DOI: http://dx.doi.org/10.26510/2394-0859.pbe.2018.04

Research Article

Molecular structure, HOMO, LUMO, MEP, natural bond orbital analysis of benzo and anthraquinodimethane derivatives

Tahar Abbaz1*, Amel Bendjeddou1, Didier Villemin2

1Laboratory of Aquatic and Terrestrial Ecosystems, Org. and Bioorg. Chem. Group, University of Mohamed-Cherif Messaadia, Souk Ahras, 41000, Algeria 2Laboratory of Molecular and Thio-Organic Chemistry, UMR CNRS 6507, INC3M, FR 3038, Labex EMC3, Ensicaen and University of Caen, Caen 14050, France

*For correspondence

Dr. Tahar Abbaz,

Laboratory of Aquatic and Terrestrial Ecosystems, Org. and Bioorg. Chem. Group, University of Mohamed-Cherif Messaadia, Souk Ahras, 41000, Algeria. Email: tahar.abbaz@univ-soukahras.dz

 

 

 

 

 

 

 

 

 

 

 

Received: 20 January 2018

Accepted: 27 February 2018

ABSTRACT

Objective: Optimized molecular structures have been investigated by DFT/B3LYP method with 6-31G (d,p) basis set. Stability of Benzo and anthraquinodimethane derivatives 1-4, hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed by using natural bond orbital (NBO) analysis. Electronic structures were discussed and the relocation of the electron density was determined. Molecular electrostatic potential (MEP), local density functional descriptors has been studied. Nonlinear optical (NLO) properties were also investigated. In addition, frontier molecular orbitals analyses have been performed from the optimized geometries. An ionization potential (I), electron affinity (A), electrophilicity index (ω), chemical potential (µ), electronegativity (χ), hardness (η), and softness (S), have been investigated. All the above calculations are made by the method mentioned above.

Methods: The most stable optimized geometries obtained from DFT/B3LYP method with 6-31G(d,p) basis set were investigated for the study of molecular structures, nonlinear properties, natural bond orbital (NBO), molecular electrostatic potential (MEP) and frontier molecular orbital of Benzo and anthraquinodimethane derivatives.

Results: Reactive sites of electrophilic and nucleophilic attacks for the investigated molecule were predicted using MEP at the B3LYP/6-31G(d,p). Compound 4 possesses higher electronegativity value than all compounds so; it is the best electron acceptor; the more reactive sites for electrophilic attacks are shown in compounds 1 and 4, for nucleophilic attacks are indicated in compounds 2 and 3 and the more reactive sites in radical attacks are detected in compounds 2 and 4.

Conclusions: Compound 1 is softest, best electron donor and more reactive than all compounds. The calculated first order hyperpolarizability was found much lesser than reported in literature for urea.

Keywords: Tetrathiafulvalenes, Density functional theory, Computational chemistry, Electronic structure, Quantum chemical calculations

Introduction

The rational design of new organic molecular materials requires intensive experimental investigations in order to elucidate the relationship existing between molecular structures and solid state properties. In this field, cation radical salts of tetrathiafulvalene (TTF) derivatives are the subject of intense research activities owing to their unusual and exciting electric and magnetic properties.1-4 Such behaviour results from the combination of specific electrochemical and structural properties associated with the chemical structure of the TTF core.

Push-pull chromophores, with the electron donor and acceptor separated by π-conjugating linkers (D–π–A), have been investigated for decades.5 Nevertheless, they continue to attract growing interest in view of their promising optoelectronic properties, in particular their second-order and third-order nonlinear optical (NLO) behavior, and their potential for application as advanced functional materials in molecular devices.6-9 We have prepared several families of new push-pull chromophores featuring intense, batho-chromically shifted intra-molecular charge-transfer (CT) bands, high third-order optical nonlinearities, and interesting redox properties.9-10

The density functional theory (DFT) is an excellent tool to calculate the reasonable infrared, vibrational frequencies, molecular geometries, linear and nonlinear optical etc. properties.11-12 B3LYP functional has been previously shown to provide an excellent compromise between accuracy and computational efficiency of vibrational spectra for large and medium size molecule.13-16

The aim of the work is to investigate the molecular structures and nonlinear properties of Benzo and anthraquinodimethane derivatives 1-4 described in literature.17 The study has been complemented by natural bond orbital (NBO) calculations with an analysis of the electron charge transfer through the intramolecular contacts. Compounds have been predicted. The first hyper-polarizability calculation helps to confirm its NLO response. In addition, the molecular electrostatic potential (MEP), frontier molecular orbital analysis properties were investigated using theoretical calculations. All the calculations done in this work are obtained by DFT/B3LYP method with 6-31G(d,p) basis set.

Materials and Methods

The quantum chemical calculations of benzo and anthraquinodimethane derivatives 1-4 have been performed using the B3LYP level of theory supplemented with the standard 6-31G(d,p) basis set, using the Gaussian 09 program. The entire calculations were performed at DFT levels on personal computer using Gaussian 09W program package, invoking gradient geometry optimization.18,19 Initial geometry generated from standard geometrical parameters was minimized without any constraint in the potential energy surface at DFT level, adopting the standard 6-31G(d,p) basis set.

Results and Discussion

Molecular geometry

The most stable optimized geometry obtained from B3LYP/6-31G(d,p) method and the scheme of numbering of atoms of the molecules benzo and anthraquinodimethane derivatives 1-4 are shown in Figure 1. Molecular symmetry can be used to predict many molecular properties such as its dipole. The most optimized structural parameters (bond length, bond angle and dihedral angles) calculated by B3LYP with 6-31G(d,p) basis set are presented in Tables 1-4.

Molecular electrostatic potential

MEP is related to the ED and is a very useful descriptor in understanding sites for electrophilic and nucleophilic reactions as well as hydrogen bonding interactions.20,21 The electrostatic potential V(r) is also well suited for analyzing processes based on the ''recognition'' of one molecule by another, as in drug-receptor, and enzyme–substrate interactions, because it is through their potentials that the two species first ''see'' each other.22,23 To predict reactive sites of electrophilic and nucleophilic attacks for the investigated molecule, MEP at the B3LYP/6-31G(d,p) optimized geometry was calculated. Potential decreases in the order blue> green> yellow> orange> red. Electrophilic regions are represented by red, nucleophilic by blue and green indicates neutral electrostatic potential. To predict reactive sites for electrophilic or nucleophilic attack for the investigated molecule, the MEP at the B3LYP/6-31G(d,p) optimized geometry was calculated. As can be seen from the Figure 2, these molecules have several possible sites for electrophilic and nucleophilic attacks.

           

               

Figure 1: Optimized molecular structure of benzo and anthraquinodimethane derivatives 1-4. A=Compound 1, B=Compound 2, C=Compound 3, D=Compound 4.

Table 1: Optimized geometric parameters of compound 1.

Bond Length(Å) Bond Angles(°) Dihedral Angles(°)
R(1,3) 1.450 A(2,1,3) 122.204 D(3,1,2,35) 179.999
R(1,36) 1.086 A(2,1,36) 118.763 D(2,1,3,29) 179.997
R(1,2) 1.356 A(3,1,36) 119.032 D(36,1,3,6) 179.996
R(3,29) 1.376 A(1,3,6) 115.592 D(2,4,32,31) 179.998
R(7,8) 1.395 A(8,7,12) 119.362 D(15,9,10,11) 180.000
R(7,12) 1.396 A(8,7,13) 120.456 D(17,18,30,32) 179.995
R(8,9) 1.397 A(12,7,13) 120.181 D(19,31,32,4) 179.993
R(11,12) 1.403 A(7,8,14) 119.466 D(6,5,9,11) 177.859
R(11,27) 1.768 A(7,8,9) 120.409 D(34,5,9,10) 174.260
R(27,29) 1.778 A(9,8,14) 120.123 D(9,5,34,4) 179.697
R(22,26) 1.085 A(8,9,10) 120.409 D(5,6,7,8) 114.513
R(4,5) 1.450 A(10,11,12) 120.228 D(6,7,15,18) 170.857
R(28,29) 1.777 A(10,11,27) 123.300 D(8,7,15,16) 101.546
R(4,32) 1.375 A(12,11,27) 116.47 D(10,9,11,13) 122.550
R(5,6) 1.355 A(11,27,29) 96.600 D(20,19,23,24) 138.512

As seen from the Figure 2 that, in all molecules, the regions exhibiting the negative electrostatic potential are localized near the conjugated aromatic rings while the regions presenting the positive potential are localized vicinity of the aromatic hydrogen atoms.

            

                  

Figure 2: Molecular electrostatic potential surface of benzo and anthraquinodimethane derivatives 1-4.

Table 2: Optimized geometric parameters of compound 2.

Bond Length(Å) Bond Angles(°) Dihedral Angles(°)
R(1,2) 1.392 A(2,1,6) 118.252 D(6,1,2,11) 178.917
R(1,6) 1.406 A(2,1,41) 120.373 D(2,1,6,45) 175.418
R(1,41) 1.509 A(6,1,41) 121.367 D(41,1,6,5) 175.417
R(2,11) 1.082 A(1,2,3) 124.085 D(2,1,41,43) 122.728
R(2,3) 1.408 A(1,2,11) 116.647 D(2,3,4,8) 168.640
R(3,7) 1.477 A(3,2,11) 119.226 D(7,3,4,5) 168.638
R(3,4) 1.431 A(2,3,4) 117.174 D(12,5,6,1) 178.916
R(7,35) 1.381 A(2,3,7) 122.104 D(5,6,45,46) 122.727
R(7,10) 1.450 A(4,3,7) 120.721 D(3,7,10,40) 177.581
R(9,10) 1.350 A(3,4,8) 120.721 D(35,7,10,9) 171.887
R(9,39) 1.084 A(5,4,8) 122.105 D(38,8,9,10) 171.885
R(13,14) 1.395 A(3,7,10) 115.285 D(19,13,14,15) 179.872
R(13,18) 1.397 A(3,7,35) 126.574 D(20,14,15,16) 179.883
R(53,57) 1.086 A(10,7,35) 118.024 D(21,15,16,17) 179.998
R(13,19) 1.085 A(8,9,10) 123.522 D(15,16,17,33) 179.045

Table 3: Optimized geometric parameters of compound 3.

Bond Length (Å) Bond Angles (°) Dihedral Angles (°)
R(1,2) 1.414 A(2,1,6) 118.175 D(6,1,2,11) 179.910
R(1,6) 1.426 A(2,1,41) 122.682 D(41,1,2,3) 179.018
R(1,41) 1.420 A(6,1,41) 119.109 D(2,1,6,39) 176.107
R(2,3) 1.388 A(1,2,3) 123.462 D(2,3,4,8) 166.602
R(2,11) 1.082 A(1,2,11) 116.448 D(7,3,4,5) 166.603
R(3,4) 1.458 A(3,2,11) 120.080 D(3,7,10,48) 176.863
R(3,7) 1.477 A(2,3,4) 117.761 D(35,7,10,9) 170.797
R(13,19) 1.085 A(2,3,7) 122.212 D(4,8,9,47) 176.861
R(7,10) 1.450 A(4,3,7) 120.021 D(19,13,14,15) 179.833
R(7,35) 1.380 A(3,4,5) 117.762 D(20,14,15,16) 179.859
R(9,47) 1.084 A(5,4,8) 122.211 D(21,15,16,17) 179.985
R(13,14) 1.394 A(3,7,10) 115.728 D(15,16,17,33) 178.936
R(13,18) 1.397 A(3,7,35) 125.994 D(16,17,18,34) 179.406
R(14,15) 1.398 A(10,7,35) 118.142 D(16,17,33,35) 176.515
R(17,33) 1.763 A(8,9,10) 123.545 D(29,23,28,27) 179.833

Table 4: Optimized geometric parameters of compound 4.

Bond Length (Å) Bond Angles (°) Dihedral Angles (°)
R(1,2) 1.395 A(2,1,6) 119.839 D(16,1,2,3) 179.802
R(1,6) 1.393 A(2,1,16) 119.746 D(2,1,6,19) 178.396
R(1,16) 1.086 A(6,1,16) 120.394 D(17,2,3,4) 176.271
R(2,3) 1.401 A(1,2,3) 121.072 D(7,3,4,5) 177.477
R(2,17) 1.085 A(1,2,17) 119.286 D(2,3,7,10) 139.466
R(3,4) 1.420 A(3,2,17) 119.599 D(4,3,7,45) 137.951
R(3,7) 1.482 A(2,3,7) 123.379 D(8,4,5,6) 178.703
R(7,45) 1.362 A(4,3,7) 117.497 D(18,5,6,1) 176.269
R(23,28) 1.396 A(3,7,45) 123.339 D(10,7,45,44) 176.016
R(24,25) 1.397 A(4,8,9) 113.186 D(4,8,9,15) 139.469
R(24,30) 1.084 A(4,8,48) 123.337 D(48,8,9,10) 137.954
R(25,26) 1.395 A(10,9,15) 119.073 D(4,8,48,47) 176.021
R(27,28) 1.400 A(12,11,13) 119.287 D(8,9,10,11) 177.479
R(27,43) 1.769 A(24,23,29) 120.470 D(10,9,15,22) 176.274
R(44,45) 1.788 A(28,23,29) 120.219 D(7,10,11,13) 178.705

Frontier molecular orbitals (FMOs)

To explain several types of reaction and for predicting the most reactive position in conjugated systems, molecular orbitals and their properties such as energy are used.24 The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) are the most important orbitals in a molecule. The Eigen values of HOMO and LUMO and their energy gap reflect the biological activity of the molecule. A molecule having a small frontier orbitals gap is more polarizable and is generally associated with a high chemical reactivity and low kinetic stability.25-27 HOMO which can be though as the outer orbital containing electrons, tend to give these electrons as an electron donor and hence the ionization potential is directly related to the energy of the HOMO. On the other hand LUMO can accept electrons and the LUMO energy is directly related to electron affinity.28,29 Two important molecular orbitals were examined for the compound 1, HOMO and LUMO which are given in Figure 3.

Global reactivity descriptors

The global chemical reactivity descriptors such as hardness (η), chemical potential (µ), softness (S), electronegativity (χ) and electrophilicity index (ω) of the titled compounds have been calculated by using its HOMO and LUMO energy values. These parameters of the titled compound were obtained by using the following equations. By using Koopman's theorem for closed-shell molecules, the chemical hardness of any molecule can be calculated by the following relation:

The chemical potential of a molecule is calculated by:

The softness of a molecule is calculated by:

Electronegativity of the molecule is calculated by:

Electrophilic index of the molecule is calculated by:

Where A=-E HOMO is the ionization potential and I=-E LUMO is the electron affinity of the molecule. The calculated values such as EHOMO, ELUMO, ΔEgap, A, I, η, µ, S, χ and ω of benzo and anthraquinodimethane derivatives 1-4 calculated by B3LYP/6-31G(d,p) method are given in Table 5.

Figure 3. HOMO-LUMO structure with the energy level diagram of compound 1.

As presented in Table 5, the compound which have the lowest energetic gap is the compound 1 (∆Egap=2.589 eV). This lower gap allows it to be the softest molecule. The compound that have the highest energy gap is the compound 4 (∆Egap=3.489 eV). The compound that has the highest HOMO energy is the compound 1 (EHOMO=-4.191 eV). This higher energy allows it to be the best electron donor. The compound that has the lowest LUMO energy is the compound 1 (ELUMO=-1.602 eV) which signifies that it can be the best electron acceptor. The two properties like I (potential ionization) and A (affinity) are so important, the determination of these two properties allow us to calculate the absolute electronegativity (χ) and the absolute hardness (η). These two parameters are related to the one-electron orbital energies of the HOMO and LUMO respectively. Compound 1 has lowest value of the potential ionization (I=4.191 eV), so that will be the better electron donor. Compound 1 has the largest value of the affinity (A=1.602 eV), so it is the better electron acceptor. The chemical reactivity varies with the structural of molecules. Chemical hardness (softness) value of compound 1 (η=1.295 eV, S=0.658 eV) is lesser (greater) among all the molecules. Thus, compound 1 is found to be more reactive than all the compounds. Compound 4 possesses higher electronegativity value (χ=3.061 eV) than all compounds so; it is the best electron acceptor. The value of ω for compound 1 (ω=3.240 eV) indicates that it is the stronger electrophiles than all compounds. Compound 1 has the smaller frontier orbital gap so, it is more polarizable and is associated with a high chemical reactivity, low kinetic stability and is also termed as soft molecule.

Local reactivity descriptors

Fukui function is one of the widely used local density functional descriptors to model chemical reactivity and selectivity. The Fukui function is a local reactivity descriptor that indicates the preferred regions where a chemical species will change its density when the number of electrons is modified. Therefore, it indicates the propensity of the electronic density to deform at a given position upon accepting of donating electrons.30 The Fukui function of the system defines the more reactive regions in a molecule, the reactivity indices are directly concerned with the selectivity of the molecule towards specific chemical events. Using Mulliken atomic charges of neutral, cation and anion state of present molecules, Fukui functions (f +k; f-k; f 0k) are calculated.31 Fukui functions are calculated using the following equations:

,

for nucleophilic attack,

,

for electrophilic attack,

,

for radical attack.

Where +, - and 0 signs show nucleophilic, electrophilic and radical attack, respectively. Fukui functions for selected atomic sites in benzo and anthraquinodimethane derivatives 1-4 have been listed in Tables 6 and 7.

Table 5: Quantum chemical descriptors of benzo and anthraquinodimethane derivatives 1-4.

Parameters Compound 1 Compound 2 Compound 3 Compound 4
EHOMO(eV) -4.191 -4.289 -4.447 -4.805
ELUMO(eV) -1.602 -1.520 -1.562 -1.316
ΔEgap(eV) 2.589 2.769 2.885 3.489
IE (eV) 4.191 4.289 4.447 4.805
A (eV) 1.602 1.520 1.562 1.316
μ (eV) -2.896 -0.760 -3.004 -3.061
χ (eV) 2.896 0.760 3.004 3.061
ƞ (eV) 1.295 -0.760 1.442 1.745
S (eV) 0.386 -0.658 0.347 0.287
ω (eV) 3.240 -0.380 3.129 2.685

Table 6: Order of the reactive sites on compounds 1 and 2.

Compound 1 Compound 2
Atom 4C 1C 4C 3C Atom 35C 38C 2C 5C
f + 0.122 0.097 0.033 0.033 f + 0.203 0.203 0.062 0.062
Atom 18C 19C 11C 12C Atom 7C 8C 3C 4C
f - 0.014 0.014 0.014 0.014 f - 0.174 0.174 0.080 0.080
Atom 4C 3C 18C 19C Atom 18C 24C 25C 17C
f 0 0.020 0.020 0.016 0.016 f 0 -0.008 -0.008 -0.008 -0.008

Table 7: Order of the reactive sites on compounds 3 and 4.

Compound 3 Compound 4
Atom 38C 35C 5C 2C Atom 4C 1C 7C 8C
f + 0.202 0.202 0.081 0.081 f + 0.122 0.097 0.031 0.031
Atom 7C 8C 1C 6C Atom 27C 35C 28C 34C
f - 0.168 0.168 0.104 0.104 f - 0.011 0.011 0.011 0.011
Atom 4C 3C 18C 24C Atom 27C 35C 28C 34C
f 0 -0.007 -0.007 -0.007 -0.007 f 0 0.011 0.011 0.011 0.011

From the Tables 6 and7, the parameters of local reactivity descriptors show that 4C is the more reactive site in compounds 1 and 4 and 35C, 38C are the more reactive sites in compounds 2 and 3 respectively for nucleophilic attacks. The more reactive sites in radical attacks are 18C, 27C, for compounds 2, 4 respectively and 4C for the both compounds 1 and 3. The more reactive sites for electrophilic attacks are 7C for compounds 2, 3 and 18C, 27C for compounds 1 and 4 respectively.

Natural bond orbital analysis (NBO)

The second order Fock matrix was carried out to evaluate the donor–acceptor interactions in the NBO analysis. The interaction result is a loss of occupancy from the localized NBO of the idealized Lewis structure into an empty non-Lewis orbital. For each donor (i), and acceptor (j), the stabilization energy E(2) associated with the delocalization i - j is estimated as

Natural bond orbital analysis provides an efficient method for studying intra and intermolecular bonding and interaction among bonds, and also provides a convenient basis for investigating charge transfer or conjugative interaction in molecular systems.32 Some electron donor orbital, acceptor orbital and the interacting stabilization energy resulted from the second-order micro disturbance theory are where q i is the donor orbital occupancy, are ε i and ε j diagonal elements and F(i, j) is the off diagonal NBO Fock matrix element reported.33-35 The larger the E(2) value, the more intensive is the interaction between electron donors and electron acceptors, i.e. the more donating tendency from electron donors to electron acceptors and the greater the extent of conjugation of the whole system.36 Delocalization of electron density between occupied Lewis-type (bond or lone pair) NBO orbitals and formally unoccupied (anti-bond or Rydgberg) non-Lewis NBO orbitals correspond to a stabilizing donor–acceptor interaction. NBO analysis has been performed on the melamine molecule at the DFT/B3LYP/6-31G(d,p) level in order to elucidate the delocalization of electron density within the molecules. The second-order perturbation theory analysis of Fock matrix in NBO basis of benzo and anthraquinodimethane derivatives 1-4 is given in Tables 8-11.

The intra molecular interaction for the title compounds is formed by the orbital overlap between: π(C7-C8) and π*(C11-C12) for compound 1, π(C13-C14) and π*(C15-C16) for compound 2, π(C15-C16) and π*(C17-C18) for compound 3 and π(C23-C24) and π*(C27-C28) for compound 4 respectively, which result into intermolecular charge transfer (ICT) causing stabilization of the system. The intra molecular hyper conjugative interactions of π(C7-C8) to π*(C11-C12) for compound 1, π(C13-C14) to π*(C15-C16) for compound 2, π(C15-C16) to π*(C17-C18) for compound 3 and π(C23-C24) to π*(C27-C28) for compound 4 lead to highest stabilization of 21.16, 20.00, 21.07 and 20.97 kJ mol-1 respectively. In case of LP (2) S27orbital to the π*(C11-C12) for compound 1, LP(2) S33 orbital to π*(C17-C18) for compound 2, LP (2) S33 orbital to π*(C17-C18) for compound 3, LP(2) S43 orbital to π*(C27-C28) for compound 4 respectively, show the stabilization energy of 19.48, 19.68, 19.60 and 19.08 kJ mol-1 respectively.

Nonlinear optical properties (NLO)

Non-linear optical (NLO) materials play a major role in nonlinear optics and in particular they have a great impact on information technology and industrial applications. The first static hyperpolarizability (β) calculation was performed on the optimized geometry at B3LYP/6-31G(d,p). The first static hyperpolarizability (β0) is a third rank tensor that can be described by a 3 × 3 × 3 matrix. The 27 components of the 3D matrix can be reduced to 10 components due to the Kleinman symmetry.37 The components of µ, α, β are defined as the coefficients in the Taylor series expansion of the energy in the external electric field. When the external electric field is weak and homogeneous, this expansion of the energy in the external electric field is weak and homogeneous, this expansion becomes:

where, E0 is the energy of the unperturbed molecules, Ea is the field at the origin, µa is component of the dipole moment and αab, βabc, γabcd are the polarizability, first hyperpolarizability and second hyperpolarizability tensors, respectively. Total static dipole moment (µ0), mean polarizability (|α0|), anisotropy of polarizability (Δα) and first hyperpolarizability (β0), using x, y, z components are defined as.

Large value of particular component of the polarizability and hyperpolarizability indicate a substantial delocalization of charge in these directions. The total molecular dipole moment (µ), mean polarizability (α0) and anisotropy polarizability (Δα) and first hyperpolarizability (βtotal) of benzo and anthraquinodimethane derivatives 1-4 are computed and are depicted in Table 12.

Table 8: Second order perturbation theory analysis of Fock matrix on NBO of compound 1.

Donor(i) ED/e Acceptor(j ED/e E(2) Kcal/mol E(j)-E(i) a.u F(i.j) a.u
π(C7-C8) 1.67808 π*(C11-C12) 0.47705 21.16 0.25 0.068
π(C9-C10) 1.67808 π*(C11-C12) 0.47705 21.16 0.25 0.068
π(C17-C22) 1.67808 π*(C18-C19) 0.47705 21.16 0.25 0.068
π(C20-C21) 1.67808 π*(C18-C19) 0.47705 21.16 0.25 0.068
π(C7-C8) 1.67808 π*(C9-C10) 0.33806 19.98 0.28 0.067
π(C9-C10) 1.67808 π*(C7-C8) 0.33806 19.98 0.28 0.067
π(C17-C22) 1.67808 π*(C20-C21) 0.33806 19.98 0.28 0.067
π(C20-C21) 1.67808 π*(C17-C22) 0.33806 19.98 0.28 0.067
LP (2) S27 1.75911 π*(C11-C12) 0.47705 19.48 0.25 0.066
LP (2) S28 1.75911 π*(C11-C12) 0.47705 19.48 0.25 0.066
LP (2) S30 1.75911 π*(C18-C19) 0.47705 19.48 0.25 0.066
LP (2) S31 1.75911 π*(C18-C19) 0.47705 19.48 0.25 0.066
π(C11-C12) 1.67346 π*(C7-C8) 0.33806 17.78 0.31 0.066
π(C11-C12) 1.67346 π*(C9-C10) 0.33806 17.78 0.31 0.066
π(C18-C19) 1.67346 π*(C17-C22) 0.33806 17.78 0.31 0.066
π(C18-C19) 1.67346 π*(C20-C21) 0.33806 17.78 0.31 0.066
LP (2) S27 1.75911 π*(C3-C29) 0.40607 17.73 0.27 0.065
LP (2) S28 1.75911 π*(C3-C29) 0.40607 17.73 0.27 0.065
LP (2) S30 1.75911 π*(C4-C32) 0.40607 17.73 0.27 0.065
LP (2) S31 1.75911 π*(C4-C32) 0.40607 17.73 0.27 0.065

Table 9: Second order perturbation theory analysis of Fock matrix on NBO of compound 2.

Donor(i) ED/e ED/e Acceptor E(2) Kcal/mol E(j)-E(i) a.u F(i.j) a.u
π(C13-C14) 1.68011 π*(C15-C16) 0.33565 20.00 0.28 0.067
π(C23-C28) 1.68011 π*(C26-C27) 0.33565 20.00 0.28 0.067
π(C15-C16) 1.68038 π*(C13-C14) 0.33664 19.81 0.28 0.067
π(C26-C27) 1.68038 π*(C23-C28) 0.33664 19.81 0.28 0.067
LP(2) S33 1.76656 π*(C17-C18) 0.47394 19.68 0.25 0.067
LP(2) S37 1.76656 π*(C24-C25) 0.47394 19.68 0.25 0.067
π(C1-C2) 1.67557 π*(C5-C6) 0.33092 19.51 0.29 0.067
π(C5-C6) 1.67557 π*(C1-C2) 0.33092 19.51 0.29 0.067
π(C3-C4) 1.59383 π*(C1-C2) 0.33092 19.29 0.28 0.067
π(C3-C4) 1.59383 π*(C5-C6) 0.33092 19.29 0.28 0.067
π(C1-C2) 1.67557 π*(C3-C4) 0.43377 18.88 0.28 0.067
π(C5-C6) 1.67557 π*(C3-C4) 0.43377 18.88 0.28 0.067
σ(C9-H39) 1.97289 σ*(C7-C10) 0.02432 5.40 1.03 0.067
σ(C10-H40) 1.97289 σ*(C8-C9) 0.02432 5.40 1.03 0.067
σ(S33-C35) 1.97674 σ*(C3-C7) 0.03093 4.86 1.14 0.067
σ(S37-C38) 1.97674 σ*(C4-C8) 0.03093 4.86 1.14 0.067
σ(C7-C35) 1.98151 σ*(C3-C7) 0.03093 4.53 1.24 0.067
σ(C8-C38) 1.98151 σ*(C4-C8) 0.03093 4.53 1.24 0.067
σ(C17-C18) 1.97575 σ*(C16-C17) 0.02205 4.41 1.29 0.067
σ(C24-C25) 1.67393 σ*(C25-C26) 0.02205 4.41 1.29 0.067

Table 10: Second order perturbation theory analysis of Fock matrix on NBO of compound 3.

Donor(i) ED/e Acceptor(j) ED/e E(2) Kcal/mol E(j)-E(i) a.u F(i.j) a.u
π(C15-C16) 1.68001 π*(C17-C18) 0.47396 21.07 0.25 0.068
π(C26-C27) 1.68001 π*(C24-C25) 0.47396 21.07 0.25 0.068
π(C13-C14) 1.67940 π*(C17-C18) 0.47396 20.97 0.25 0.068
π(C23-C28) 1.67940 π*(C24-C25) 0.47396 20.97 0.25 0.068
π(C13-C14) 1.67940 π*(C15-C16) 0.33428 20.03 0.28 0.067
π(C23-C28) 1.67940 π*(C26 -C27) 0.33428 20.03 0.28 0.067
π(C15-C16) 1.68001 π*(C13-C14) 0.33490 19.80 0.28 0.067
π(C26-C27) 1.68001 π*(C23-C28) 0.33490 19.80 0.28 0.067
LP (2) S33 1.76441 π*(C17-C18) 0.47396 19.60 0.25 0.066
LP (2) S37 1.76441 π*(C24-C25) 0.47396 19.60 0.25 0.066
LP (2) S34 1.75185 π*(C17-C18) 0.47396 19.29 0.25 0.066
LP (2) S36 1.75185 π*(C24-C25) 0.47396 19.29 0.25 0.066
LP (2) S34 1.75185 π*(C7-C35) 0.37794 18.41 0.27 0.065
LP (2) S36 1.75185 π*(C8-C38) 0.37794 18.41 0.27 0.065
π(C17-C18) 1.67498 π*(C13-C14) 0.33490 17.78 0.31 0.066
π(C24-C25) 1.67498 π*(C23-C28) 0.33490 17.78 0.31 0.066
π(C1-C6) 1.51959 π*(C2-C3) 0.30667 17.64 0.27 0.065
π(C1-C6) 1.51959 π*(C4-C5) 0.30667 17.64 0.27 0.065
π(C17-C18) 1.67498 π*(C15-C16) 0.33428 17.59 0.31 0.066
π(C24-C25) 1.67498 π*(C26-C27) 0.33428 17.59 0.31 0.066

Table 11: Second order perturbation theory analysis of Fock matrix on NBO of compound 4.

Donor(i) ED/e Acceptor(j) ED/e E(2) Kcal/mol E(j)-E(i) a.u F(i.j) a.u
π(C23-C24) 1.67932 π*(C27-C28) 0.47248 20.97 0.25 0.068
π(C25-C26) 1.67932 π*(C27-C28) 0.47248 20.97 0.25 0.068
π(C33-C38) 1.67932 π*(C34-C35) 0.47248 20.97 0.25 0.068
π(C36-C37) 1.67932 π*(C34-C35) 0.47248 20.97 0.25 0.068
π(C23-C24) 1.67932 π*(C25-C26) 0.33811 19.94 0.28 0.067
π(C25-C26) 1.67932 π*(C23-C24) 0.33811 19.94 0.28 0.067
π(C33-C38) 1.67932 π*(C36-C37) 0.33811 19.94 0.28 0.067
π(C36-C37) 1.67932 π*(C33-C38) 0.33811 19.94 0.28 0.067
LP(2) S43 1.77196 π*(C27-C28) 0.47248 19.08 0.25 0.066
LP(2) S44 1.77196 π*(C27-C28) 0.47248 19.08 0.25 0.066
LP(2) S46 1.77196 π*(C34-C35) 0.47248 19.08 0.25 0.066
LP(2) S47 1.77196 π*(C34-C35) 0.47248 19.08 0.25 0.066
LP(2) S43 1.77196 π*(C7-C45) 0.30275 17.88 0.28 0.065
LP(2) S44 1.77196 π*(C7-C45) 0.30275 17.88 0.28 0.065
LP(2) S46 1.77196 π*(C8-C48) 0.30275 17.88 0.28 0.065
LP(2) S47 1.77196 π*(C8-C48) 0.30275 17.88 0.28 0.065
π(C27-C28) 1.67363 π*(C23-C24) 0.33811 17.86 0.30 0.066
π(C27-C28) 1.67363 π*(C25-C26) 0.33811 17.86 0.30 0.066
π(C34-C35) 1.67363 π*(C33-C38) 0.33811 17.86 0.30 0.066
π(C34-C35) 1.67363 π*(C36-C37) 0.33811 17.86 0.30 0.066

Table 12: The dipole moments µ (D), polarizability α, the average polarizability α (esu), the anisotropy of the polarizability Δα (esu), and the first hyperpolarizability β (esu) of benzo and anthraquinodimethane derivatives 1-4 calculated by B3LYP/6-31G(d,p) method.

Parameters Compound 1 Compound 2 Compound 3 Compound 4
βxxx 0.0001 0.0032 0.0022 0.0098
Βyyy 0.0000 9.0086 7.9717 49.1610
Βzzz -0.0010 0.0001 0.0001 0.0135
Βxyy 0.0000 0.0008 -62.3512 -0.0038
Βxxy -0.0001 -53.1625 -62.3512 134.6598
Βxxz 0.0180 -0.0115 -0.0086 -0.0258
Βxzz 0.0000 -0.0014 -0.0012 0.0015
Βyzz 0.0000 9.6934 1.4569 -16.0974
Βyyz 0.0010 0.0004 0.0002 -0.0203
Βxyz 0.0001 0.2353 -10.8202 0.0019
Βtot(esu)x10-33 0.0180 34.4613 54.0172 167.7234
µx 0.0000 0.0001 0.0000 0.0001
µy 0.0000 0.4567 -0.5289 1.7220
µz 0.0003 -0.0001 -0.0001 -0.0003
µtot(D) 0.0003 0.4567 0.5289 1.7220
αxx -114.1058 -151.1828 33.5363 -186.3754
αyy -152.6176 -180.2313 -1.8893 -199.9477
αzz -174.7878 -210.0422 -31.6470 -192.5924
αxy 0.0000 0.0003 0.0001 0.0001
αxz -0.0006 2.4498 1.4899 -0.0006
αyz 0.0000 -0.0002 0.0000 0.0021
α(esu)x10-24 53.1835 51.1515 56.5804 11.7677
∆α(esu)x10-24 7.8818 7.5806 8.3852 1.7440

Since the values of the polarizabilities (∆α) and the hyperpolarizabilities (βtot) of the GAUSSIAN 09 output are obtained in atomic units (a.u.), the calculated values have been converted into electrostatic units (e.s.u.) (for α; 1 a.u=0.1482 x 10-24 e.s.u., for β; 1 a.u=8.6393 x 10-33 e.s.u.). The calculated values of dipole moment (µ) for the title compounds were found to be 0.0003, 0.4567, 0.5289 and 1.7220 D respectively, which are approximately one times than to the value for urea (µ=1.3732 D). Urea is one of the prototypical molecules used in the study of the NLO properties of molecular systems. Therefore, it has been used frequently as a threshold value for comparative purposes. The calculated values of polarizability are 53.1835 x 10-24, 51.1515 x 10-24, 56.5804 x 10-24 and 11.7677 x 10-24 esu respectively; the values of anisotropy of the polarizability are 7.8818, 7.5806, 8.3852 and 1.7440 esu, respectively. The magnitude of the molecular hyperpolarizability (β) is one of important key factors in a NLO system. The DFT/6-31G(d,p) calculated first hyperpolarizability value (β) of benzo and anthraquinodimethane derivatives molecules are equal to 0.0180 x 10-33, 34.4613 x 10-33, 54.0172 x 10-33 and 167.7234 x 10-33 esu. The first hyperpolarizability of title molecules is approximately 0.00, 0.10, 0.16 and 0.48 times than those of urea (β of urea is 343.272 x10-33 esu obtained by B3LYP/6-31G (d,p) method). The above results show that benzo and anthraquinodimethane derivatives 1-4 might have not the NLO applications.

Conclusions

The results of this work are complemented and discussed within the scope of quantum chemical calculations with DFT calculations. The MEP map shows that the negative potential sites are on conjugated aromatic rings as well as the positive potential sites are around the aromatic hydrogen atoms. These sites may provide information about the possible reaction regions for the title structures. The value of the energy separation between the HOMO and LUMO of compound 1 is very small 2.589 eV compared to other compounds and this energy gap gives significant information about the reactivity of studied compounds. So we conclude that compound 1 is softest, best electron donor and more reactive than all compounds. The calculated first order hyperpolarizability was found much lesser than reported in literature for urea.

Acknowledgements

This work was generously supported by the (General Directorate for Scientific Research and Technological Development, DGRS-DT) and Algerian Ministry of Scientific Research.

Funding: No funding sources

Conflict of interest: None declared

References

  1. Williams JM, Ferraro JR, Thorn RJ, Carlson KD, Geiser U, Wang HH, et al. Prentice Hall, Organic Superconducyors (including Fullerenes). New Jersey. 1992;Chapters 2-4:66.
  2. Williams JM, Beno MA, Wang HH, Leung PCW, Emge TJ, Geiser U, et al. Organic superconductors: structural aspects and design of new materials. Acc Chem Res. 1985;18:261-7.
  3. Bryce MR. Recent progress on conducting organic charge-transfer salts. Chem Soc Rev. 1991;20:355-90.
  4. Segura JL, Martin N. New Concepts in Tetrathiafulvalene Chemistry. Angew Chem Int Ed Engl. 2001;40:1372.
  5. Gompper R, Wagner HU. Donor-acceptor-substituierte cyclische π-Elektronensysteme-Prüfsteine für Theorien und Bausteine für neue Materialien. Angew Chem. 1988;100:1492-511.
  6. Wolf JJ, Wortmann R. Organic Materials for Second-Order Non-Linear Optics. Adv Phys Org Chem. 1999;32:121-217.
  7. Barlow S, Marder SR. Functional Organic Materials: Syntheses, Strategies and Applications. Wiley-VCH, Weinheim; 2007: 393-437.
  8. Tykwinski RR, Gubler U, Martin RE, Diederich F, Bosshard C, Günter P. Structure-Property Relationships in Third-Order Nonlinear Optical Chromophores. J Phys Chem. 1998;102B:4451-65.
  9. May JC, Biaggio I, Bures F, Diederich F. Extended conjugation and donor-acceptor substitution to improve the third-order optical nonlinearity of small molecules. Appl Phys Lett. 2007;90:251106/1-251106/3.
  10. Gisselbrecht JP, Moonen NNP, Boudon C, Nielsen MB, Diederich F, Gross M. Redox Properties of Linear and Cyclic Scaffolds Based on Di-and Tetraethynylethene. Eur J Org Chem. 2004:2959-72.
  11. Lee SY, Boo BH. Molecular structure and vibrational spectra of 9-Fluorenone density functional theory study. Bull Korean Chem Soc. 1996;17:760-4.
  12. Devlin FJ, Finley JW, Stephens PJ, Frish MJ. Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields: a comparison of local, nonlocal, and hybrid density functionals. J Phys Chem. 1995;99:16883-902.
  13. Chis V. Molecular and vibrational structure of 2,4-dinitrophenol: FT-IR, FT-Raman and quantum chemical calculations. J Chem Phys. 2004;300:1-11.
  14. Asensio A, Kobko N, Dannenberg JJ. Cooperative Hydrogen-Bonding in Adenine-Thymine and Guanine-Cytosine Base Pairs. Density Functional Theory and Møller-Plesset Molecular Orbital Study. J Phys Chem A. 2003;107:6441-43.
  15. Briffautleguiner F, Dao NQ, Jouan M, Plaza P. Champ de force de valence du 3-Méthyl 4-nitro pyridine N-oxyde (POM). Spectrochim Acta A. 1994;50:2091-100.
  16. Liu XJ, Xu XJ, Zhang CW. Hyperpolarizability calculation and kinetic effect of impurities on LVP. Spectrochim Acta A. 2015;137:378-82.
  17. Abd El-Wareth A, Sarhan O. Synthesis and applications of tetrathiafulvalenes and ferrocene-tetrathiafulvalenes and related compounds. Tetrahedron. 2005;61:3889-932.
  18. Frisch MJ, Trucks GW, Schlegel HB, Scuseria GE. Gaussian 09, Revision B.01,Gaussian, Inc., Wallingford, CT. 2010.
  19. Schlegel HB. Optimization of equilibrium geometries and transition structures. J Comput Chem. 1982;3:214-8.
  20. Scrocco E, Tomasi J. Electronic Molecular Structure, Reactivity and Intermolecular Forces: An Euristic Interpretation by Means of Electrostatic Molecular Potentials. Adv Quantum Chem. 1978;103:115-93.
  21. Luque FJ, Lopez JM, Orozco M. Perspective on "Electrostatic interactions of a solute with a continuum. A direct utilization of ab initio molecular potentials for the prevision of solvent effects". Theor Chem Acc. 2000;103:343-5.
  22. Politzer P, Murray JS, in: D.L. Beve ridge, R. Lavery, (Eds.), Theoretical Biochemistry and Molecular Biophysics, Springer, Berlin; 1991.
  23. Scrocco E, Tomasi J. The electrostatic molecular potential as a tool for the interpretation of molecular properties. Top Curr Chem. 1973;42:95-170.
  24. Choudhary N, Bee S, Gupta A, Tandon P. Comparative vibrational spectroscopic studies, HOMO–LUMO and NBO analysis of N-(phenyl)-2,2-dichloroacetamide, N-(2-chloro phenyl)-2,2-dichloroacetamide and N-(4-chloro phenyl)-2,2-dichloroacetamide based on density functional theory. Comp Theor Chem. 2013;1016:8-21.
  25. Sinha L, Prasad O, Narayan V, Shukla SR. Raman, FT-IR spectroscopic analysis and first-order hyperpolarisability of 3-benzoyl-5-chlorouracil by first principles. J Mol Simul. 2011;37:153-63.
  26. Lewis DFV, Loannides C, Parke DV. Interaction of a series of nitriles with the alcohol-inducible isoform of P450: Computer analysis of structure-activity relationships. Xenobiotica. 1994;24:401-8.
  27. Kosar B, Albayrak C. Spectroscopic investigations and quantum chemical computational study of (E)-4-methoxy-2-[(p-tolylimino)methyl]phenol. Spectrochim Acta. 2011;78:160-7.
  28. Gece G. The use of quantum chemical methods in corrosion inhibitor studies. Corros Sci. 2008;50:2981-92.
  29. Fukui K. Role of frontier orbitals in chemical reactions. Science. 1982;218:747-54.
  30. Fukui K, Yonezzawa T, Shingu H. A molecular orbital theory of reactivity in aromatic hydrocarbons. J Chem Phys. 1952;20:722-5.
  31. Ayers PW, Parr RG. Variational principles for describing chemical reactions:  the fukui function and chemical hardness revisited. J Am Chem Soc. 2000;122:2010-8.
  32. Subhashandrabose S, Akhil R, Krishnan R, Saleem H, Parameswari R, SundaraganesaN, Thanikachalam V, Manikandan G. Vibrational spectroscopic study and NBO analysis on bis(4-amino-5-mercapto-1,2,4-triazol-3-yl) methane using DFT method. Spectrochim Acta A. 2010;77:877-84.
  33. Liu JN, Chen ZR, Yuan SF, Zhejiang J. Uni Sci B. 2005;6:584-9.
  34. James C, Amalraj A, Regunathan A, Jayakumar VS, Joe IH. Structural conformation and vibrational spectroscopic studies of 2,6-bis(p-N,N-dimethyl benzylidene) cyclohexanone using density functional theory. J Raman Spectrosc. 2006;37:1381-92.
  35. Krishanan AR, Saleem H, Subhashandrabose S, Sundaraganesan N, Sebastian S. Molecular structure, vibrational spectroscopic (FT-IR, FT-Raman), UV and NBO analysis of 2-chlorobenzonitrile by density functional method. Spetrochim Acta A. 2011;78:582-9.
  36. Sebastian S, Sundaraganesan N. The spectroscopic (FT-IR, FT-IR gas phase, FT-Raman and UV) and NBO analysis of 4-hydroxypiperidine by density functional method. Specrochim Acta A. 2010;75:941-52.
  37. Kleinmann DA. Nonlinear dielectric polarization in optical media. Phys Rev. 1962;126:1977.

Refbacks

  • There are currently no refbacks.




Copyright (c) 2018 Pharmaceutical and Biological Evaluations

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.



Creative Commons License

 

© Copyright 2018 - Pharmaceutical and Biological Evaluations