Anion‐aided Dynamic One‐pot Self‐assembly of Rectangular Metallacycles

The tetracopper(I) complex [{Cu₂(μ‐dppm)₂}₂(μ‐1,4‐O₂CC₆H₄ (CO₂ )₂)](BF₄ )₂ ( 1 (BF₄ )₂) and 1,2‐bis(4‐pyridyl)ethane (bpa) can establish a dynamic equilibrium in CH₂Cl₂ . From the equilibrium mixture containing 1 (BF₄ )₂ and bpa with the molar ratio 1 (BF₄ )₂/bpa of 1:1, a supramolecular compound [{Cu₂(μ‐dppm)₂}₂(μ‐1,4‐C₆H₄ (CO₂ )₂)(μ‐bpa)]₂(BF₄ )₄ ( 2 (BF₄ )₄) was obtained as single crystals. The crystal structure was determined by X‐ray crystallography to reveal presence of one anion inside a cationic rectangular metallacycle { 2 ⊂ BF₄ }³⁺. Both structural evidence and DFT ‐calculated results indicate that the F atoms of the anion exert weak electrostatic attraction with hydrogen atoms of the bound bpa as the framework of the cationic metallacycle. The attractive interactions apparently play an important role in stabilizing some dynamically self‐assembled precursors so as to form the final anion‐included metallacycle. Without the electrostatic help from the anion, the self‐assembly of the empty metallacycle may be hindered by a rather large endothermic free energy. The favorable electrostatic stabilization is present not only for a anion but also for other anions such as , , and even when the flexible bpa is replaced by rigid 4,4′‐bipyridine (bpy). Based on the DFT results, the metallacycle 2 (BF₄ )₄ can be easily prepared in a one‐pot reaction of [Cu(MeCN )₄](BF₄ ) with three ligands.     

Bending Vibrational Levels in the Electronic Spectra of Small Radicals

The role played by bending vibrations in the spectroscopy of small carbon‐containing radicals is illustrated by the patterns and effects shown by C₃, CCH, and C₃Ar. Because of the large change in the bending frequency between the ¹Σ⁺_g and ¹Π_u states of C₃, the ¹Π_u state provides one of the best known examples of the coupling of electronic and vibrational motion in linear molecules (the Renner–Teller effect). The ²Σ⁺ and ²Π states of CCH provide a classic instance of vibronic coupling between two close‐lying electronic states, which leads very rapidly to a chaotic pattern of mixed‐state vibrational energy levels, which can only be understood by extensive high‐quality ab initio calculations. C₃Ar is an approximately T‐shaped molecule with no less than four large‐amplitude vibrations. Its state provides a beautiful example of what happens to the angular momentum of a Π state of C₃ when the symmetry is lowered by complex formation.     

Green's Function and Eigenvalue Representation of Time Lag for Absorptive Permeation Across a Heterogeneous Membrane

The time‐lag problem is treated for absorptive penetration across a heterogeneous membrane, where both the diffusivity D (x ) and the partition coefficient K (x ) depend on the coordinate x (0 ≦ x ≦ h ), with 0 and h being the coordinates of the upstream and downstream faces, respectively. A new concept of time‐lag distribution is introduced, and the first (time) moment and the second (time) moment over this distribution are also difined and treated in the Lapalce domain in conjuction with the Green's function G (x ,y ), and eigenvalues associated with the time‐independent diffusion equation subject to the absorbing boundary condition at both ends of the membrane. Our central results include and , where λ _i is the i th eigenvalue of the aforementioned diffusion equation. The merits of these new resprentations and comparison with the treatments of Frisch or Eyring are also discussed.     

Synthesis,structural analysis,spectral investigations,and DFT calculations of 1‐(3‐amino‐4‐thia‐1,2‐diazaspiro[4.11]hexadec‐2‐en‐1‐yl)ethan‐1‐one

1‐(3‐amino‐4‐thia‐1,2‐diazaspiro[4.11]hexadec‐2‐en‐1‐yl)ethan‐1‐one was synthesized and experimentally characterized by using FT‐IR, ¹H NMR, ¹³C NMR, and UV–Vis spectroscopy. The structure of the compound was confirmed by single‐crystal X‐ray diffraction. In the crystal structure, the molecules are linked by pairs of N‐H⋯N hydrogen bonds, forming centrosymmetric dimers with the graph‐set motif. The water molecule also plays an important role in the stabilization of the crystal structure, bridging the dimers to form a two‐dimensional supramolecular network. The molecular geometry, frontier molecular orbitals, vibrational frequencies, electronic properties, and molecular electrostatic potential were calculated using density functional theory (DFT) with the B3LYP/6‐311G(d,p) basis set. Geometric parameters, vibrational assignments, and electronic properties such as calculated energies, excitation energies, and oscillator strengths were compared with the experimental data, and it was seen that the theoretical results support the experimental parameters.     

Synthesis and Structures of d10–d10 M2(μ‐dppm)2 Complexes with Sensitive Metal–Metal Distances in Response to the Binding of Sigma Donors

Diphosphine‐bridged dicopper(I) acetate complexes [Cu₂(μ‐dppm)₂(μ‐OAc)]X ( 2 X; X^? = , ) and [Cu₂(μ‐dppm)₂(μ‐OAc)(MeCN)]X ( 4 X) were prepared and the structures of 2 (PF₆ ) and 4 (PF₆ ) determined by X‐ray crystallography. The ground‐state geometries of [Cu₂(μ‐dppm)₂(μ‐OAc)]⁺ and [Cu₂(μ‐dppm)₂(μ‐OAc)(L)]⁺ (L = py, MeCN, THF, acetone, MeOH) were also obtained using density functional theory (DFT). The increased Cu – Cu distances found experimentally and theoretically by comparing the structures of cation [Cu₂(μ‐dppm)₂(μ‐OAc)]⁺ and its derivatives [Cu₂(μ‐dppm)₂(μ‐OAc)(L)]⁺ reflect the binding of various sigma donors (L). When using [Cu₂(μ‐dppm)₂(μ‐OAc)]⁺ as a structure sensor, the electron‐donating strength of a sigma donor can be quantitatively expressed as a DFT‐calculated Cu – Cu distance with the relative strength in the order py > MeCN > THF > acetone > MeOH, as determined.     

Mechanochemical Synthesis of 3d Transition‐Metal–1,2,4‐Triazole Complexes as Precursors for Microwave‐Assisted and Thermal Conversion to Coordination Polymers with a High Influence on the Dielectric Properties

The complexes [MCl₂(TzH)₄] (M=Mn ( 1 ), Fe ( 2 ); TzH=1,2,4‐1H‐triazole) and [ZnCl₂(TzH)₂] ( 3 ) have been obtained by mechanochemical reactions of the corresponding divalent metal chloride and 1,2,4‐1H‐triazole. They were successfully used as precursors for the formation of coordination polymers either by a microwave‐assisted reaction or by thermal conversion. For manganese, the conversion directly yielded [MnCl₂TzH] ( 4 ), whereas for the iron‐containing precursor, [FeCl₂TzH] ( 6 ), was formed via the intermediate coordination polymer [FeCl(TzH)₂]Cl ( 5 ). For cobalt, the isotypic polymer [CoCl(TzH)₂]Cl ( 7 ) was obtained, but exclusively by a microwave‐induced reaction directly from CoCl₂. The crystal structures were resolved from single crystals and powders. The dielectric properties were determined and revealed large differences in permittivity between the precursor complexes and the rigid chain‐like coordination polymers. Whereas the monomeric complexes exhibit very different dielectric behaviour, depending on the transition metal, from “low‐k” to “high‐k” with the permittivity ranging from 4.3 to >100 for frequencies of up to 1000 Hz, the coordination polymers and complexes with strong intermolecular interactions are all close to “low‐k” materials with very low dielectric constants up to 50 °C. Therefore, the conversion procedures can be used to deliberately influence the dielectric properties from complex to polymer and for different 3d transition‐metal ions.     

Theoretical prediction of the optical rotation of chiral molecules in ordered media: A computational study of (Ra)‐1,3‐dimethylallene, (2R)‐2‐methyloxirane,and (2R)‐N‐methyloxaziridine

A theoretical procedure has been developed and implemented to calculate the optical rotation of chiral molecules in ordered phase via origin‐independent diagonal components , of the optical activity tensor and origin‐independent components , for , of the mixed electric dipole‐electric quadrupole polarizability. Origin independence was achieved by referring these tensors to the principal axis system of the electric dipole dynamic polarizability at the same laser frequency ω. The approach has been applied, allowing for alternative quantum mechanical methods based on different gauges, to estimate near Hartree–Fock values for three chiral molecules, (2R)‐N‐methyloxaziridine C₂NOH₅, (2R)‐2‐methyloxirane (also referred to as propylene oxide) C₃OH₆, and ( )‐1,3‐dimethylallene C₅H₈, at two frequencies. The theoretical predictions can be useful for an attempt at measuring correspondent experimental values in crystal phase. © 2015 Wiley Periodicals, Inc.     

DSC Kinetics Analysis for the Synthesis of Three‐Arms Poly(ε‐caprolactone) Using Aluminum Tri‐sec‐Butoxide as Initiator

The kinetics of the ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL) initiated by soluble aluminum tri‐sec‐butoxide (Al(OsecBu)₃) has been investigated by the differential scanning calorimetry (DSC). The DSC polymerizations were carried out under nonisothermal and isothermal conditions to obtain three‐arms poly(ε‐caprolactone) (PCL). From nonisothermal DSC, the polymerization rate (dα/dt) increased with increasing heating rates. The values of E_a were determined from Kissinger ( kJ mol^?1), Friedman (31.0 – 63.0 kJ mol^?1), and Starink (64.0 – 71.0 kJ mol^?1) methods. From isothermal DSC, the dα/dt and the apparent rate constant (k_app) increased with increasing polymerization temperatures. The ROP of ε‐CL initiated by Al(OsecBu)₃ occurred via the coordination insertion mechanism. The number average molecular weight () and percent yield of the synthesized PCL was enhanced by increasing polymerization temperature. The synthesized PCL with of 2.4 × 10⁴ was obtained using a molar ratio of monomer to Al‐O active center ([M]/[Al‐O]) of 400 at 150ºC for 24 h. Al(OsecBu)₃ is one of the promising initiator due to its solubility, low transesterification reaction, and high efficiency in ε‐CL polymerization.     

Solvent Effects on the Monomer/Hydrogen‐Bonded Dimer Equilibrium in Carboxylic Acids: (+)‐(S)‐Ketopinic Acid as a Case Study

The hydrogen‐bond‐assisted self‐association process of a chiral semirigid carboxylic acid, namely, (+)‐(S)‐ketopinic acid, has been studied. The multiconformational monomer/dimer equilibrium has been evaluated by means of a concentration‐dependent FTIR study that enabled the experimental equilibrium constants of the dimer formation reaction (K_dim) to be determined in two solvents of different polarity. In CDCl₃, dimeric forms predominate, even in diluted solutions ( =5.074), whereas in CD₃CN the self‐association process is hindered and monomers are always the main species, irrespective of solute concentration ( =0.194). The reliability of the dimerization constants and the derived mono‐ and dimeric experimental fractions have been proven by means of accurate matching between the experimental vibrational circular dichroism spectra of the species and the theoretical spectra generated by considering the simultaneous weighted contributions of the concomitant monomers and dimers.     

Ruthenium(II) complexes bearing pyridine‐based tridentate and bidentate ligands: catalytic activity for transfer hydrogenation of aryl ketones

Ru(II) complexes of the general formula [RuCl₂(′′)(L)] (1: ′N = N_b, L = MeOH; 2: ′N = N_b, L = CH₃CN; 3: ′N = N_d, L = CH₃CN; 4: ′N = N_p, L = CH₃CN), [Ru(p‐cymene)(_a–b)Cl]Cl (5a: N N_a = 2,2′‐bipyridine; 5b: N N_b = 4,4′‐dimethyl–2,2′‐bipyridine), [Ru(′′)(_a–b)Cl]Cl (6a: ′N = N_b, _a = 2,2′‐bipyridine; 6b: ′N = N_b, _b = 4,4′‐dimethyl‐2,2′‐bipyridine; 7a: ′N = N_d, _a = 2,2′‐bipyridine; 7b: ′N = N_d, _b = 4,4′‐dimethyl‐2,2′‐bipyridine; 8a: ′N = N_p, _a = 2,2′‐bipyridine; 8b: ′N = N_p, _b = 4,4′‐dimethyl‐2,2′‐bipyridine) and [Ru(′′)(_a)Cl]BF₄ (9a: ′N = N_b; _a = 2,2′‐bipyridine) were synthesized from the corresponding [RuCl₂(p‐cymene)]₂ dimer, ′′ and _a–b ligands. The compounds were characterized by elemental analysis, IR and NMR. Complex 9a was studied by X‐ray diffraction, confirming its cationic‐mononuclear [RuCl(_bb)(_a)]⁺ nature. The synthesized Ru(II) complexes (1–8) were employed as catalysts for the transfer hydrogenation of ketones to secondary alcohols in the presence of KOH using 2‐propanol as a hydrogen source at 82°C. The rates of the transfer hydrogenation reactions strongly depended on the type of and ancillary ligands. Copyright © 2012 John Wiley & Sons, Ltd.     

Coordination Behavior of N‐Donor Schiff Base Derived from 2‐Benzoylpyridine Toward Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), and Cr(III) Metal Ions: Synthesis,Spectroscopic and Thermal Studies,and Biological Activity

A new Schiff base was prepared from the reaction of 4,4′‐methylenedianiline with 2‐benzoylpyridine in 1:2 molar ratio, as well as its different metal chelates. The structures of the ligand and its metal complexes were studied by elemental analyses, spectroscopic methods (infrared [IR ], ultraviolet–visible [UV –vis], ¹H nuclear magnetic resonance [NMR ], electron spin resonance [ESR ]), magnetic moment measurements, and thermal studies. The ligand acts as tetradentate moiety in all complexes. Octahedral geometry was suggested for Mn(II ), Cu(II ), Cr(III ), and Zn(II ) chloride complexes and pentacoordinated structure and square planar geometry for Co(II ), Ni(II ), Cu(NO₃ )₂, CuBr₂ , and Pd(II ) complexes. ESR spectra of copper(II ) complexes ( 4 )–( 6 ) at room temperature display rhombic symmetry for complex ( 4 ) and axial type symmetry for complexes ( 5 ) and ( 6 ), indicating ground state for Cu(II ) complexes. The derivative thermogravimetric (DTG ) curves of the ligand and its metal complexes were analyzed by using the rate equation to calculate the thermodynamic and kinetic parameters, which indicated strong binding of the ligand with the metal ion in some complexes. Also, some of these compounds were screened to establish their potential as anticancer agents against the human hepatic cell line Hep‐G₂ . The obtained IC₅₀ value of the copper(II ) bromide complex (4.34 µg/mL ) is the highest among the compounds studied.     

Mass‐Selected Circular Dichroism of Supersonic‐Beam‐Cooled [D4]‐(R)‐(+)‐3‐Methylcyclopentanone

UV spectroscopy and electronic circular dichroism (ECD) experiments on supersonic‐beam‐cooled deuterated (R)‐(+)‐3‐methylcyclopentanone ([D₄]‐(R)‐(+)‐3‐MCP) have been performed by using a laser mass spectrometer. The spectral resolution not only allowed excitation and CD measurements for single vibronic transitions but also for the rotational P, Q, and R branches of these transitions. The investigated transition showed the largest anisotropy factor ever observed for chiral molecules in the gas phase, which, due to residual saturation of the excited transition, represents only a lower limit for the real anisotropy factor. Furthermore, one‐color (1+1+1) and two‐color (1+1′) resonance‐enhanced multiphoton ionization (REMPI) measurements were performed and the effusive‐beam (room temperature) and supersonic‐beam results for [D₄]‐(R)‐(+)‐3‐MCP were compared. These results allowed a differentiation between single‐step ECD (comparable to conventional ECD) and cumulative ECD (only possible in multiphoton excitation) under supersonic‐beam conditions.     

Energies for cyclic and acyclic aggregations of adamantane and diamantane units sharing vertices,edges, or six‐membered rings

Diamondoids are hydrocarbons having a carbon scaffold comprised from polymer‐like composites of adamantane cages. This article describes computed total energies and “SWB‐tension” energies (often referred to as “strain” energies) for species having n adamantane or diamantane units sharing pairwise: one carbon atom (spiro‐[n]adamantane or spiro‐[n]diamantane); one C? C bond (one‐bond‐sharing‐[n]adamantane or one‐bond‐sharing‐[n]diamantane); or one chair‐shaped hexagon of carbon atoms (1234‐helical‐cata‐[n]diamantanes). Each of the five investigated polymer‐like types is considered either as an acyclic or a cyclic chain of adamantane‐ or diamantane‐unit cages. With increasing n values, SWB‐tension energies for acyclic aggregates are found to increase linearly, while the net SWB‐tension energies of cyclic aggregates often go thru a minimum at a suitable value of . In all five cases, a limiting common energy per unit ( ) is found to be approached by both cyclic and acyclic chains as , as revealed from plots of versus 1/n for acyclic chains and of versus 1/n² for cyclic chains. © 2015 Wiley Periodicals, Inc.     

(Rg = He ∼ Rn,n = 1–4): In quest of the potential trapping ability of the aromatic ring

A new series of divalent boron‐rare gas cations (Rg = He ∼ Rn, n = 1–4) have been predicted theoretically at the B3LYP, MP2, and CCSD(T) levels to present the structures, stability, charge distributions, bond natures, and aromaticity. The Rg B bond energies are quite large for heavy rare gases and increase with the size of the Rg atom. Because of steric hindrance new Rg atoms introduced to the B₄ ring will weaken the Rg B bond. Thus in the Rg B bond has the largest binding energy 90–100 kcal/mol. p‐ has a slightly shorter Rg B bond length and a larger bond energy than o‐ . NBO and AIM analyses indicate that for the heavy Rg atoms Ar ∼ Rn the B Rg bonds have character of typical covalent bonds. The energy decomposition analysis shows that the σ‐donation from rare gases to the boron ring is the major contribution to the Rg B bonding. Adaptive natural density partitioning and nuclear‐independent chemical shift analyses suggest that both and have obvious aromaticity.     

Insights into the Kramers’ flux‐over‐population rate for chemical reactions in liquid phases through the matrix transport equation

Kramers’ equation models a chemical reaction as a Brownian particle diffusing over a potential barrier under the influence of medium viscosity. In the case of high viscosity, the equation reduces to a simpler Smoluchowski equation. In this report, we have contrived an equivalent matrix‐transport equation that relates the ordered pair (activity, flux) of the output (activated complex) to that of the input (reactant). With an initial condition of the Dirac delta type placed at the location of the reactant, and a reflecting boundary condition set on the reactant state, and an absorbing boundary condition on the activated complex state, we are able to prove the equality relation between the mean first passage time, , for the diffusion and the inverse of the rate constant, k^?1, for the reaction counterpart. We have also derived , where λ_i is the ith eigenvalue of the Smoluchowski differential operator stipulated with the above‐mentioned boundary conditions. We have also deduced that, in the long time limit, the number of particles remaining inside the diffusion domain decays exponentially with a relaxation time just the same as the concentration of the reactant does for a first‐order reaction system.     

Substitution Kinetics of [Fe(PDT/PPDT)n(phen)m]2+ (n ≠ m; n,m = 1,2) with 2,2′‐Bipyridine, 1,10‐Phenanthroline,and 2,2′,6,2″‐Terpyridine

The triazines 3‐(2‐pyridyl)‐5,6‐diphenyl‐1,2,4‐triazine (PDT), 3‐(4‐phenyl‐2‐pyridyl)‐5,6‐diphenyl‐1,2,4‐triazine (PPDT), and 1,10‐phenanthroline (phen) were coordinated to the Fe²⁺ ion to form (1) , (2) , , (3) and (4) . The complexes were synthesized and characterized by mass spectroscopy and elemental analysis. The rate of substitution of these complexes by 2,2′‐bipyridine (bpy), 1,10‐phenanthroline (phen), and 2,2′,6,2″‐terpyridine (terpy) was studied in a sodium acetate–acetic acid buffers over the range 3.6–5.6 at 25, 35, and 45°C under pseudo–first‐order conditions. The reactions are first order with respect to the concentration of the complexes. The reaction rates increase with increasing [bpy/phen/terpy] and pH, whereas ionic strength has no influence on the rate of reaction. Plots of k _obs versus [bpy/phen/terpy] and 1/[H⁺] are linear with positive slopes and significant y‐intercepts. This indicates that the reactions proceed by both dissociative as well as associative pathways for which the associative pathway predominates the substitution kinetics. Observed temperature‐depended rate constants at the three temperatures at which substitution reactions were studied together with the protonation constants of the substituting ligands (phen, bpy, terpy) were used to evaluate the specific rate constants (k ₁ and k ₂) and thermodynamic parameters (E_a , ΔH ^#, ΔS ^#, and ΔG ^#). The reactivity order of the four complexes depends on the phenyl groups present on the triazine (PDT/PPDT) molecule. The π‐electrons on phenyl rings stabilizes the charge on the metal center by inductive donation of electrons toward the metal center resulting in a decrease in reactivity of the complex, and the order is 1 < 2 < 3 < 4 . The rate of substitution is also influenced by the basicity of the incoming ligand (bpy/phen/terpy), and it decreased in the order: phen > terpy > bpy. Higher rate constants, low E_a values_, and more negative entropy of activation (−ΔS ^#) values were observed for the associative path, revealing that substitution reactions at the octahedral iron(II) complexes by bpy, phen, and terpy occur predominantly by the associative mechanism. Density functional theory calculations support the interpretations.     

A Visible‐Light‐Triggered Conformational Diastereomer Photoswitch in a Bridged Azobenzene

Ketal‐substituted bridged azobenzenes have been synthesized; these display a symmetrical boat conformation with the ketal in pseudo‐equatorial positions. These bridged Z‐azobenzenes (Z₁) readily photoisomerize to the E‐isomer as well as another Z‐conformer (Z₂) with ketal function on the pseudo‐axial position upon irradiation at 406 nm. The two diastereomeric conformers display distinct physicochemical characteristics. Spectroscopic and NMR investigations supported that interconversion of two conformers occurs via the E‐isomer, with good photochemical quantum yield (Φ =0.45±0.03, Φ =0.33±0.05, Φ =0.37±0.06 and Φ =0.36±0.04). The system shows high photostability and no thermal equilibrium between the two stable Z₁ and Z₂ conformers.     

Hyperbranched Polymers Formed Through Irreversible Step Polymerization of AB2‐Type Monomer with Substitution Effect in a Continuous Flow Stirred‐Tank Reactor (CSTR)

A new Monte Carlo simulation method is proposed for the step polymerization of AB₂‐type monomer conducted in a continuous flow stirred‐tank reactor (CSTR). The effect of the second B group reactivity, represented by the reactivity ratio r is investigated. The degree of branching (DB) at large degree of polymerization (P ) limit, DB_{P →∞} does not change with the mean residence time . The value of DB_{P →∞} becomes larger by increasing r and is larger than the corresponding batch polymerization. The weight fraction distribution at high molecular weight tail follows a power law , and a simple formula to predict the power exponent α is proposed. The relationship between the radius of gyration 〈s ²〉₀ and P does not change with , and large polymers obtained in a CSTR are much more compact than those formed in batch polymerization. CSTR is advantageous to synthesize compact HB polymers, especially with a smaller r‐value.     

Geometric and electronic structures of silicon fluorides (N = 4 – 6) and potential energy surfaces for dissociation reactions → SiF4 + F– and → + F–

The geometric and electronic structures of a series of silicon fluorides (n = 4 ? 6) were computationally studied with the aid of density functional theory (DFT) method with B3LYP and M06‐2X functionals and coupled cluster (CCSD and CCSD(T)) methods with 6‐311++G(d,p) basis set. The nature of the Si‐F bonds in these compounds was analyzed in the framework of the natural bond orbital theory and natural resonance theory. Energy characteristics (heats of reactions and energy barriers) of the dissociation reactions → SiF₄ + F^– and → + F^– were calculated using the DFT and CCSD methods. The potential energy surface of elimination of a fluoride anion from has a specific topology with valley‐ridge inflection points corresponding to bifurcations of the minimal energy reaction path. © 2016 Wiley Periodicals, Inc.     

The Role of Solvation in the Kinetics and the Mechanism of Hydroperoxide Radicals Addition to π‐Bonds of 1,2‐Diphenylethylene and 1,4‐Diphenylbutadiene‐1,3

A combination of microcalorimetry, the rotating sector method, and ESR at 323 K in the environment of 10 solvents of different polarities was used to measure rate constants of addition of hydroperoxide radicals () to π bonds of trans‐1,2‐diphenylethylene and trans,trans‐1,4‐diphenylbutadiene‐1,3 (k₂) and disproportionation rate constants of these radicals (k₃). With increasing dielectric constant of the medium, k₂ values increase from 69 to 410 M⁻¹ · s⁻¹, and k₃ values almost do not change and are in the range of (1.0 ± 0.2) × 10⁸ M⁻¹ · s⁻¹. A linear dependence of logarithm values of rate constants from the dielectric constant of the medium in the coordinates of the Kirkwood–Onsager equation was found that allows to make a conclusion about the effect of nonspecific solvation in the studied systems. The quantum‐chemical analysis (NWChem, DFT B3LYP/6‐311G**) of the detailed mechanism for addition shows that the influence of the medium polarity reflects the superposition of the effects of nonspecific and specific solvation. The scale of the polar effect will depend on how different solvation energies of the transition and the initial reaction complexes. If a value of the solvation energy of the transition complex is larger than the solvation energy of the initial reaction complex, then the reaction rate should increase with an increase of the solvent's polarity and decrease otherwise.