3.8 Powder X-ray diffraction studies

The diffraction of X-rays from the planes of a crystal (diffraction analysis) is considered as one of the important methods of the analytical work. By using X-ray diffraction which depends on the crystal properties of solids, we can identify the crystal structure of various solid compounds and identify the actual compounds from its structure, and we can also determine the arrangement of molecules in crystal [30]. X-ray diffractometry is an important technique as it is a nondestructive, non-contrast, fast, and sensitive one. Obtained XRD data of H2L1 ligand and its La(III) complex 1 of nanoparticle (Figure 2) show that XRD pattern of the ligand is different in comparison with the XRD pattern of the nanocomplex. The obtained data indicate that the complex is more crystalline in nature than that of the ligand which has an amorphous phase. The average particle size of the complex (1) can be estimated from Debye-Scherrer equation (Eq. (2)):

$$\mathbf{L} = K\boldsymbol{\lambda}/\boldsymbol{\beta}\cos\theta\tag{2}$$

where β the breadth of the observed diffraction line at its half intensity maximum; K, the shape factor, 0.89; λ, the wavelength of the X-ray source used in XRD; θ, the corresponding incidence angle.

The average particle size of the nanoparticles is 15 nm. The sharp diffraction peaks of the samples indicate that the well-crystallized lanthanum complex nanocrystals can be prepared by our procedure [23].

### 3.9 EDX spectra

3.6 Magnetic susceptibility

Green Chemistry Applications

�2.2098 � <sup>10</sup>�<sup>6</sup> –(-2.3013 � <sup>10</sup>�<sup>6</sup>

magnetic moment (Table 3).

3.7 Thermal analysis

controlled at 10<sup>o</sup>

(180�300o

24

La nanocomplexes:

bility.

Table 3.

The following equation was used to calculate the magnetic susceptibility of the

Compd. no. μeff (B.M.) Absorption bands (nm)

1 Diamagnetic 269 337 2 Diamagnetic 210 280 3 Diamagnetic 227 279

Magnetic moment and electronic spectral data of La(III) nanocomplexes.

Xg <sup>¼</sup> C bal ð Þð Þ<sup>1</sup> <sup>R</sup> � <sup>R</sup><sup>0</sup> 10�9m

where C, calibration constant of standard; l, length of sample in filled tube; R0

reading of empty sample tube; R, reading with sample; χ<sup>g</sup> gram magnetic suscepti-

The gram magnetic susceptibility of the complexes was found in the range

Thermogravimetric analyses (TGA) of the La nanocomplexes were used to determine the thermal stability of the complexes, decide whether the water molecules are lattice or coordinated, and finally suggest a scheme for thermal decomposition of these chelates. In the present investigation, heating rates were suitably

(1) showed three thermal stages. The first stage represents the loss of H2O molecule of coordination, HNO3 and ½O2 with a found weight loss of 11.72% (cacld. 11.54%)

the organic part (C12H7BrN3O2S2) with an estimated weight loss 44.25% (calcd. 43.94%) leaving 4 C and La metal as a metallic residue. The overall weight loss

measured from the ambient temperature up to � <sup>600</sup><sup>o</sup>

22.60% (calcd. 22.27%). The final stage at 300�520o

within the temperature range of 130�180o

amounts is 78.57% (cacld. 77.75%):

chelate was calculated within the corresponding temperature ranges. Also, TGA curve of the La(III) complex of nanoscale [(La)(L<sup>1</sup>

C min�<sup>1</sup> under nitrogen atmosphere, and the weight loss was

C) corresponds to the loss of C5H3BrN2O with an estimated mass loss of

) cm<sup>3</sup> mol�<sup>1</sup>

show that these complexes are diamagnetic in nature or there is no significant

(1)

, respectively. Negative values of χ<sup>g</sup>

п-п\* n-п\*

C. The weight loss for each

C corresponds to loss of rest of

C; the subsequent second step

)(NO3)(H2O)]

,

The amount of elements present in the percentage level of the metal complexes was identified by EDX data [31]. EDX spectra are used to calculate the percentage level of the elements present in the metal complexes like C, O, N, S, and La that are present in the La(IIl) nanocomplex 2, shown in Figure 3. The revealed data are in good agreement with that of the elemental analysis.

### 3.10 SEM analysis

SEM technique was used to study the morphology and size of nanoparticles (Figure 4). It seems that the particles are semispherical with some agglomerations

Figure 2. X-ray powder diffractogram of complex (1) nanoparticle.

of the particles. The SEM images further revealed the stabilization of La(III) 1 nanoparticles due to interaction with the Schiff base ligand; this stabilization facilitates penetration of tumor cell membrane and causes the destruction of tumor cell [32].

3.11 TEM analysis

DOI: http://dx.doi.org/10.5772/intechopen.83558

Figure 6.

Figure 7.

27

Suggested structure of metal complexes 1–3.

Geometry-optimized structures of (a) complex 1( b) La complex 2.

Transmission electron microscopy (TEM) can be used to directly image nanoparticles at scales approaching a single atom. TEM analysis is performed to examine the size and shape of the nanoparticles. The La(III) complex 2 nanoparticle was fairly uniform in size, spherical in shape, and with the average diameter

Synthesis and Characterization of Nanocomplexes by Green Chemistry and Their Applications…

Figure 3. EDX spectra of nano-La(III) complex 2.

Figure 4. SEM images of nanoparticles as produced by ultrasound [(La)(L1 )(NO3)(H2O)] (1).

Figure 5. TEM image of La(III) nanocomplex 2.

Synthesis and Characterization of Nanocomplexes by Green Chemistry and Their Applications… DOI: http://dx.doi.org/10.5772/intechopen.83558
