This work is concerned with a combined approach to study the design of three transition metal complexes (platinum (II)/, copper (II)/ and nickel (II)) of 1-(E-(2, 4-dibromophenylimino) methyl) naphthalene-2-ol (HL) ligand, which were virtually designed in silico evaluation as efficient candidates for drug discovery applications. The mono deprotonated (L) ligand act as a bidentate coordinated to transition metal ions through the N and O donor atoms. The studied complexes have been physico-chemically characterized. The structure of the metal (II) complexes analysed through spectral data showed four coordinated tetrahedral complexes with 1:2 (metal: ligand) stoichiometry. The values of quantum yield and fluorescence intensity of metal (II) complexes were found to be more in comparison to HL. The preliminary tests were also conducted and reported in the theoretical biological activities. The photophysical and optical properties of the titled complexes was also incorporated in the study. Furthermore, the quantum computational methods are used for the calculation of linear polarizability, nonlinear optical polarizability, which shows the synthesized complexes as effective NLO materials. Frontier molecular orbitals, total density of state and partial density of state are also studied. Thus, we hope that the present study will provoke not only the interest of material chemists in materials designing but also incite the drug designing community within the medicinal chemistry.
Research Article
Spectroscopic characterization, virtual drug designing, quantum and optoelectronics properties of Schiff base metal (II) complexes
https://doi.org/10.21203/rs.3.rs-880545/v1
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Transition metal complexes
Quantum yield
Optoelectronic
Medicinal chemistry
Preliminary test
FMO
Table 1. Infrared characteristics bands frequencies (cm-1) of the HL ligand and its complexes.
Table 2. UV-Vis and photophysical data of the HL ligand and its complexes.
|
Compounds |
Absorbance band (nm) |
Emission (nm) |
Stoke shift |
Slope |
Quantum yield (%) |
Molar absorptivity (Ɛ, M-1 cm-1) |
||||
|
𝛌max |
n-π* |
π-π* |
CT |
𝛌ex |
𝛌em |
|||||
|
Bidentate ligand(HL) Pt-complex (1) Cu-complex(2) Ni-complex (3) Standard (Q. Sulphate) |
343 261 261 260 - |
- 278 266 272 - |
343 323 325 325 - |
- 412 420 415 - |
415 415 415 415 - |
445 480 470 460 - |
75 65 55 45 - |
1.428 1.928 1.637 1.446 2.438 |
1.231 2.643 2.532 2.478 0.50 |
4600 9600 13400 11200 - |
Table 3. The calculated values of polarizability, and third-order NLO polarizability <γ> (×10-36 esu) along with their individual components calculated at M06 level of theory for some transition metal complexes.
|
μ and α Components, Amplitudes (×10-24 esu) |
|||||
|
|
Ia |
IIb |
IIIc |
IVd |
Ve |
|
αxx αxy αyy αxz αyz αzz αiso αaniso |
58.53 32.19 42.99 -11.78 -9.27 80.66 60.73 69.71 |
58.830 -3.600 72.430 18.520 -0.5800 77.310 69.530 36.680 |
152.50 -8.362 128.55 -17.21 -17.65 58.67 113.24 90.76 |
143.04 -11.58 136.53 -17.44 -20.18 50.97 110.18 102.26 |
64.40 -1.30 65.98 -0.03 -1.27 64.59 64.99 3.49 |
|
γ Components, Amplitudes(×10-36 esu) |
|||||
|
γxxxx γyyyy γzzzz γxxyy γxxzz γyyzz <γ> γ (−ω;ω,0,0)f γ (−2ω;ω,ω,0)f <γ> (p-NA) g |
310.0 123.58 189.13 188.41 170.62 107.65 311.17 235.30 229.94 - |
154.32 95.72 406.08 24.21 56.51 126.83 214.18 - - - |
1051.21 376.44 31.385 269.68 48.049 62.806 494.09 320.71 399.46 - |
1173.2 871.74 12.483 296.40 25.01 331.85 567.03 439.53 284.34 - |
28.04 72.48 38.12 96.87 15.57 17.73 44.93 46.09 20.76 7.29 |
a [(E)-N'-(3,5-dichloro-2-hydroxybenzylidene)benzohydrazide]pyridine copper(II)25
b bis-(2,4-dichloro-6-formylphenoxy)-dipyridine copper(II)22
c bis-[1-(E-(2, 4-dibromophenylimino) methyl) naphthalene-2-olato] copper (II)24
d bis-[1-(E-(2, 4-dibromophenylimino) methyl) naphthalene-2-olato] nickel (II)24
e Present work
f The wavelength ω = 1059.6 nm,
g the average static β// and <γ> amplitude for para-nitroaniline (p-NA) calculated at M06/6-311G* level of theory.
Table 4. The HOMO and LUMO energies and the energy gap (∆E)a of ligand (HL) and its metal complexes.
|
Compounds |
EHOMO ELUMO ∆EHL EHOMO-1 ELUMO+1 ∆E EHOMO-2 ELUMO+2 ∆E |
|
HL Complex (1) Complex (2) Complex (3) |
-7.250 -4.431 2.819 -10.124 -0.758 9.366 -10.773 1.1081 1.881 -7.977 -7.567 0.410 -10.423 -4.389 6.034 -10.448 -4.333 6.115 -6.862 -4.447 2.415 -8.902 -3.457 5.445 -10.111 -0.242 9.869 -9.137 -8.864 0.273 -10.498 -4.125 6.373 -10.651 -3.969 6.682 |
a Energy gap (∆E) = ELUMO-EHOMO; units in eV.
Table 5. Global reactivity descriptors a of ligand (HL) and its metal complexes.
|
Compounds |
IP EA χ η μ ω σ |
|
H2L Complex (1) Complex (2) Complex (3) |
7.250 4.431 5.841 1.4.10 -5.840 12.100 0.355 7.977 7.567 7.772 0.205 -7.772 147.33 2.439 6.862 4.447 5.655 1.208 -5.655 13.239 0.414 9.137 8.864 9.001 0.137 -9.000 296.73 3.663 |
a Ionization potential (IP), electro negativity (χ), electron affinity (EA), chemical potential (μ), global softness (σ), global hardness (η), units are in eV.