Layer-by-layer chemical deposition technique for thin film assembly of deposited nano-sized magnesium(II)–5,7-dinitro-8-hydroxyquinolate: Characterization and spectral–optical–electrical properties

Layer-by-layer (LBL) chemical deposition technique was implemented as a low cost and efficient methodology for rapid synthesis and assembly of deposited thin films of nano-sized magnesium(II)–5,7-dinitro-8-hydroxyquinolate complex, Mg[((NO2)2-8HQ)2]. The stoichiometry of deposited nano-sized complex was characterized as a 1:2 ratio based on metal to ligand without contribution of the nitro-group. Further structural characterization and identification were also monitored by using Fourier Transform infrared spectroscopy (FT-IR) in order to confirm the possible mode of bonding in the deposited nano-sized Mg[((NO2)2-8HQ)2] complex. Thermal gravimetric analysis (TGA) of the ligand and complex were studied and compared to evaluate the possible incorporated thermal stability characteristics. Surface imaging of assembled thin film was performed by using scanning electron microscopy (SEM) to confirm high homogeneity in surface particles distribution with average particle size in the range of 30–50 nm. The absorption spectrum of Mg[((NO2)2-8HQ)2] thin film was recorded in the spectral region 250–1000 nm. The optical transmission and reflection spectra of the films have been recorded within the wavelength range 250–2500 nm. The optical parameters of the films, such as absorption index, α, refractive index, n, band gap, Eg, dielectric constants, ε1 and ε2 and dissipation factor, tan δ, have been also determined. Two activation energies were determined from the temperature dependence of the dark electrical conductivity. Hopping conduction parameters of Mg[((NO2)2-8HQ)2] have been calculated by employing the variable range hopping model.

Graphical abstractThin films assembly of nano-sized magnesium(II)–5,7-dinitro-8-hydroxyquinolate complex, Mg[((NO2)2-8HQ)2] by using surface layer-by-layer chemical deposition method was studied, explored and evaluated on the basis of metal analysis, FT-IR, SEM and TGA. Spectral, optical and electrical properties of Mg[((NO2)2-8HQ)2] thin films were also explored and compared with previously published other metal complexes.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A method of homogeneous thin film assembly of metal complex. ► Nano-sized magnesium(II)–5,7-dinitro-8-hydroxyquinolate complex. ► Surface layer-by-layer chemical deposition method as efficient methodology. ► Structural characterization by using FT-IR, SEM and TGA. ► Spectral, optical and electrical properties of thin film deposited metal complex.