of the PIRI spectra via different ground vibrational levels, a nearly complete assignment of the vibrational structure was made, and the vibrational frequencies of the B 2B2 state of benzonitrile cation were obtained based on the assignments. Comparisons of the experimental spectra with simulations from the vibronic structure calculations are also used to validate the theoretical procedures used in the simulations.     

The meta photocycloaddition of anisole and benzonitrile to 1,3-dioxol-2-one

The meta photocycloadditions of benzonitrile and anisole to 1,3-dioxol-2-one both yield two major products. In both cases the adducts are those which would be expected if some form of polar species were to develop along the reaction pathway. The absence of exo adducts in the case of benzonitrile and 1,3-dioxol-2-one is discussed.     

Reactions of benzonitrile oxide with fluoroketones and their imines

Conclusions Fluoroketones (I) and their imines (III) enter into a noncatalyzed addition reaction with benzonitrile oxide.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1916–1918, August, 1968.     

Ultrafast intramolecular charge transfer with strongly twisted aminobenzonitriles: 4-(di-tert-butylamino)benzonitrile and 3-(di-tert-butylamino)benzonitrile

The newly synthesized aminobenzonitriles with two bulky amino substituents 4-(di-tert-butylamino)benzonitrile (DTABN) and 3-(di-tert-butylamino)benzonitrile (mDTABN) have strongly twisted amino groups in the ground state. From X-ray crystal analysis it is found that the amino twist angle theta of mDTABN equals 86.5 degrees , whereas a twist angle of around 75 degrees is deduced for DTABN from the extinction coefficient of its lowest-energy absorption band in n-hexane. Because of the electronic decoupling between the amino and benzonitrile groups caused by these large twist angles, the absorption of DTABN and mDTABN is relatively weak below 40000 cm-1, with extinction coefficients around 25 times smaller than those of the planar 4-(dimethylamino)benzonitrile (DMABN). DTABN as well as mDTABN undergo efficient intramolecular charge transfer (ICT) in the singlet excited state, in nonpolar (n-hexane) as well as in polar (acetonitrile) solvents. Their fluorescence spectra consist of an ICT emission band, without evidence for locally excited (LE) fluorescence. The occurrence of efficient ICT with mDTABN is different from the findings with all other N,N-dialkylaminobenzonitriles in the literature, for which ICT only appears with the para-derivative. From solvatochromic measurements, an ICT dipole moment of 17 D is determined for DTABN as well as for mDTABN, similar to that of DMABN. The picosecond fluorescence decays of DTABN (time resolution 3 ps) are effectively single exponential. Their decay time is equal to the ICT lifetime tau'0(ICT), which increases with solvent polarity from 0.86 ns in n-hexane to 3.48 ns in MeCN at 25 degrees C. The femtosecond excited-state absorption (ESA) spectra of DTABN in n-hexane and MeCN at 22 degrees C show a decay of the LE and a corresponding rise of the ICT absorption. The ICT reaction time is 70 fs in n-hexane and 60 fs in MeCN. DTABN and mDTABN may have a strongly twisted ICT state, similar to that of 6-cyanobenzoquinuclidine but different from that of DMABN.     

Infrared vibrational autodetachment spectroscopy of microsolvated benzonitrile radical anions

Vibrational spectra of microsolvated benzonitrile radical anions (C6H5CN- -S; S = H2O and CH3OH) were measured by probing the electron detachment efficiency in the 3 microm region, representing resonance bands of autodetachment via OH stretching vibrations of the solvent molecules. The hydrogen-bonded OH band for both the cluster anions exhibited a large shift to the lower energy side with approximately 300 cm-1 compared to those for the corresponding neutral clusters. The solvent molecules are bound collinearly to the edge of the CN group of the benzonitrile anion in the cluster structures optimized with the density functional theory, in which the simulated vibrational energies are in good agreement with the observed band positions. Natural population analyses were performed for a qualitative implication in changes of solvent orientation upon electron attachment. Asymmetric band shapes depending on the vibrational modes are discussed with respect to dynamics of the autodetachment process from a theoretical aspect incorporated with density functional calculations.     

Diastereoselective cycloadditions of chiral homoallylic alcohols with benzonitrile oxide

The first diastereoselective cycloaddition of a nitrile oxide with a homoallylic alcohol is discussed. The reaction of benzonitrile oxide with the magnesium alkoxides of chiral homoallylic alcohols has been shown to proceed with good diastereoselectivity, favoring the syn isomer of the resulting 2-isoxazoline.     

Vibrational relaxation of phenol in benzonitrile and benzene solutions

The Raman bandwidths and the frequency shifts of the ν₁₂(A₁) mode and the IR ν₃(OH) stretching mode of phenol and phenol-OD have been measured as a function of concentration in benzonitrile and benzene solutions. Opposite isotope effects of deuterium substitution in the hydroxyl group of phenol on the bandwidths of the ν₁₂ and the ν₃(OH) modes have been found. The experimental bandwidths are discussed in terms of available theoretical models for dephasing and other mechanisms of broadening. The isolated binary collision dephasing model of Fischer-Laubereau, the Knapp-Fischer concentration-fluctuation model and the Robertson-Yarwood model have been tested. It has been stated that the purely repulsive potential is responsible for vibrational dephasing of the ν₁₂ mode of phenol in benzene while the concentration-fluctuation model reproduces the experimental data for that mode in benzonitrile. The coupling between the ν₃(OH) and ν₂(OH…N) modes is the dominant mechanism for broadening of the ν₃(OH) mode of phenol in benzonitrile.     

Tetrazoles. 21. Reaction of benzonitrile with salts of hydrazoic acid

The reaction of benzonitrile with the ammonium, alkyl-, dialkyl-, and trialkylammonium salts of hydrazoic acid in DMF at 100C produces 5-phenyltetrazole. The yield of 5-phenyltetrazole is practically independent of the structure of the ammonium cation. Under the same conditions, the tetraalkylammonium salts of hydrazoic acid do not react with benzonitrile. It was proposed that the formation of 5-substituted tetrazoles from nitriles and the salts of hydrazoic acid proceeds by the mechanism of 1,3-dipolar cycloaddition.For Communication 20, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1086–1089, August, 1986.     

Nonlinear dielectric effect in benzonitrile and lauronitrile solutions

The nonlinear dielectric effect, NDE, and the calculated correlation factors R^p and R^s are reported for binary solutions of benzonitrile and lauronitrile in benzene and cyclohexane. Substantial differences found for solutions in these two solvents have been explained in terms of critical phenomena in cyclohexane solution.     

Cycloadducts of benzonitrile oxide to pyridine. A case of a two-step cycloaddition

Pyridine adds benzonitrile oxide in apolar solvents, affording fair yields of bisadducts III and IV. Quinoline and isoguinoline afford isolable monocycloadducts VIII and IX.     

Molar excess heat capacities and volumes for mixtures of benzonitrile with cyclohexane between 10 and 45°C

The heat capacities and volumes for binary mixtures of benzonitrile with cyclohexane were determined at 10, 25, and 45°C. The dependence of the molar excess heat capacities on temperature and composition are interpreted in terms of the thermal relaxation of associated benzonitrile molecules into monomeric species.To whom correspondence should be addressed.     

Photoreactions of benzonitrile with cyclic enol ethers

Upon irradiation, cyclic enol ethers such as 1-methoxy-cyclopentene (4) mainly add across the cyano group of benzonitrile (1), under formation of 2-azabutadienes of an imidoester type. This is in agreement with the so-called Δ G-correlation which was reported earlier (ref. 5 and 6). 4-Phenyloxazole (9) is formed from 1 and 1,3-dioxole (5) probably by a similar photochemical process followed by electrocyclic ring opening and hydrolysis. The low yield of the latter photoreaction and the almost exergonic electron transfer between 5 and 1 may point to back electron transfer as the main energy wasting process. From 1 and 2,3-dihydrido-furan (2) only the ortho cycloadduct 6 has been isolated in low yields.