Structural and Theoretical Investigation of N ’-[ ( E )-( 4-Bromophenyl ) ( Phenyl ) Methylidene ]-4-Methyl benzene sulfonohydrazide Crystal Prepared by Slow Evaporation Method

1Research and Development Center, Bharathiar University, Coimbatore 641 046, Tamil Nadu, India. 2Department of Physics, K.S.Rangasamy College of Technology, Tiruchengode-637215, Tamil Nadu, India. 3Department of Energy Studies, Periyar University, Salem-636011, Tamil Nadu, India. 4Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020, Tamil Nadu, India. *Corresponding author E-mail: maadesphysics@gmail.com


INTROdUCTION
Benzophenone can be used as a photo initiator in UV-curing applications 1 such as inks, imaging, and clear coatings in the printing industry.Benzophenone prevents ultraviolet (UV) light from damaging scents and colors in products such as perfumes and soaps.This can also be added to plastic packaging as a UV blocker to prevent photo-degradation of the packaging polymers or its contents.Its use allows manufacturers to package the product in clear glass or plastic (such as a PETE water bottle).Without it, opaque or dark packaging would be required.Its derivatives have been investigated extensively for their biological activities such as anti-fungal and anti-inammatory [2][3][4][5][6][7] .
In present study, Molecular geometry, Optimized parameters, Atomic charges, Mulliken charges, HOMO (highest occupied molecular orbital) and LUMO (Lowest unoccupied molecular orbital) energies, Frontier orbital energy gap, Molecular electrostatic potential, properties are experimental and computed the performance of the computational methods for ab initio B3LYP STO-3gG basis set are compared.

Synthesis
The 4-Bromoobenzophenone (1 mmol) and tosylhydrazide (1mmol) were dissolved in ethanol (50 ml).The reaction mixture was heated under reflux for 3 hr and cooled gradually to room temperature 8 .The reaction mechanism is shown in Fig. 1.Crystals suitable for X-ray diffraction analysis were obtained by slow room temperature evaporation of the solution containing the compound.The as grown crystals of N-[(E)-(4-Bromophenyl)(phenyl)methylidene]-4methyl benzene sulfonohydrazide is depicted in Fig. 2.

Computational details
The quantum chemical calculation of N-[(E)-(4-Bromophenyl) (phenyl)methylidene]-4-methyl benzene sulfonohydrazide has been performed using the B3LYP STO-3gG level of basis set, using the Gaussian 09 Program.The optimized geometries corresponding to the minimum on the potential energy surface have been obtained by solving self-consistent field equation iteratively.The B3LYP STO-3gG level of basis set was used for HOMO-LUMO analysis, Electrostatic potential (MESP) properties were calculated by Gaussian 09 Program 9 .

Characterization techniques
Characterization: Single crystal X-ray intensity data of sucrose was collected at room temperature (T = 296 K) on a Bruker X8 KAPPA APEX-II CCD diffractometer equipped with graphite mono chromated Mo Ka radiation.Initial unit cell parameters were obtained from SMART V5.05 software for CCD detector system; Bruker Analytical X-ray Systems, Madison, WI, 1998.Data integration, correction for Lorentz polarization effects and final cell refinement were performed by SAINTPLUS, V5.00 Software for the CCD detector system; Bruker Analytical X-Ray System, Inc.: Madison, WI, 1998.An empirical absorption correction based on the multiple measurements of equivalent reflections was applied using SADABS, Program for absorption correction using SMART CCD based on the method of Blessing.Structure was obtained by a combination of the direct methods and difference Fourier syntheses and refined by full-matrix least-squares on F2 using the SHELXTL.4(a-c) and 5(a-c).The powder XRD pattern is shown in the Fig. 6.

Single
In order to find the most optimized geometric parameters (bond length, bond angle and dihedral angles), the energy calculation are carried out for N'-[(E)-(4-Bromophenyl) (phenyl)methylidene]-4methylbenzenesulfonohydrazide, using B3LYP STO-3gG basis set value is given in the Table (1-3).The hydrazones molecules are attracted considerable

Mulliken population analysis
The atomic charges in molecules are fundamental to chemistry.For instance, atomic   [10, 11].We have examined the Mulliken atomic charges in solution (Methanol) in Table 5.The Mulliken atomic charges calculated at the B3LYP STO-3gG.It is worthy to mention that C6, C7, and C17 atoms of N'-[(E)-(4-Bromophenyl)(phenyl)methylidene]-4-methyl benzene sulfonohydrazide molecules exhibit positive charge, while C1, C2, C3, C4, C5, C8, C9, C10, C11, C12, C13, C14, C15, C16, C18, C19, and C20 atoms exhibits negative charges, Oxygen O1 and O2 has a maximum negative charges -0.46224 and -0.47788 for this values B3LYP STO-3gG basis set.The maximum positive atomic charges (1.235288) are obtained for S1 which is sulfonate present in the functional group SO 3 -.The positive atomic charges are observed (0.027547) for bromine atoms.The magnitude of hydrogen atomic charges is hydrogen atomic charges are found to be only positive and negative charges obtain, this listed given in the Table 5 for this B3LYP STO-3gG basis sets for the N'-[(E)-(4-Bromophenyl)(phenyl)methylidene]-4methyl benzene sulfonohydrazide molecules.The atomic charges plotted B3LYP STO-3gG basis set has been shown in Fig. 7.The nitrogen atoms presence of negative charges are N1 (-0.15703) and N2 (-0.45769) atoms.The above result shows that the natural atomic charges are more sensitive to the

HOMO-LUMO analysis
A deeper understand of chemical reactivity can be gained by this electronic absorption corresponds to the transition from the ground state to the first excited state and it is mainly described by one electron excitation from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO) 12,13 .HOMO represents the ability to donate an electron and LUMO represent the ability to obtain an electron.The HOMO is delocalized over the Bromine substituted two benzene ring and bridge over the N-NH group.The LUMO is located on the Bromo benzophenone and tosylhydrazide group.Consequently, the HOMO-LUMO transition implies an electron density transfer from, the more aromatic part of the p-conjucated system including the electron donor group to its more quinonid side and mainly to the electron with drawing end the frontier molecular orbital's of The calculated Self Consistent Field (SCF) energy of N'-[(E)-(4-Bromophenyl)(phenyl) methylidene]-4-methylbenzenesulfonohydrazide is -3958.29016076a.u. at B3LYP STO-3gG .The HOMO and LUMO energy gap explains the fact that eventual charge transfer interaction is taking place within the molecules.

HOMO-LUMO energy gap and related molecular properties
The HOMO, LUMO and HOMO-LUMO energy gap of N'-[(E)-(4-Bromophenyl)(phenyl) methylidene]-4-methyl benzene sulfonohydrazide molecules in the B3LYP STO-3gG basis set has been calculated.The HOMO-LUMO energy gap reveals that the energy gap reflects the chemical activity of the molecule.Associated within the framework of SCF MO theory the ionization energy and electron affinity can be expressed through HOMO and LUMO orbital energies as I = -E HOMO and A= -E LUMO .The hardness corresponds to the gap between the HOMO and LUMO orbital energies.The larger the HOMO-LUMO energy gaps the harder the molecules 14 .The global hardness, η =1/2(E LUMO -E HOMO ).The hardness has been associated with the stability of chemical system.The electron affinity can be used in combination with ionization energy to give electronic chemical potential, m=1/2(E HOMO + E LUMO ).The global electrophilicity index, ω = m 2 /2η is also calculated and listed in Table 4.

Molecular electrostatic potential (MEP)
The 3D plots of molecular electrostatic potential (MEP) of N'-[(E)-(4-Bromophenyl)(phenyl) The MEP is a useful property to study reactivity given that an approaching electrophile will be attracted to negative region (where the electron distribution effect is dominant).In the majority of the MEPs, while the maximum negative region which preferred site of for electrophilic attack indication as red colour, the maximum positive region which preferred site for nucleophilic attack symptoms as blue colour.
The importance of MEP lies in the fact that it simultaneous displays molecular size, shape as well as positive, negative and neutral electrostatic potential regions in terms of colour grading (Fig. 9) and is very useful in research of molecular structure with its physiochemical property relationship 15,16 .The resulting surface simultaneously displays molecular size and shape and electrostatic potential value.
The different values of the electrostatic potential at the surface are represented by different colours.The potential increases in the order red < orange < yellow < green< blue.The colour code of these maps is the range between the HOMO -1.437 a.u.
crystal x-ray diffraction N -[ ( E ) -( 4 -B r o m o p h e n y l ) ( p h e n y l ) methylidene]-4-methylbenzenesulfonohydrazide optimized geometric crystal structure is shown in the Fig. 3, belongs to the noncentro symmetric monoclinic space group P2 1 /c and the cell dimensions are a=8.4480Å,b=19.7198Å, c=12.9679Å; a=g=90 o and b=120.046;and V=1870.06Å 3 .The packing diagram in N-[(E)-(4-Bromophenyl)(phenyl)methylidene]-4-methyl benzene sulfonohydrazide molecule and crystal structure view along the (a) a-axis (b) b-axis, and (c) c-axis is presented in Fig.

Fig. 10 :
Fig. 10: The total electron density surface mapped with electrostatic potentialN'-[(E)-(4-Bromophenyl)(phenyl)methylidene]-4-methylbenzenesulfonohydrazide molecules methylidene]-4-methyl benzene sulfonohydrazide molecule is illustrated in Fig. 9.The MEP is a plot of electrostatic potential mapped onto the constant electron density surface.The MEP surface superimposed on top of the total energy density.The MEP is a useful property to study reactivity given that an approaching electrophile will be attracted to negative region (where the electron distribution effect is dominant).In the majority of the MEPs, while the maximum negative region which preferred site of for electrophilic attack indication as red colour, the maximum positive region which preferred site for nucleophilic attack symptoms as blue colour.The importance of MEP lies in the fact that it simultaneous displays molecular size, shape as well as positive, negative and neutral electrostatic potential regions in terms of colour grading (Fig.9) and is very useful in research of molecular structure with its physiochemical property relationship15,16 .The resulting surface simultaneously displays molecular size and shape and electrostatic potential value.
(Deepest red) to 1.437 a.u.(Deepest blue) and LUMO is -1.521 a.u.(Deepest red) to 1.521 a.u in N'-[(E)-(4-Bromophenyl)(phenyl) methylidene]-4-methyl benzene sulfonohydrazide molecules.Whereas blue colour indicates the strongest attraction and red colour indicates the strongest repulsion.The regions of negative V(r) are usually associated with the lone pair of electro native atoms.The contour map of electrostatic potential of the N'-[(E)-(4-Bromophenyl)(phenyl)methylidene]-4-methyl benzene sulfonohydrazide molecule has been constructed by the B3LYP STO-3gG basis set is shown in Fig. 10also confirms the different negative (-4.700 a.u.) and positive (-4.700 a.u.) potential sites of the molecules in accordance with the total electron density surface.