Effects of shape,size, and pyrene doping on electronic properties of graphene nanoflakes

Effects of size, shape, and pyrene doping on electronic properties of graphene nanoflakes (GNFs) were theoretically investigated using density functional theory method with PBE, B3PW91, and M06-2X functionals and cc-pVDZ basis set. Two shapes of zigzag GNFs, hexagonal (HGN) and rhomboidal (RGN), were considered. The energy band gap of GNF depends on shape and decreases with size. The HGN has larger band gap energy (1.23–3.96 eV) than the RGN (0.13–2.12 eV). The doping of pyrene and pyrene derivatives on both HGN and RGN was also studied. The adsorption energy of pyrene and pyrene derivatives on GNF does not depend on the shape of GNFs with energies between 21 and 27 kcal mol^?1. The substituent on pyrene enhances the binding to GNF but the strength does not depend on electron withdrawing or donating capability. The doping by pyrene and pyrene derivatives also shifts the HOMO and LUMO energies of GNFs. Both positive (destabilizing) and negative (stabilizing) shifts on HOMO and LUMO of GNFs were seen. The direction and magnitude of the shift do not follow the electron withdrawing and donating capability of pyrene substituents. However, only a slight shift was observed for doped RGN. A shift of 0.19 eV was noticed for HOMO of HGN doped with 1-aminopyrene (pyNH₂) and of 0.04 eV for LUMO of HGN doped with 1-pyrenecarboxylic acid (pyCOOH).

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Graphical Abstract HOMO and LUMO Energies of pyrene/pyrene derivatives doped Graphene Nanoflakes

     

Evaluation of the energetic position of the lowest excited singlet state of beta-carotene by NEXAFS and photoemission spectroscopy.

In carotenoids the lowest energetic optical transition belonging to the pi-electron system is forbidden by symmetry, therefore the energetic position of the S(1) (2(1)A(g)) level can hardly be assessed by optical spectroscopy. We introduce a novel experimental approach: For molecules with pi-electron systems the transition C1s-->2p(pi*) from inner-atomic to the lowest unoccupied molecular orbital (LUMO) appears in X-ray absorption near edge spectra (NEXAFS) as an intense, sharp peak a few eV below the carbon K-edge. Whereas the peak position reflects the energy of the first excited singlet state in relation to the ionization potential of the molecule, intensity and width of the transition depend on hybridization and bonding partners of the selected atom. Complementary information can be obtained from ultraviolet photoelectron spectroscopy (UPS): At the low binding energy site of the spectrum a peak related to the highest occupied molecular orbital (HOMO) appears. We have measured NEXAFS and UPS of beta-carotene. Based on these measurements and quantum chemical calculations the HOMO and LUMO energies can be derived.     

Theoretical study of the electron affinities of the alkaline-earth tetramers possessing T d symmetry: Be4 and Mg4

The electron affinities of beryllium and magnesium tetramers are calculated at the ROMP2 level employing the Dunning-type aug-cc-pVQZ basis set. The vertical electron detachment energy (VEDE) amounts to 1.685 eV for Be₄^– and 0.943 eV for Mg₄ . The decomposition of the VEDE into physical components and an atomic orbital population analysis are used to elucidate the nature of the outer electron binding in these anions.Figure The lowest unoccupied molecular orbitals in the ground state of Mg4 : a LUMO, symmetry A₁, b LUMO + 1, symmetry T₂; c the highest occupied molecular orbital (HOMO), symmetry A1 in the ground state of Mg₄^–.      

Identification of Potential Carbonic Anhydrase Inhibitors for Glaucoma Treatment Through an In-Silico Approach

Glaucoma is a neurodegenerative disease and second leading cause of blindness in western world. The disease is characterized by an elevated intraocular pressure. Carbonic anhydrase plays a major role by forming aqueous humor and its inhibition can reduce intraocular pressure by partially suppressing the secretion of aqueous humor. Thus in this study, we proposed to identify the potential novel compounds targeting the carbonic anhydrase. The diversity set-II molecules library consisting of 1880 compounds from National Cancer Institute were virtually screened (molecular docking) against human carbonic anhydrase protein. For the obtained best compounds, the nature of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), which determine nucleophilic and electrophilic activity, were calculated by using density functional theory (DFT). The in silico screening suggested 5 best compounds that are effective in comparison to the dorzolamide, a widely used carbonic anhydrase inhibitor for glaucoma treatment. Of the five compounds, 4-nitro-7-[(1-oxidopyridin-1-ium-2-yl) thio] benzofurazan (ZINC01757986) exhibited the better binding affinity (??9.2 cal/mol) in comparison to dorzolamide (??7.2 kcal/mol). The DFT studies on novel identified compound, ZINC01757986 exhibited less HOMO–LUMO energy gap, low hardness and more softness (0.2305 eV, 0.1152 eV and 8.6805 eV) when compared to dorzalamide (0.9536 eV, 0.4768 eV and 2.0973 eV). These studies emphasize that ZINC01757986 can be used as potential carbonic anhydrase inhibitor and lead compounds for the development of an effective anti-glaucoma drug. The results emphasize that these compounds could be potential lead molecules for further structure-based discovery of antiglaucoma drugs.

     

Design and synthesis of ferrocene probe molecules for detection by electrochemical methods

A series of ferrocenyl conjugates to fatty acids have been designed and synthesized to establish the key properties required for use in biomolecular binding studies. Amperometric detection of the ferrocene conjugates was sought in the region of 0.3 V (vs Ag/AgCl) for use in protein/blood solutions. Different linkers and solubilizing moieties were incorporated to produce a conjugate with optimal electrochemical properties. In electrochemical studies, the linker directly attached to the ferrocene was found to affect significantly the E(1/2) value and the stability of the ferrocenium cation. Ester-linked ferrocene conjugates had E(1/2) ranging from +400 to +410 mV, while amide-linked compounds ranged from +350 to +370 mV and the amines +260 to +270 mV. Folding of long-chain substituents around the ferrocene, also significantly affected by the choice of linker, was inferred as a secondary effect that increased E(1/2). The stability of the ferrocenium cation decreased systematically as E(1/2) increased. Disubstituted ferrocene ester and amide conjugates, with oxidation potentials of +640 and +570 mV, respectively, showed only a barely discernible reduction wave in cyclic voltammetry at 50 mV/s. Electrochemical measurements identified two lead compounds with the common structural characteristics of an amide and carbamate linker (compounds 17 and 21) with a C(11) fatty acid chain attached. It is envisaged that such molecules can be used to mimic and study the biomolecular binding interaction between fatty acids and molecules such as human serum albumin.     

High‐Performance Aqueous Rechargeable Li‐Ni Battery Based on Ni(OH)2/NiOOH Redox Couple with High Voltage

New energy storage and conversion systems require large‐scale, cost‐effective, good safety, high reliability, and high energy density. This study demonstrates a low‐cost and safe aqueous rechargeable lithium‐nickel (Li‐Ni) battery with solid state Ni(OH)₂/NiOOH redox couple as cathode and hybrid electrolytes separated by a Li‐ion‐conductive solid electrolyte layer. The proposed aqueous rechargeable Li‐Ni battery exhibits an approximately open‐circuit potential of 3.5 V, outperforming the theoretic stable window of water 1.23 V, and its energy density can be 912.6 W h kg^‐1, which is much higher than that of state‐of‐the‐art lithium ion batteries. The use of a solid‐state redox couple as cathode with a metallic lithium anode provides another postlithium chemistry for practical energy storage and conversion.     

On the electronic properties of two-dimensional honeycomb GaInN and GaAlN alloys: a molecular analysis

We have performed first principles total energy calculations to investigate the structural and the electronic properties of two-dimensional honeycomb GaAlN and GaInN alloys. Calculations were done using a coronene-like (C₂₄H₁₂) cluster and for different numbers of Ga, Al, and In atoms. The exchange and correlation potential energies were treated within the generalized gradient approximation (GGA). The bond length, dipole moment, binding energy, and gap between the HOMO and the LUMO are reported as a function of x. The stability of the structures depends on the site of the substituted atom; for example, when three Ga atoms are substituted, the GaInN alloy becomes unstable. The gap in the GaAlN increases from 3.76 eV (GaN) to 4.51 eV (AlN), and in the GaInN decreases to 2.11 eV. The biggest polarity occurs when eight and four Ga atoms are substituted, for GaAlN and GaInN, respectively.     

Quantum chemical study in the direction to design efficient donor-bridge-acceptor triphenylamine sensitizers with improved electron injection

The ground state geometries have been computed by using density functional theory. The excitation energies for dye sensitizers were performed by using time dependant density functional theory. The polarizable continuum model (PCM) has been used for evaluating bulk solvent effects at all stages. The calculations have been carried out in methanol according to the experimental set up. The long-range-corrected functional (PCM-TD-LC-BLYP) underestimate the absorption spectrum of parent molecule while PCM-TDBHandHLYP is in good agreement with the experimental data. The highest occupied molecular orbital (HOMO) is delocalized on TPA moiety while lowest unoccupied molecular orbital (LUMO) is localized on anchoring group, conjugated chain and the benzene ring near to the anchoring group. The LUMO energies of all the investigated dyes are above the conduction band of TiO(2), HOMOs are below the redox couple and HOMO-LUMO energy gaps of studied dyes are smaller compared to TC4. The 1 and 3 are 7 and 12?nm blue shifted while 2 and 4 are 25 and 22?nm red shifted, respectively compared to TC4. The trend of electron injection (ΔG(inject)), relative electron injection (ΔG (r) (inject) ()), and electronic coupling constant (|VRP|) has been observed as 3?>?1?>?4?>?2?>?TC4. The improved ΔG(inject), |VRP| and light harvesting efficiency (LHE) of new designed sensitizers revealed that these materials would be excellent sensitizers. The broken coplanarity between the benzene near anchoring group having LUMO and the last benzene attached to TPA unit in 1-4 consequently would hamper the recombination reaction.     

Functionalized pyrene‐based AIEgens: synthesis,photophysical characterization and density functional theory studies

Three new pyrene‐based derivatives P1 , P2 and P3 with a substituted pyrazole were designed, synthesized and characterized using standard spectroscopic techniques. Ultraviolet–visible (UV–vis) spectroscopic studies for P1–P3 uncovered a finite bathochromic shift of the molecules in solvents of varying polarity. Photoluminescence (PL) studies revealed the significant fluorescence emission of all molecules in higher polar solvents such as MeOH and dimethylformamide (DMF). Fluorescence quantum yield studies demonstrated the importance of P3 possessing cyanofunctionality for imparting higher emission with a quantum yield of 0.36%. Ratiometric studies performed in a tetrahydrofuran (THF)/H₂O mixture indicated fluorescence enhancement with increasing overall percentage of water, confirming the aggregation‐induced emission effect. Cyclic voltammetry study of molecules P1–P3 revealed an irreversible oxidation peak and the band gaps were calculated to be 2.26 eV for P1 and 2.31 eV for P2 and P3 respectively. Density functional theory (DFT) studies performed on molecules P1–P3 validate the structure correlation of the molecules. Theoretically estimated highest occupied molecular orbital ( HOMO), lowest unoccupied molecular orbital (LUMO) and bandgap correlated well with the experimental values. Furthermore, time‐dependent (TD)DFT showed that the major contribution for the electronic transitions occurring in the system was governed by HOMO‐1 and LUMO+1 orbitals.     

Photophysical and structural aspects of perylene‐doped 2‐naphthol luminophors: Green emission by exciplex formation

Several perylene (Pery)‐doped 2‐naphthol (2‐NP) (Pery/2‐NP) luminophors were prepared using conventional solid‐state reaction techniques. Energy transfer in the excited state was examined using fluorescence spectroscopy and cyclic voltammetry. Fluorescence studies revealed exciplex formation by Pery in the form of structureless and broad spectra at higher concentrations with monomer quenching of 2‐NP; a broad green emission was observed in the range 500–650 nm, peaking at 575 nm. Structural properties and thermal stability were analyzed using X‐ray diffraction, scanning electron microscopy and TGA‐differential scanning calorimetry. Highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels were observed in the range 5.56–5.61 eV and 2.79–2.81 eV, respectively with a 2.77–2.82 eV band gap. The present study reveals these to be probable candidates for hole‐transporting materials suitable in optoelectronics.     

TD-M06-2X insights into the absorption and emission spectra of dichlorvos and its molecularly imprinted recognition by methacrylic acid

The absorption and emission spectra of dichlorvos and the dichlorvos-MAA complex in methanol, water, and chloroform in the molecularly imprinted recognition were investigated systematically. The M06-2X results revealed that: 1) the hydroxyl groups in polar solvents such as methanol and water may markedly influence the weak interactions, and then alter the adsorption and emission spectra; 2) the electronic excitation in absorption spectra of dichlorvos is dominated by the configuration HOMO?→?LUMO, but in the most stable dichlorvos-MAA it becomes the ππ* excitation of HOMO?→?LUMO?+?1; 3) Mulliken charges reveal that dichlorvos almost dissociates to Cl^- and a cation in its S₁ excitation state; 4) the phosphorescence spectra of dichlorvos-MAA are relatively weak.

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Graphical Abstract The absorption and emission spectra of dichlorvos and the dichlorvos-MAA complex in the molecularly imprinted recognition of dichlorvos were investigated systematically in methanol, water, and chloroform as solvents.

     

Molecular orbital theory on cellulolytic reactivity between pNP-cellooligosccharides and beta-glucosidase from Cellulomonas uda CS1-1

A beta-glucosidase with the molecular mass of 160,000 Da was purified to homogeneity from cell extract of a cellulolytic bacterium, Cellulomonas uda CS1-1. The kinetic parameters (Km and Vmax) of the enzyme were determined with pNP-cellooligosccharides (DP 1-5) and cellobiose. The molecular orbital theoretical studies on the cellulolytic reactivity between the pNP-cellooligosaccharides as substrate (S) molecules and the purified beta-glucosidase (E) were conducted by applying the frontier molecular orbital (FMO) interaction theory. The results of the FMO interaction between E and S molecules verified that the first stage of the reaction was induced by exocyclic cleavage, which occurred in an electrophilic reaction based on a strong charge-controlled reaction between the highest occupied molecular orbital (HOMO) energy of the S molecule and the lowest occupied molecular orbital (LUMO) energy of the hydronium ion (H3O+), more than endocyclic cleavage, whereas a nucleophilic substitution reaction was induced by an orbital-controlled reaction between the LUMO energy of the oxonium ion (SH+) protonated to the S molecule and the HOMO energy of the H2O2 molecule. A hypothetic reaction route was proposed with the experimental results in which the enzymatic acid-catalyst hydrolysis reaction of E and S molecules would be progressed via SN1 and SN2 reactions. In addition, the quantitative structure-activity relationships (QSARs) between these kinetic parameters showed that Km has a significant correlation with hydrophobicity (logP), and specific activity has with dipole moment, respectively.     

Adsorption of tetracyanoquinodimethane and tetrathiafulvalene on aluminium (100) surface – a first principle study of structural and electronic properties

Possible adsorption configurations and electronic properties, such as charge analysis, density of states, work function and Schottky barrier height of tetracyanoquinodimethane (TCNQ) and tetrathiafulvalene (TTF) on Aluminium (100) surface is studied by using density functional theory methods with local density approximation (LDA), generalised gradient approximation (GGA), PBE and PBE-D2 methods. TCNQ is strongly adsorbed on Al(100) with adsorption energy of ?3.66?eV. The charge is transferred from Al(100) to TCNQ and charge transfer occurs mainly through cyano group of TCNQ. Adsorption on Al(100) surface leads to downshift in energy difference between highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of TCNQ by 2.5?eV as result of hybridisation of p orbital of carbon and nitrogen atoms of TCNQ and p orbital of surface Al atoms. Compared to TCNQ adsorption, TTF adsorption on Al(100) surface is having less adsorption energy and type of interaction is physisorption. The charge transfer from TTF to Al(100) surface leads to decrease in work function of Al by 0.24?eV. The n-type Schottky barrier height of TCNQ/Al(100) and p-type Schottky barrier height of TTF/Al(100) is 0.68eV and 1.97?eV, respectively showing that TCNQ and Al(100) are suitable for organic photovoltaic and electrochemical applications.     

Valence tautomerism and macrocycle ruffling in nickel(III) porphyrins

Nonlocal density functional calculations with full geometry optimization have been carried out on the low-lying electronic states of oxidized nickel porphyrins. For [NiIII(P)(Py)2]+, the ground state corresponds to a t2g6(z2)1 configuration and the t2g6(x2-y2)1 configuration is 0.43 eV higher in energy. In contrast, the ground state of [NiIII(P)(CN)2]- corresponds to a t2g6(x2-y2)1 configuration, the t2g6(z2)1 configuration being 0.96 eV higher in energy. The results are consistent with EPR spectroscopic results on the TPP analogs of these complexes. For [Ni(P)(Py)2]+, the a2u- and a1u-type Ni(II) porphyrin cation radical states are higher in energy by 0.63 and 1.23 eV, respectively, relative to the t2g6(z2)1 Ni(III) ground state. The Ni-N(Porphyrin) distance is significantly shorter in [NiIII(P)(Py)2]+ (196 pm) than in [NiIII(P)(CN)2]- (206 pm), which is consistent with the ruffled and planar macrocycle conformations, respectively, in the two complexes.     

DFT calculation of the electronic properties of fluorene-1,3,4-thiadiazole oligomers

Thiadiazole derivatives have been widely employed in the areas of pharmaceutical, agricultural, industrial, and polymer chemistry. The electronic and molecular structures of thiadiazoles are of interest because they have an equal number of valence electrons and similar molecular structures to thiophenes, which are currently used in the construction of organic solar cells due to their relatively high hole mobilities and good light-harvesting properties. For this reason, the electronic properties of fluorene-1,3,4-thiadiazole oligomers warrant investigation. In the present work, the structure of fluorene-1,3,4-thiadiazole with one thiadiazole unit in the structure was analyzed. This molecule was then expanded until there were 10 thiadiazole units in the structure. The band gap, HOMO and LUMO distributions, and absorption spectrum were analyzed for each molecule. All calculations were performed by applying the B3LYP/6-31G(d) chemical model in the Gaussian 03W and GaussView software packages. The electronic properties were observed to significantly enhance as the number of monomeric units increased, which also caused the gap energy to decrease from 3.51 eV in the oligomer with just one thiadiazole ring to 2.33 eV in the oligomer with 10 units. The HOMO and LUMO regions were well defined and separated for oligomers with at least 5 monomer units of thiadiazole.

New unsymmetric dinuclear Cu(II)Cu(II) complexes and their relevance to copper(II) containing metalloenzymes and DNA cleavage

The new homodinuclear complexes, [Cu(2)(II)(HLdtb)(mu-OCH(3))](ClO(4))(2) (1) and [Cu(2)(II)(Ldtb)(mu-OCH(3))](BPh(4)) (2), with the unsymmetrical N(5)O(2) donor ligand (H(2)Ldtb) - {2-[N,N-Bis(2-pyridylmethyl)aminomethyl]-6-[N',N'-(3,5-di-tert-butylbenzyl-2-hydroxy)(2-pyridylmethyl)]aminomethyl}-4-methylphenol have been synthesized and characterized in the solid state by X-ray crystallography.In both cases the structure reveals that the complexes have a common {Cu(II)(mu-phenoxo)(mu-OCH(3))Cu(II)} structural unit.Magnetic susceptibility studies of 1 and 2 reveal J values of -38.3 cm(-1) and -2.02 cm(-1), respectively, and that the degree of antiferromagnetic coupling is strongly dependent on the coordination geometries of the copper centers within the dinuclear {Cu(II)(mu-OCH(3))(mu-phenolate)Cu(II)} structural unit.Solution studies in dichloromethane, using UV-Visible spectroscopy and electrochemistry, indicate that under these experimental conditions the first coordination spheres of the Cu(II) centers are maintained as observed in the solid state structures, and that both forms can be brought into equilibrium ([Cu(2)(HLdtb)(mu-OCH(3))](2+)=[Cu(2)(Ldtb)(mu-OCH(3))](+)+H(+)) by adjusting the pH with Et(3)N (Ldtb(2-) is the deprotonated form of the ligand).On the other hand, potentiometric titration studies of 1 in an ethanol/water mixture (70:30 V/V; I=0.1M KCl) show three titrable protons, indicating the dissociation of the bridging CH(3)O(-) group.The catecholase activity of 1 and 2 in methanol/water buffer (30:1 V/V) demonstrates that the deprotonated form is the active species in the oxidation of 3,5-di-tert-butylcatechol and that the reaction follows Michaelis-Menten behavior with k(cat)=5.33 x 10(-3)s(-1) and K(M)=3.96 x 10(-3)M. Interestingly, 2 can be electrochemically oxidized with E(1/2)=0.27 V vs.Fc(+)/Fc (Fc(+)/Fc is the redox pair ferrocinium/ferrocene), a redox potential which is believed to be related to the formation of a phenoxyl radical.Since these complexes are redox active species, we analyzed their activity toward the nucleic acid DNA, a macromolecule prone to oxidative damage.Interestingly these complexes promoted DNA cleavage following an oxygen dependent pathway.     

Donor-enhanced bridge effect on the electronic properties of triphenylamine based dyes: density functional theory investigations

The geometries have been optimized by using density functional theory. The highest occupied molecular orbitals are delocalized on triphenylamine moiety while lowest unoccupied molecular orbital are localized on anchoring group. Intramolecular charge transfer has been observed from highest occupied molecular orbitals to lowest unoccupied molecular orbital. By replacing the vinyl hydrogens with methoxy as well as one benzene ring as bridge leads to a raised energy gap while extending the bridge decreases the energy gap compared to parent molecule. The HOMO energies bump up by extending the bridge. The LUMO energies of all the investigated dyes are above the conduction band of TiO(2) and HOMOs are below the redox couple except 3c. The distortion between anchoring group and triphenylamine can hamper the recombination reaction.     

Electronic and molecular structure of M-DNA fragments

To study M-DNA molecular structure (such DNA with transition metal ions placed between the nucleic bases is able to conduct the electric current) and its conductivity mechanisms, we carried out ab initio quantum-mechanical calculations of electronic and spatial structures, thermodynamic characteristics of adenine-thymine (АТ) and guanine-cytosine (GC) base pair complexes with Zn²⁺ and Ni²⁺. To take into account the influence of the alkaline environment, calculations for these complexes were also carried out with hydroxyl and two water molecules. Computations were performed at MP2 level of theory using 6–31+G* basis set. Analogous calculations were carried out for (AC)(TG) stacking dimer of nucleic acid base pairs with two Zn²⁺. The calculation of the interaction energy in complexes has shown the preference of locating the metal ion (instead of the imino proton) between bases in M-DNA. The electronic transition energy calculation has revealed the reduction of the first singlet transition energy in АТ and GC complexes with Ni²⁺ from 4.5 eV to 0.4 - 0.6 eV. Ni²⁺ orbitals take part in the formation of HOMO and LUMO on the complexes investigated. It was shown that charges of metal ions incorporated into complexes with nucleic bases and in dimer decrease significantly.     

Carbon nanotube functionalization with carboxylic derivatives: a DFT study

Chemical functionalization of a single-walled carbon nanotube (CNT) with different carboxylic derivatives including –COOX (X?=?H, CH₃, CH₂NH₂, CH₃Ph, CH₂NO₂, and CH₂CN) has been theoretically investigated in terms of geometric, energetic, and electronic properties. Reaction energies have been calculated to be in the range of ?0.23 to ?7.07 eV. The results reveal that the reaction energy is increased by increasing the electron withdrawing character of the functional groups so that the relative magnitude order is ?CH₂NO₂?>?CH₂CN?>?H?>?CH₂Ph?>?CH₃?>?CH₂NH₂. The chemical functionalization leads to an increase in HOMO/LUMO energy gap of CNT by about 0.32 to 0.35 eV (except for ?H). LUMO, HOMO, and Fermi level of the CNT are shifted to lower energies especially in the case of ?CH₂NO₂ and _?CH₂CN functional groups. Therefore, it leads to an increment in work function of the tube, impeding the field electron emission.     

Electrical conduction through DNA molecule

Several disorder parameters, inside the DNA molecule, lead to localization of charge carriers inside potential wells in the lowest unoccupied and highest occupied molecular orbits (LUMO and HOMO) which affects drastically the electrical conduction through the molecule, and demonstrates that the band carriers play an essential role in the conduction mechanism. So, a model is presented to shed light on the role of electrons of the LUMO in the electrical conduction through the DNA molecule. DC-, AC-conductivity and dielectric permittivity experimental data are well fitted with the presented model giving evidence that the free carriers in the LUMO and HOMO are responsible to make the DNA molecule conductor, insulator or semiconductor. The obtained results show that the localized charge carriers in the DNA molecule are characterized by four different types of relaxation phenomena which are thermally activated by corresponding four activation energies at 0.56 eV, 0.33 eV, 0.24 eV, and 0.05 eV respectively. Moreover, the calculations after the model, at room temperature, show that the time of the relaxation times of the current carriers are in the order of 5 × 10⁻² s, 1.74 × 10⁻⁴ s, 5 × 10⁻⁷ s, and 1.6 × 10⁻¹⁰ s, respectively.