Synthesis, Characterization and Theoretical Investigation of Innovative Charge-transfer Complexes Derived from the N-phenyl 3,4-selenadiazo Benzophenone Imine

: In the current study, a direct method was used to create a new series of charge-transfer complexes of chemicals. In a good yield, new charge-transfer complexes were produced when different quinones reacted with acetonitrile as solvent in a 1:1 mole ratio with N-phenyl-3,4-selenadiazo benzophenone imine. By using analysis techniques like UV, IR, and 1 H, 13 C-NMR, every substance was recognized. The analysis's results matched the chemical structures proposed for the synthesized substances. Functional theory of density (DFT) has been used to analyze the molecular structure of the produced Charge-Transfer Complexes, and the energy gap, HOMO surfaces, and LUMO surfaces have all been created throughout the geometry optimization process utilizing the base set of 3–21G geometrical structures. The molecular geometry and contours for compounds with charge-transfer complexes have been evaluated during the process of geometrical optimization. By investigating the interactions between donor and acceptor, we have also been contrasting the energies (HOMO energies) of the chemicals in charge-transfer complexes. For molecules containing charge-transfer complexes, the lower case


Introduction:
Organic complexes of charge-transfer consist of two systems formed by a pair of electrons with a specified stoichiometry-an electron donor and an electron acceptor unit.For many years, chargetransfer complexes have been thoroughly studied in an attempt to develop standards for creating materials with high room-temperature mobility or superconductivity 1 .However, in recent years, attention has also been given to the creation of more technologically advanced applications utilizing such charge-transfer complexes [2][3][4] .As an example, ferroelectrics 5 , photoconductors 6,7 , light detectors 8 , strain sensors 9 , thermoelectric 10 , transistors of organic field-effect (OFETs), where CT complexes can function as organic metals 11,12 or organic semiconductors 13,14 .Organoselenium compounds have long been demonstrated to be particularly significant chemicals from a practical standpoint, in addition to being useful intermediate products in organic synthesis and realistic models for exploring fundamental difficulties of theoretical chemistry 15- 18 .Organoselenium compounds' unusual properties make them ideal as synthons because seleniumcontaining fragments can be easily incorporated into organic compounds and selenium atoms can be eliminated through appropriate processes, such as oxidation, which results in the formation of a double bond through synelimination of selenium oxide 19 .The majority of the reactions used to synthesis organo compounds of selenadiazole are known to be based on the interaction between organo diamine and selenium dioxide [20][21][22] .This study's objective is to synthesize new charge-transfer complexes by reacting five types of quinones (p-benzoquinone, panthraquinone, Tetrachloro benzoquinone (TCBQ), 7, 7, 8, 8-Tetracyano quino dimethane, 1,4-

Preparing p-Anthraquino N-phenyl 3,4-
selenadiazo Benzophenone Imine (IV) An amount of (2 mmol) 0.725 g of N-phenyl 3,4selenadiazo benzophenone imine was dissolved in 30 ml of acetonitrile and mixed with (2 mmol) 0.416 g of anthraquinone dissolved in 30 ml of acetonitrile and heated using reflux in a water bath for 3 hours.The solution was cooled and evaporated by a rotary evaporator and washed with small amounts of acetonitrile to obtain pure and shiny light-yellow crystals precipitate with an 64% yield and an M.P (melting point) of 118-208 °C.Rf value=0.85(7:3) (Ethyl acetate\n-hexane).UV-visible spectra were recorded at 200-750 nm in solvent of DMSO, n-π* and π-π* are two different types of electronic transitions with ʎ max (215 nm, 230 nm,240 nm, 248 nm, 252 nm, 275 nm, 350 nm).FT-IR with KBr disk:

Preparing Tetrachloro Benzoquino N-phenyl
3,4-selenadiazo Benzophenone Imine(V) An amount of (2 mmol) 0.725 g of N-phenyl 3,4selenadiazo benzophenone imine was dissolved in 30 ml of acetonitrile and mixed with (2 mmol) 0.491 g of Tetrachloro benzoquinone dissolved in 30 mL of acetonitrile and heated using reflux in a water bath for 3 hours.The solution was cooled and evaporated by a rotary evaporator and washed with small amounts of acetonitrile to obtain a pure and shiny dark brown crystal crystals precipitate with an 71% yield and an M.P (melting point) of 170-230 °C.Rf value=0.88 (7:3) (Ethyl acetate\n-hexane).UVvisible spectra were recorded at (200-750) nm in solvent of DMSO, n-π* and π-π* are two different types of electronic transitions with ʎ max 215 nm, 237 nm, 240 nm, 248 nm, 285 nm, 350 nm.FT-IR with KBr disk: υ

Results and Discussion:
The current research included the synthesis of charge transfer complexes that were produced by N-phenyl 3,4-selenadiazo benzophenone imine 23 (prepared in the second step) by reacting N-phenyl 3,4-selenadiazo benzophenone imine 23                      UV-visible spectra were recorded at 200-750 nm in (DMSO) solvent, n-π* and π-π* are two different types of electronic transitions 24 , are provided, such as Figs 1-7, as shown in Table 1.ʎ max for prepared complex compounds with a wavelength range of 205-473 nm.The infrared (IR) spectra of all synthesized complexes showed common characteristic bands and specific regions other locations.The synthesized compounds suggested structures were verified by using the IR spectrum 25,26.They are provided in Figs.8-14 and Table 2. Ar.C-H appeared at 3051-3070 cm-1 for N-phenyl 3,4-selenadiazo benzophenone imine and charge transfer complexes derivatives, while Ar.(C=O) appeared at 1649-1795 cm -1 , Ar. C=N at 1579-1683 cm -1 , whereas aliphatic C≡N at 2222 cm - 1 , Ar. C=C at 1448-1591 cm -1 , Aliphatic C=C at 1433 cm -1 , Ar. C-Se-N at 3138-3356 cm -1 , Ar. O-H at 3500-3600 cm -1 , and Ar. at 550-800 cm -1 . 1 H-NMR spectra of the compounds (I-VII) showed all the peaks as expected with explanations.Figs 15-21 and Table 3 show DMSO spectra for each selected compound.

Computational Analysis
The charge-transfer complex compounds of N-phenyl 3,4-selenadiazo benzophenone imine under analysis were labeled as shown in Figs.24-43.It was determined how well the method described the compound's properties in the gas phase.The functional theory of density (DFT) at hybrid functional (B3LYP), the levels of functional computational its combine between Parr's, and Lee, Yang correlation with exchange Becke's, was used to analyze the electronic characteristics and geometric structures of these compounds by all quantum calculations 27,28 .Using the basis of the set of 3-21G and the Gaussian (G09W) software, this method described each atom 29 .Using estimated DFT-based descriptors, the compounds' reactivity and stability were assessed [30][31][32][33] through the mathematical relations as in the Eq.1, Eq.2, Eq.3 and Eq.Where the μ = (chemical potential), η = (chemical hardness), S = (chemical softness), and ω = (electrophilicity), while E = (the total electron energy), N = (number of electrons), and V(r→) is (the external potential) respectively.The above global quantities were calculated by using two variations approaches; the first is a difference in a finite approximation, this is based on the changes in total electronic energy that occurs after the neutral molecule whenever an electron is added or removed.The energies of (HOMO) and (LUMO) different for molecules serve as the foundation for Koopman's theory 30,33,34  The equilibrium geometries for all CT (charge-transfer) complex compounds in the gaseous phase were carefully tuned at level of the (DFT) 32 for theory using the functional of a (B3LYP,) in (G09W) and the basis standard established (3-21G) (see Figs. 24-43).The energies of (HOMO) Molecular Orbital High Occupied and (LUMO) Molecular Orbital Low Unoccupied are the states of electrons, defining certain regions where atomic and molecular orbitals combine linearly, leading to the existence of electrons with quantized energy.The relationship between the energy band gap (Eg) Eq.9, Eq.6.and the difference in (LUMO) and (HOMO) 35 .The property of the Eg is essential in solids because it makes material prediction possible, if it is an insulator, semiconductor, or conductor.It depicts the difference in energy between the higher full energy level and the lower level of virtual energy. 36.See Figs.(24-43) and Table4.

Electronegativity and Electrophilicity
The molecule's ability to take up electrons is measured by chemical electrophilicity, which is determined by chemical electrophilicity, which is dependent on chemical hardness and chemical potential, where hardness is resistance to deformation and change.On the other hand, electronegativity measures an atom's capacity to attract an electron density (a shared pair of electrons) towards itself.Calculating electrophilicity and electronegativity can be done using relationships in Eq.10, Eq.11. 22,30,31

Ionization Potential, and Electron Affinity
Measurement of the bond's strength is done via the ionization potential among an atom and an electron.It possesses the same amount of energy as what is needed to expel one electron from a neutral atom in the gas phase.When an atom takes an electron, energy is released, which is referred to as having a "electron affinity."It is the necessary energy to remove an electron from a negatively charged ion.This is consistent with Koopman's theory 28 , as seen in Eq.12, Eq.13 and Table 6.

HSAB Principle (Acid Base Hardness Softness)
When utilized as acids and bases in chemistry, this principle describes how atoms or molecules behave.First, it must be shown that soft and hard acids are acceptors, whereas hard and soft bases are donors.Eq.14, Eq.15.are used to show both hardness and softness [37][38][39] .
Chemical softness and hardness are indicated, respectively, by the symbols (σ) and (η).based on Table 6.

Conclusion:
The current work outlines simple and doable procedures for creating a variety of unique chargetransfer complex molecules.Compounds I, II, III, IV, V, VI, and VII were synthesized with a 64-80 percent yield rate. Results from the investigation of the FT-IR, 1 H-NMR, and UV-visible Spectrophotometer in the current study are consistent with those from earlier studies in these subjects.Verifying that the predicted structures for each of the synthesized molecules are accurate.Regarding the theoretic inquiry, it may be concluded that the DFT (density functional theory) to be used in the investigation is a reliable technique, as well as B3LYP functional is an appropriate and effective method function to analyze the electronic properties of these molecular structures.The testing results were consistent with the 3-21G's geometrical characteristics (d, p).The electronic properties for compounds of chargetransfer complex are investigated in this work utilizing the density functional theory (DFT) method, together with geometry optimization using the functionals of B3LYP.
Total energies in addition to geometric structures (donor and acceptor,) systems showed how extremely stable the structures are.Additionally, as compared to other systems, the donor-acceptor system has a higher reactivity and an average polarizability.As a result of the study's findings, we are now able to choose the kind of bridge that will work with acceptor and donor to determine the physical characteristics of the acceptor, bridge, and donor.

14 and 21 .
Scheme 3. Preparation of quino N-phenyl 3,4-selenadiazo Benzophenone Imine (compounds III, IV, V, VI, and VII) using acetonitrile as solvent and adding five types of different quinones (each quinone has a separate reaction) to obtain new charge transfer complexes compounds (III-VII).The transitions of n-π* typically experienced a significant shift in blue during synthesis complexes of charge-transfer.The responsible for the deviating of the electron cloud around it and for a change in the evolution of the charge-transfer complexes.The bands of absorption shifted to shorter wave lengths when quinones' electron donors decreased the π-π* and n-π* transitions, chromophore group conjugate effects, increasing the required energy for transitions of π-π* and n-π*.Are provided in Figs.1-7, as shown in Table1.

Figure 24 .
Figure 24.Molecular structure Ball and tube model of compound (I).

Figure 25 .
Figure 25.Molecular structure Ball and tube model of compound (II).

Figure 26 .
Figure 26.Molecular structure Ball and tube model of compound (III).

Figure 27 .
Figure 27.Molecular structure Ball and tube model of compound (IV).

Figure 28 .
Figure 28.Molecular structure Ball and tube model of compound (V).

Figure 29 .
Figure 29.Molecular structure Ball and tube model of compound (VI).

Figure 30 .
Figure 30.Molecular structure Ball and tube model of compound (VII).

Table 3 . The spectral 1 H-NMR data of synthesized compounds.
. Global quantities that are derivable from Eqs. 5 and 6 are approximated using finite differences.