Ligand C24H25N3O4,ðHL<sup>21</sup><sup>Þ</sup>

Ethanolic solution of 3-formyl-6-methyl-chromone (1mmol) and 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one (1mmol) was stirred at room temperature, then refluxed for 2h, and kept at Transition Metal Complexes with Antipyrine‐Derived Schiff Bases: Synthesis and Antibacterial Activity http://dx.doi.org/10.5772/67584 75

Figure 12. Scheme of synthesis of complexes with ligands HL17 and HL20.

Figure 13. Scheme of synthesis of complexes with ligand HL18.

The study methods used to characterize the metal complexes were as follows: elemental analysis, the thermogravimetric analysis, IR, UV-Vis, EPR spectroscopy, the molar electric

HL16: R = OCH3

stirred 1- 2h CH3 OH/CH3 CH2 OH

refluxed 36h

CH3 OH/CH3 CH2 OH/KNO3

HL15: R = OH; M= Cu2+, Co2+, Mn2+,Ni2+, Zn2+, Cd2+, Hg2+, VO2+; X = 0; Y = Cl

Y2

; M= Cu2+, Co2+, Ni2+, Zn2+ ; X = Cl; Y = 0

Ligand C24H25N3O4,ðHL<sup>21</sup><sup>Þ</sup>

Ethanolic solution of 3-formyl-6-methyl-chromone (1mmol) and 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one (1mmol) was stirred at room temperature, then refluxed for 2h, and kept at

conductibility, the magnetic susceptibility, and the X-ray diffraction.

Figure 11. Scheme of synthesis of complexes with ligands HL15 and HL16.

CH3 OH/CH3 CH2 OH

refluxed 5-6h

MCl2

OHC

74 Descriptive Inorganic Chemistry Researches of Metal Compounds

2.2.1.1. Synthesis of the complexes with ligand HL<sup>21</sup>

n = 2 for M = Cr(III) and n = 1 for M = Cu(II), Co(II), Mn(II), Ni(II)

Figure 14. Scheme of synthesis of complexes with ligand HL19.

4�C for 2days. The resulting precipitate of intense yellow color was filtered, washed with methanol, and dried. Yellow single crystals suitable for structure determination were obtained from methanolic solution upon slow evaporation at room temperature [65].

Complexes 1–3 and 5–9 were prepared by direct reaction between the ligand and the corresponding metal salts, while complex 4 was prepared by the metathetical displacement of the acetate ion, in Cu(OAc)2�H2O, by the thiocyanate ion [65] (Figures 15, 16).

$$\left[\mathbf{Cu\_2L^{21}Cl\_2}\right] \tag{1}$$

To CuCl2�2H2O (2mmol) dissolved in aqueous/ethanol solution (1:2v/v) was added ligand HL<sup>21</sup> (2mmol) dissolved in hot ethanol and refluxing for 2h. The green-brown precipitate, which separated on cooling, was filtered, washed with hot water, ethanol followed by ether, and dried in vacuo.

$$[\mathbf{CuL^{21}(NO\_3)}]\tag{2}$$

Complex 2 was prepared similarly, using Cu(NO3)2�3H2O (2mmol). Green solid.

$$[\mathbf{CuL^{21}(OAc)}]\mathbf{CH\_3OH}\tag{3}$$

Complex 3 was prepared similarly, using Cu(OAc)2�H2O (2mmol). Brown solid, X-ray quality single crystals were obtained.

$$\left[\mathbf{CuL^{21}(SCN)}\right] \tag{4}$$

For the synthesis of complex 4, the acetate complex was first prepared and the acetate ion was then displaced by thiocyanate ion by using KSCN (2mmol). Dark-green solid.

Figure 15. X-ray molecular structure of ligand HL<sup>21</sup> and complex 3.

Transition Metal Complexes with Antipyrine‐Derived Schiff Bases: Synthesis and Antibacterial Activity http://dx.doi.org/10.5772/67584 77

Figure 16. Proposed structures of the metal complexes 1–9.

4�C for 2days. The resulting precipitate of intense yellow color was filtered, washed with methanol, and dried. Yellow single crystals suitable for structure determination were obtained

Complexes 1–3 and 5–9 were prepared by direct reaction between the ligand and the corresponding metal salts, while complex 4 was prepared by the metathetical displacement of the acetate ion,

To CuCl2�2H2O (2mmol) dissolved in aqueous/ethanol solution (1:2v/v) was added ligand HL<sup>21</sup> (2mmol) dissolved in hot ethanol and refluxing for 2h. The green-brown precipitate, which separated on cooling, was filtered, washed with hot water, ethanol followed by ether,

Complex 3 was prepared similarly, using Cu(OAc)2�H2O (2mmol). Brown solid, X-ray quality

For the synthesis of complex 4, the acetate complex was first prepared and the acetate ion was

Complex 2 was prepared similarly, using Cu(NO3)2�3H2O (2mmol). Green solid.

then displaced by thiocyanate ion by using KSCN (2mmol). Dark-green solid.

Figure 15. X-ray molecular structure of ligand HL<sup>21</sup> and complex 3.

<sup>½</sup>Cu2L21Cl2� (1)

<sup>½</sup>CuL21ðNO3Þ� (2)

<sup>½</sup>CuL<sup>21</sup>ðOAcÞ�CH3OH (3)

<sup>½</sup>CuL<sup>21</sup>ðSCNÞ� (4)

from methanolic solution upon slow evaporation at room temperature [65].

in Cu(OAc)2�H2O, by the thiocyanate ion [65] (Figures 15, 16).

76 Descriptive Inorganic Chemistry Researches of Metal Compounds

and dried in vacuo.

single crystals were obtained.

$$\left[\mathbf{CuL}^{21}(\mathbf{H\_2O})(\mathbf{ClO\_4})\right] \tag{5}$$

Complex 5 was prepared similarly, using Cu(ClO4)2�6H2O (2mmol). The mixture was stirred at room temperature for 1h, when a dark-green precipitate appeared immediately.

$$[\mathbf{Cu\_2(L^2)\_2(H\_2O)\_4]SO\_4} \tag{6}$$

Complex 6 was prepared similarly, using CuSO4�5H2O (2mmol). The mixture was stirred at reflux temperature for 4h, when appeared a dark-green precipitate.

$$\left[\text{Ni}(\text{L}^{\text{21}})\_{\text{2}}\right] \tag{7}$$

Complex 7 was prepared similarly, using NiCl2�6H2O (2mmol). Green to yellow solid.

$$\left[\mathbf{VO}(\mathbf{L}^{\text{21}})\_{\text{2}}\right] \tag{8}$$

Complex 8 was prepared similarly, using VOSO4�2H2O (2mmol). Brown solid.

$$\left[\mathbf{M}\mathbf{n}(\mathbf{L}^{21})\_2\right] \tag{9}$$

Complex 9 was prepared similarly, using Mn(ClO4)2�6H2O (2mmol). Orange solid.

2.2.1.2. Synthesis of the complexes with ligand HL<sup>22</sup>

$$\text{Light} \gets\_{19} \text{H}\_{19} \text{N}\_{3}\text{O}\_{3}, (\text{HL}^{22})$$

The ligand HL22 was synthesized by refluxing equimolar amounts of 4-amino-2,3-dimethyl-1 phenyl-3-pyrazolin-5-one and 2-hydroxy-4-methoxy-benzaldehyde in ethanol according to the experimental protocol described in Ref. [66].

Complexes 10–12, 14, and 15 were prepared by the direct reaction between the ligand and the corresponding metal salts. Complex 13 was obtained by refluxing a mixture of CuCl2�2H2O and 1-phenyl-2,3-dimethyl-4-(N-2-hydroxy-4-methoxy-benzaldehyde)-3-pyrazolin-5-one with the addition of KSCN (Figures 17, 18) [66].

$$\left[\mathbf{CuL^{22}Cl(H\_2O)}\right] \tag{10}$$

An ethanol solution of CuCl2�2H2O (2mmol, 15mL aqueous/ethanol 1:2 v/v) was added dropwise to a stirred ethanol solution of the Schiff base ligand HL<sup>22</sup> (2mmol, 15mL). The resulting solution was stirring for 3h at room temperature. The green-brown colored solid was filtered, washed with hot water, ethanol followed by ether, and dried in vacuo.

Figure 17. X-ray molecular structure of ligand HL<sup>22</sup> and complex 12.

Transition Metal Complexes with Antipyrine‐Derived Schiff Bases: Synthesis and Antibacterial Activity http://dx.doi.org/10.5772/67584 79

Figure 18. Proposed structures of the metal complexes 10–15.

<sup>½</sup>NiðL<sup>21</sup>Þ2� (7)

<sup>½</sup>VOðL<sup>21</sup>Þ2� (8)

<sup>½</sup>MnðL<sup>21</sup>Þ2� (9)

<sup>½</sup>CuL22ClðH2OÞ� (10)

Complex 7 was prepared similarly, using NiCl2�6H2O (2mmol). Green to yellow solid.

Complex 8 was prepared similarly, using VOSO4�2H2O (2mmol). Brown solid.

Complex 9 was prepared similarly, using Mn(ClO4)2�6H2O (2mmol). Orange solid.

Ligand C19H19N3O3,ðHL<sup>22</sup><sup>Þ</sup>

The ligand HL22 was synthesized by refluxing equimolar amounts of 4-amino-2,3-dimethyl-1 phenyl-3-pyrazolin-5-one and 2-hydroxy-4-methoxy-benzaldehyde in ethanol according to the

Complexes 10–12, 14, and 15 were prepared by the direct reaction between the ligand and the corresponding metal salts. Complex 13 was obtained by refluxing a mixture of CuCl2�2H2O and 1-phenyl-2,3-dimethyl-4-(N-2-hydroxy-4-methoxy-benzaldehyde)-3-pyrazolin-5-one with

An ethanol solution of CuCl2�2H2O (2mmol, 15mL aqueous/ethanol 1:2 v/v) was added dropwise to a stirred ethanol solution of the Schiff base ligand HL<sup>22</sup> (2mmol, 15mL). The resulting solution was stirring for 3h at room temperature. The green-brown colored solid

was filtered, washed with hot water, ethanol followed by ether, and dried in vacuo.

2.2.1.2. Synthesis of the complexes with ligand HL<sup>22</sup>

78 Descriptive Inorganic Chemistry Researches of Metal Compounds

experimental protocol described in Ref. [66].

the addition of KSCN (Figures 17, 18) [66].

Figure 17. X-ray molecular structure of ligand HL<sup>22</sup> and complex 12.

$$[\mathbf{CuL^{22}(NO\_3)(H\_2O)\_2}]\tag{11}$$

Complex 11 was prepared similarly, using Cu(NO3)2�3H2O (2mmol). Dark-green solid.

$$\left[\mathbf{Cu}(\mathbf{L}^{\mathfrak{D}})\_{\mathfrak{z}}\right] \tag{12}$$

Complex 12 was prepared similarly, using Cu(OAc)2�H2O (2mmol). Brown solid, X-ray quality single crystals were obtained.

$$\left[ (\mathbf{CuL^{22}(SCN)(H\_2O)\_2}) \right] \tag{13}$$

For the synthesis of complex 13, the chloride complex was first prepared and chloride ion was then displaced by thiocyanate ion by using KSCN (2mmol). The green colored solid, which separated on cooling, were filtered, washed with hot water, ethanol followed by ether and dried in vacuo.

$$\begin{bmatrix} \mathbf{[Cut^{22}(CIO\_4)(H\_2O)\_2]} \end{bmatrix} \tag{14}$$

Complex 14 was prepared similarly, using Cu(ClO4)2�6H2O (2mmol). Green solid.

$$\left[\mathbf{Cu}\_2(\mathbf{L}^{\mathsf{ZF}})\_2(\mathbf{H}\_2\mathbf{O})\_4\right]\mathbf{SO}\_4\tag{15}$$

Complex 15 was prepared similarly, using CuSO4�5H2O (2mmol). Dark-green solid.

2.2.1.3. Synthesis of the complexes with ligand HL<sup>23</sup>
