Synthesis, Characterization, and Photophysical Studies of Some

Hindawi Publishing Corporation International Journal of Inorganic Chemistry Volume 2013, Article ID 212435, 7 pages http://dx.doi.org/10.1155/2013/212435

Research Article Synthesis, Characterization, and Photophysical Studies of Some Novel Ruthenium(II) Polypyridine Complexes Derived from Benzothiazolyl hydrazones Shaikh Khaled,1 Mohammed Zamir Ahmed,1 Firdous G. Khan,2 and Shaikh Kabeer Ahmed3 1

Organic Chemistry Research Laboratory, Yeshwant Mahavidyalaya, Nanded, Maharashtra 431602, India School of Chemical Sciences, Swami Ramanand Teerth Marathwada University, Nanded, Maharashtra 431606, India 3 P.G. Department of Chemistry, Sir Sayyed College of Arts, Commerce & Science, Aurangabad, Maharashtra 431001, India 2

Correspondence should be addressed to Shaikh Kabeer Ahmed; [email protected] Received 30 April 2013; Revised 19 July 2013; Accepted 3 August 2013 Academic Editor: Wolfgang Linert Copyright © 2013 Shaikh Khaled et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A series of five benzothiazolylhydrazone ligands 3a–3e and their seven novel Ru(II) polypyridine complexes 4a–4d, 5a, 5d, 5e of the type [Ru(N–N)2 (L)]Cl2 , where (N–N)2 is 2,2󸀠 -bipyridine (bpy)2 or 1,10-phenanthroline (phen)2 and (L) is ligands 3a– 3e, have been synthesized and characterized by elemental analysis, IR, 1 H NMR, electronic absorption, and emission spectral studies. The interpretation of the analytical data revealed that the ligands coordinate with the metal ion in a bidentate fashion through azomethine nitrogen and phenolic oxygen to form complexes. These ligands and complexes also exhibit absorption and luminescence properties.

1. Introduction In the last two decades, Ru(II) complexes have been widely studied in the field of inorganic chemistry [1–5]. The polypyridine complexes of Ru(II) have been studied extensively with the point of interest being their rich and well characterized photophysics [6, 7]. In recent years, transition metal complexes have been used extensively in the fore front of fields such as probes of DNA structure, DNAdependent electron transfer, and site-specific DNA cleavage [8–10]. The area of metal complexes with hydrazones has been investigated intensively during the last years regarding their pharmacological applications such as tuberculostatic, antitumor, antibacterial, and antifungal agents [10–12]. The thiazole and benzothiazole hydrazone represent a very interesting class of ligands, due to additional donor sites: nitrogen, sulphur, or oxygen atom which introduce a wide range in their coordinative and pharmaceutical properties [10, 13–15]. In the context of this, we synthesized and characterized five ligands 2-(2󸀠 -hydroxy-3󸀠 -iodo-5󸀠 -chloro acetophenyl)

benzothiazolylhydrazone 3a, 2-(2󸀠 ,4󸀠 -dihydroxy acetophenyl) benzothiazolylhydrazone 3b, 2-(2󸀠 ,5󸀠 -dihydroxy acetophenyl) benzothiazolylhydrazone 3c, 2-(2󸀠 -hydroxy-5󸀠 chloro acetophenyl) benzothiazolylhydrazone 3d, 2-(2󸀠 -hydroxy-4󸀠 -methyl-5󸀠 -chloro acetophenyl) benzothialylhydrazone 3e, and their seven Ru(II) polypyridine complexes: [Ru(bpy)2 3a]Cl2 4a, [Ru(bpy)2 3b]Cl2 4b, [Ru(bpy)2 3c]Cl2 4c, [Ru(bpy)2 3d]Cl2 4d, [Ru(phen)2 3a]Cl2 5a, [Ru(phen)2 3d]Cl2 5d, and [Ru(phen)2 3e]Cl2 5e.

2. Experimental 2.1. Materials and Methods. All reagents and solvents were purchased commercially and were used as received. 2Mercaptobenzothiazole, hydrazine hydrate, acetophenone, and RuCl3 ⋅ 3H2 O were obtained from SD Fine-chem limited (India). The compounds 3a–3e [13], [Ru(bpy)2 Cl2 ] ⋅ nH2 O and [Ru(phen)2 Cl2 ] ⋅ nH 2 O, and the metal complexes 4a– 4d, 5a, 5d, and 5e [16] were synthesized according to the literature methods. Elemental analysis was carried out on

2

International Journal of Inorganic Chemistry N SH + NH2 NH2 H2 O

N

EtOH, reflux

S

NH

4h

S

+ H2 S NH2

O

N NH NH2

S

+ H3 C

R

C

HO EtOH, reflux, 4 h CH3

N NHN

C

R + H2 O

S HO where R = 3a. 3-I, 5-Cl; 3b. 4-OH; 3c. 5-OH; 3d. 5-Cl; 3e. 4-CH 3 , 5-Cl.

Scheme 1: Synthetic route of ligands 3a–3e.

a PerkinElmer 240Q elemental analyzer. The infrared spectra were recorded on a Shimadzu FTIR-8400 spectrometer in KBr pellets. 1 H NMR spectra were recorded on a 500 MHz Bruker FT-NMR spectrometer using CDCl3 , and all chemical shifts are given relative to TMS. UV-Vis spectra were recorded on a Shimadzu UV-1601 spectrophotometer, and the emission spectra were recorded on a shimadzu RF-5000 luminescence spectrophotometer at room temperature. Thermogravimetric analysis was performed on a computer-controlled TA Instrument 2050 TGA analyzer into alumina pans at a heating rate of 10∘ C/min. 2.2. Synthesis of Ligands. The ligands utilized in the present investigation were synthesized by the condensation reaction 2-hydrazinobenzothiazole with substituted acetophenones. 2-Hydrazinobenzothiazole was prepared by the addition of hydrazine hydrate (1 mmol) to the warm solution of 2mercaptobenzothiazole (1 mmol) in absolute ethyl alcohol (10 mL), and the mixture was refluxed on a water bath for 4 hours or until H2 S gas ceased to evolve. The reaction mixture was concentrated and cooled. The white needle-like crystals, separated were filtered, and recrystallized from ethanol. To a warm ethanolic solution of 2-hydrazinobenzothiazole (1 mmol, in 10 mL) an ethanolic solution of respective acetophenones (1 mmol, in 10 mL) was added, and the mixture was refluxed for 4 hours on a water bath, the precipitate was obtained; it was filtered, washed, and recrystallized from ethanol, as shown in Scheme 1. 2.3. Synthesis of the Complexes. A hot ethanolic solution of the respective ligands 3a–3e (1 mmol, in 10 mL) was mixed with an ethanolic solution of respective hydrated Ru(II) 2,2󸀠 bipyridyl chloride or Ru(II) 1,10 phenanthroline chloride (1 mmol in 10 mL), and the mixture was refluxed on a water bath for 4 hours, and then cooled to room temperature. On cooling, a colored solid product was formed. The solid was filtered, washed with ethanol, then ether, and

dried. Crystallization from ethanol gave the desired metal complexes shown in Schemes 2 and 3.

3. Results and Discussion The five benzothizolyl ligands 3a–3e were synthesized by utilizing the 2-hydrazinobenzothiazole via condensation reaction with substituted acetophenones. These synthesized ligands 3a–3e were further reacted with hydrated Ru(II) 2,2󸀠 bipyridine chloride or Ru(II) 1,10 phenanthroline chloride to obtain polypyridine complexes 4a–4d, 5a, 5d, and 5e. The structures of the synthesized ligands and their complexes were confirmed on the basis of physical, analytical and spectral data mentioned in Tables 1 and 2. 3.1. Characterization of the Ligands and Complexes 3.1.1. IR and 1 H NMR Spectra. The IR and 1 H NMR spectral data of the ligands 3a–3e and complexes 4a–4d, 5a, 5d, and 5e are listed in Table 2. The IR spectrum of all the ligands 3a– 3e exhibits a broad strong band at 3400–3350 cm−1 , due to the phenolic OH group stretching vibration which disappears in the spectra of the complexes, indicating the coordination of these ligands through the phenolic oxygen [12, 13, 15]. It is also supported by the shift to lower wave numbers of the band from 1467–1450 cm−1 , to 1438–1413 cm−1 due to the stretching vibration of C–O phenolic when compared to the uncomplexed ligands [3, 14, 15, 17]. In all the five ligands 3a–3e, a strong band at 1600– 1590 cm−1 due to the azomethine group is observed. On complexation, this band was shifted to as lower frequency in the 1564–1404 cm−1 region indicating the coordination of the azomethine nitrogen atom to the metal ion [13, 15, 18]. It is further confirmed by the downward shift of the bands due to ](N–H), ](N–N), ](C–N, cyclic), and ](C–S– C) [14, 17, 19] and the appearance of new additional bands in

International Journal of Inorganic Chemistry

3

Table 1: Physical and analytical data of ligands and their complexes. CC 3a 3b 3c 3d 3e

Yield (%) 90 90 85 90 90

Colour Pale brown Yellow Dirty green Dirty yellow Pale yellow

MP (∘ C)

Empirical formula

225

C15 H11 N3 OSClI

185

C15 H13 N3 O2 S

160

C15 H13 N3 O2 S C15 H12 N3 OSCl

220

C16 H14 N3 OSCl

210

Elemental analysis found (Calcd.) (%) H N S

C

4a

90

Dirty yellow

224

RuC35 H26 N7 OCl3 SI

4b

90

Black

270

RuC35 H28 N7 O2 Cl2 S

4c

85

Brown

210

RuC35 H28 N7 O2 Cl2 S

4d

90

Dark brown

310

RuC35 H27 N7 OCl3 S

5a

85

Brown

225

RuC39 H26 N7 OSCl3 I

5d

90

Dark brown

290

RuC39 H27 N7 OSCl3

5e

90

Brown

215

RuC40 H29 N7 OSCl3 I

40.59

2.44

(40.63

2.48

9.48

7.22)

60.16

4.29

14.01

10.67

(60.20

4.34

14.04

10.70)

60.15

4.29

13.98

10.68

(60.20

4.34

14.04

10.70)

56.72

3.75

13.19

10.05

(56.78

3.78

13.24

10.09)

57.97

4.19

12.61

9.62

(58.00

4.22

12.65

9.66)

45.29 (45.35 53.64 (53.70 53.64 (53.70 52.46 (52.50 47.98 (48.04 55.12 (55.18 48.49 (48.53

2.76 2.80 3.54 3.58 3.53 3.58 3.32 3.37 2.61 2.66 3.12 3.18 2.89 2.93

10.54 10.58 12.49 12.53 12.49 12.53 12.20 12.25 10.01 10.06 11.50 11.55 9.84 9.90

3.41 3.45 4.02 4.09 4.05 4.09 3.95 4.00 3.24 3.28 3.74 3.77 3.18 3.23

CC: compound code.

N

CH3

Cl

R

N

NHN C

+

S

Cl N

Ru N

N

HO (3a–3d)

EtOH/H2 O reflux, 4 h

2+

R H3 C C N

H N

N

O

S N

N

Ru N

N

(4a–4d)

Scheme 2: Synthesis of complexes 4a–4d.

9.43

Ru

7.18

10.84 10.90) 12.86 12.91) 12.87 12.91) 12.58 12.62) 10.30 10.36) 11.86 11.91) 10.16 10.21)

4

International Journal of Inorganic Chemistry Table 2: IR and 1 H NMR spectral data of ligands and their complexes.

CC 3a 3b 3c 3d 3e 4a

4b

4c

4d

5a

5d

5e

IR (KBr, Cm−1 ), ] 3400 (OH), 3195 (N–H), 1596 (C=N), 1590 (C=N, cyclic), 1510 (N–N), 1450 (C–O), 1280 (C–N), 860 (C–S) 3352 (OH), 3174 (N–H), 1598 (C=N), 1552 (C=N, cyclic), 1512 (N–N), 1467 (C–O), 1274 (C–N), 863 (C–S) 3350 (OH), 3198 (N–H), 1590 (C=N), 1588 (C=N, cyclic), 1510 (N–N), 1452 (C–O), 1280 (C–N), 860 (C–S) 3400 (OH), 3204 (N–H), 1595 (C=N), 1585 (C=N, cyclic), 1500 (N–N), 1465 (C–O), 1280 (C–N), 860 (C–S) 3400 (OH), 3190 (N–H), 1600 (C=N), 1590 (C=N, cyclic), 1510 (N–N), 1456 (C–O), 1280 (C–N), 860 (C–S) 3198 (N–H), 1598 (C=N, cyclic), 1404 (C=N), 1502 (N–N), 1430 (C–O), 1282 (C–N), 858 (C–S), 745 (bpy ring), 651 (H2 O), 495 (Ru–N), 418 (Ru–O) 3380 (OH), 3200 (N–H), 1594 (C=N, cyclic), 1450 (C=N), 1504 (N–N), 1438 (C–O), 1280 (C–N), 860 (C–S), 740 (bpy ring), 650 (H2 O), 498 (Ru–N), 450 (Ru–O) 3363 (OH), 3194 (N–H), 1593 (C=N, cyclic), 1468 (C=N), 1505 (N–N), 1422 (C–O), 1280 (C–N), 860 (C–S), 736 (bpy ring), 650 (H2 O), 495 (Ru–N), 418 (Ru–O) 3208 (N–H), 1602 (C=N, cyclic), 1466 (C=N), 1508 (N–N), 1415 (C–O), 1285 (C–N), 856 (C–S), 768 (bpy ring), 651 (H2 O), 520 (Ru–N), 445 (Ru–O) 3196 (N–H), 1602 (C=N, cyclic), 1465 (C=N), 1502 (N–N), 1413 (C–O), 1282 (C–N), 1056 (phen ring), 650 (H2 O), 510 (Ru–N), 438 (Ru–O) 3205 (N–H), 1602 (C=N, cyclic), 1564 (C=N), 1503 (N–N), 1428 (C–O), 1278 (C–N), 862 (C–S), 1056 (phen ring), 651 (H2 O), 515 (Ru–N), 419 (Ru–O) 3208 (N–H), 1594 (C=N, cyclic), 1465 (C=N), 1500 (N–N), 1423 (C–O), 1289 (C–N), 858 (C–S), 1105 (phen ring), 650 (H2 O), 511 (Ru–N), 423 (Ru–O)

H NMR (CDCl3 , 500 MHz, ppm), 𝛿 2.49 (s, 3H, CH3 ), 7.00 (s, 1H, NH), 7.21 (m, 2H, ArH), 7.45 (m, 4H, ArH), 13.94 (s, 1H, br, OH) 2.45 (s, 3H, CH3 ), 7.00 (s, 1H, NH), 7.19 (m, 3H, ArH), 7.37 (s, 4H, ArH), 12.60 (s, 2H, br, two OH) 2.40 (s, 3H, CH3 ), 6.90 (s, 1H, NH), 7.10 (m, 3H, ArH), 7.21 (m, 4H, ArH), 12.01 (s, 2H, br, two OH) 2.45 (s, 3H, CH3 ), 7.00 (s, 1H, NH), 7.19 (m, 3H, ArH), 7.37 (s, 4H, ArH), 12.60 (s, 1H, br, OH) 2.41 (d, 6H, two CH3 ), 6.90 (s, 1H, NH), 7.30 (m, 7H, ArH), 12.30 (s, 1H, br, OH) 1

2.41 (s, 3H, CH3 ), 6.81 (s, 1H, NH), 7.05 (m, 3H, ArH), 7.41 (m, 4H, ArH), 7.58 (m, 8H, bpy protons), 7.81 (m, 8H, bpy, protons) 2.41 (s, 3H, CH3 ), 6.93 (s, 1H, NH), 7.10 (m, 3H, ArH), 7.34 (m, 4H, ArH), 7.58 (m, 8H, bpy protons), 7.81 (m, 8H, bpy protons), 13.92 (s, 1H, br, OH) 2.39 (s, 3H, CH3 ), 6.92 (s, 1H, NH), 7.10 (m, 3H, ArH), 7.33 (m, 4H, ArH), 7.58 (m, 8H, bpy protons), 7.81 (m, 8H, bpy protons), 13.94 (s, 1H, br, OH) 2.41 (s, 3H, CH3 ), 6.93 (s, 1H, NH), 7.21 (m, 3H, ArH), 7.43 (m, 4H, ArH), 7.58 (m, 8H, bpy protons), 7.81 (m, 8H, bpy protons) 2.43 (s, 3H, CH3 ), 6.87 (s, 1H, NH) 7.11 (m, 3H, ArH), 7.41 (m, 4H, ArH), 7.58 (m, 8H, phen protons), 7.80 (m, 8H, phen protons) 2.41 (s, 3H, CH3 ), 6.89 (s, 1H, NH), 7.11 (m, 3H, ArH), 7.41 (m, 4H, ArH), 7.55 (m, 8H, phen protons), 7.80 (m, 8H, phen protons) 2.31 (s, 3H, CH3 ), 2.46 (s, 3H, CH3 ), 7.03 (s, 1H, NH), 7.14 (m, 2H, ArH), 7.17 (s, 4H, ArH), 7.58 (m, 8H, phen protons), 7.80 (m, 8H, phen protons), 12.67 (s, 1H, br, OH)

CC: compound code.

N

CH3 NHN C

R

N +

S

Cl Cl Ru N N

HO (3a, 3d, and 3e)

EtOH/H2 O reflux, 4 h

2+

R H3 C C N S

H N

N N

O Ru

N

N N

(5a, 5d, and 5e)

Scheme 3: Synthesis of complexes 5a, 5d, and 5e.

N


5 2.5

Table 3: Absorption and emission spectral data of ligands and complexes. Absorption 𝜆 nm 330, 364, 370, 384 307, 323, 331, 361, 389 323, 345, 359, 376 300, 322, 337, 364, 369, 384 297, 314, 332 298, 312, 323

Emission 𝜆 nm 550 545 535 540 620 625

3a

2.0 Absorption (a.u.)

Compounds 3a 3d 3e 4a 5a 5e

1.5

3e

1.0

3d

0.5 0.0

3.1.2. UV-Vis Absorption and Emission Spectral Study. The UV-vis absorption spectra of ligands 3a, 3d, and 3e and metal complexes 4a, 5a, and 5e are shown in Figures 1 and 2, and the spectral data are listed in Table 3. In the UV-vis absorption spectra of ligands 3a, 3d, and 3e, the absorption at 330, 323, and 323 nm is attributed to 𝜋-𝜋∗ transitions involving the benzothiazolylhydrazone [10, 29]. The band observed at 370 nm is assigned to the 𝜋-𝜋∗ transition of azomethine (C=N) group [30]. The other absorption bands of the ligands are due to various 𝑛-𝜋∗ and

250

300

350

400

𝜆 (nm)

Figure 1: UV-Vis Absorption spectrum of Ligands 3a, 3d, and 3e. 2.5

2.0 Absorption (a.u.)

the regions 1105–1056 cm−1 and 768–736 cm−1 due to phen/ bpy ring –C–H and –C=N stretching vibrations, respectively [20, 21]. Again, the bands appeared in the range 650 cm−1 were attributed to coordinated water molecule and bands observed due to ]Ru–N and ]Ru–O stretching vibrations in the range of 520–495 cm−1 and 450–418 cm−1 , respectively [17, 22–25]. In the 1 H NMR spectrum of the ligands 3a–3e, a singlet observed at 𝛿 12–14 ppm for one proton corresponds to the 𝛿 Phenolic of the hydrazone ring. The metal complexes of these ligands did not show any proton signal to the phenolic OH range which suggested that the phenolic oxygen participated in the coordination, after complete deprotonation [5, 14, 26]. In addition to this, the singlet observed at 𝛿 7 ppm for one proton in 3a–3e is assigned to the NH proton of benzothiazolylhydrazone. Two multiplet signals observed around 𝛿 7-8 ppm for four protons and three protons of ligands 3a, 3e and four protons of ligands 3b, 3c, and 3d were assigned to aromatic protons [5, 12, 27]. In addition to these, one singlet peak observed at 𝛿 2.40 ppm for three protons in 3a–3e is assigned to methyl group attached to the hydrazone ring. A singlet peak observed at 𝛿 2.31 ppm for three protons in 3e is assigned to methyl group attached to the phenyl ring [12, 20, 27]. In the 1 H NMR spectra of the all complexes, the NH protons, aromatic protons, and the protons of methyl group of ligands are shifted downfield due to coordination to the metal ions [5, 12, 26, 27]. Two multiplet signals of eight protons observed in the spectrum of the complexes 4a–4d at 𝛿 7.58 ppm and 𝛿 8.31 ppm were assigned to bipyridyl protons, and the signals at 𝛿 7.35–7.58 ppm and 𝛿 7.80 ppm in the spectrum of complexes 5a, 5d, and 5e were assigned to phen protons [20, 21, 28]. Thus, all the protons were found to be in their expected region. The conclusions drawn from these studies further support the mode of bonding discussed in their IR spectra.

4a

1.5 1.0

5e

0.5

5a

0.0 300

350 𝜆 (nm)

400

Figure 2: UV-Vis Absorption spectrum of complexes 4a, 5a, and 5e.

𝜋-𝜋∗ transitions [5, 14, 27, 29]. In the UV-vis absorption spectra of complexes and the bands at 322, 332, and 323 nm should receive a dominant contribution from transition involving the ligands 3a, 3d, 3e, respectively [6, 14, 28]. In particular, the bands with 290–300 nm range should receive a dominant contribution from 𝜋-𝜋∗ transition involving bpy and phen moieties [7, 31–33]. The other weak absorption bands of the complexes in the UV region are expected to include contributions from spin-allowed metal to ligand charge transfer, MLCT [5, 27, 29]. The emission spectra of ligands 3a, 3d, and 3e and metal complex 4a in chloroform at room temperature are shown in Figures 3 and 4, and the relevant data is mentioned in Table 3. The luminescence of the ligands 3a, 3d, and 3e are assigned to the benzothiazolylhydrazone centered 𝜋-𝜋∗ level [4, 34–36]. The ligands 3a, 3d, and 3e showed the emission bands at 550 nm, 545 nm, and 535 nm, respectively. The metal complexes 4a, 5a, and 5e showed the emission bands at 540 nm, 620 nm, and 625 nm, respectively. The complexes of Ru(II) are probably the most investigated inorganic luminophores [31, 37]. The metal complexes studied here exhibit relatively intense luminescence. In particular, emissions of complexes should originate from

6


4. Conclusion 3.5

We have investigated the synthesis of seven novel polypyridine complexes of Ru(II) with five benzothiazolylhydrazone ligands. The analytical, thermogravimetrical, IR, 1 H NMR, electronic absorption and emission spectral data revealed that the ligands 3a–3e coordinate with the metal ions in a bidentate fashion through azomethine nitrogen and phenolic oxygen to form complexes 4a–4d, 5a, 5d, and 5e.

Emission intensity (a.u.)

3.0 2.5 2.0 3e

1.5

3d

Acknowledgments

1.0 0.5

3a

0.0 400

450

500

550 𝜆 (nm)

600

650

700

References

Figure 3: Emission spectrum of ligands 3a, 3d, and 3e.

3.5

Emission intensity (a.u.)

3.0 2.5 2.0 1.5 1.0 0.5 0.0

400

450

500

550 𝜆 (nm)

600

650

The authors are thankful to the Principal of Yeshwant Mahavidyalaya, Nanded, for providing necessary facilities for the research work. One of the authors, Shaikh Khaled, is also thankful to NCL, Pune, for providing spectral analysis data.

700

Figure 4: Emission spectrum of complex 4a.

Ru-bpy and Ru-phen CT state [6, 9, 29, 37]. The metal complexes exhibited the usual MLCT emission [5, 37]. 3.1.3. Thermogravimetric Analysis Study. The TG curves of the complexes showed an endothermic peak at 160–200∘ C due to the loss of coordinated water [37], which is in agreement with the results obtained from the IR spectra. The endothermic peaks observed at 340∘ C correspond to the removal of the anionic chloride [38]. All the complexes lose the organic ligand in a large exothermic process, in the range of 400–800∘ C [39]. On the basis of analytical, thermogravimetrical, IR, 1 H NMR, analysis electronic absorption and emission spectral data, it can be concluded that the ligands 3a–3e act as bidentate NO donor in all the complexes.

[1] P. Desjardins, P. A. Glenn, and J. Robert, “Tetrakis (pyridine) ruthenium trans complexes of Phenyl cyanamide ligands: crystallography, electronic absorption spectroscopy, and cyclic voltammetry,” Journal of Inorganic Chemistry, vol. 38, no. 25, pp. 5901–5905, 1999. [2] D. Hesek, Y. Inoue, S. R. L. Everitt, H. Ishida, M. Kunieda, and M. G. B. Drew, “Diastereoselective preparation and characterization of ruthenium bis(bipyridine) sulfoxide complexes,” Inorganic Chemistry, vol. 39, no. 2, pp. 317–324, 2000. [3] T. Suzuki, T. Kuchiyama, S. Kishi, S. Kaizaki, H. D. Takagi, and M. Kato, “Ruthenium(II) complexes containing 8(dimethylphosphino)quinoline (Me2 Pqn): preparation, crystal structures, and electrochemical and spectroscopic properties of [Ru(bpy or phen)3−𝑛 (Me2 Pqn)n] (PF6 )2 (bpy = 2,2󸀠 -bipyridine; phen = 1,10-phenanthroline; n = 1, 2, or 3),” Inorganic Chemistry, vol. 42, no. 3, pp. 785–795, 2003. [4] J.-P. Sauvage, J.-P. Collin, J.-C. Chambron et al., “Ruthenium(II) and osmium(II) bis(terpyridine) complexes in covalentlylinked multicomponent systems: synthesis, electrochemical behavior, absorption spectra, and photochemical and photophysical properties,” Chemical Reviews, vol. 94, no. 4, pp. 993– 1019, 1994. [5] A. O. Adeloye, “Synthesis, photophysical and electrochemical properties of a mixed bipyridyl-phenanthrolyl ligand Ru(II) heteroleptic complex having trans-2-Methyl-2-butenoic acid functionalities,” Molecules, vol. 16, no. 10, pp. 8353–8367, 2011. [6] M. Galletta, F. Puntoriero, S. Campagna et al., “Absorption spectra, photophysical properties, and redox behavior of ruthenium(II) polypyridine complexes containing accessory dipyrromethene-BF2 chromophores,” Journal of Physical Chemistry A, vol. 110, no. 13, pp. 4348–4358, 2006. [7] A. Juris, V. Balzani, F. Barigelletti, S. Campagna, P. Belser, and A. von Zelewsky, “Ru(II) polypyridine complexes: photophysics, photochemistry, eletrochemistry, and chemiluminescence,” Coordination Chemistry Reviews, vol. 84, pp. 85–277, 1988. [8] S. P. Foxon, C. Green, M. G. Walker et al., “Synthesis, characterization, and DNA binding properties of ruthenium(II) complexes containing the redox active ligand benzo[i]dipyrido[3,2a: 2󸀠 ,3󸀠 -c]phenazine-11,16-quinone,” Inorganic Chemistry, vol. 51, no. 1, pp. 463–471, 2012. [9] M. S. Deshpande, A. A. Kumbhar, A. S. Kumbhar et al., “Ruthenium(II) complexes of bipyridine-glycoluril and their


[10]

[11]

[12]

[13]

[14]

[15]

[16]

[17]

[18]

[19]

[20]

[21]

[22]

[23]

[24]

interactions with DNA,” Bioconjugate Chemistry, vol. 20, no. 3, pp. 447–459, 2009. L. N. Suvarapu, Y. K. Seo, S. O. Baek, and V. R. Ammireddy, “Review on analytical and biological applications of hydrazones and their metal complexes,” E-Journal of Chemistry, vol. 9, no. 3, pp. 1288–1304, 2012. L. Mitu, M. Ilis, N. Raman, M. Imran, and S. Ravichandran, “Transition metal complexes of isonicotinoyl-hydrazone-4diphenylaminobenzaldehyde: synthesis, characterization and antimicrobial studies,” E-Journal of Chemistry, vol. 9, no. 1, pp. 365–372, 2012. R. K. Mohapatra, U. K. Mishra, S. K. Mishra, A. Mahapatra, and D. C. Dash, “Synthesis and characterization of transition metal complexes with benzimidazolyl-2-hydrazones of oanisaldehyde and furfural,” Journal of the Korean Chemical Society, vol. 55, no. 6, pp. 926–931, 2011. R. K. Mohapatra, M. P. Dash, S. B. Joshi et al., “Synthesis and spectral characterization of transition metal complexes with benzothiazolyl-2-hydrazones of salicylidene acetone and salicylidene acetophenone,” Acta Chimica & Pharmaceutica Indica, vol. 2, p. 156, 2012. C. Anitha, S. Sumathi, P. Tharmaraj et al., “Synthesis, characterization, and biological activity of some transition metal complexes derived from novel hydrazone azo schiff base ligand,” International Journal of Inorganic Chemistry, vol. 2011, Article ID 493942, 8 pages, 2011. M. Cˇalinescu, E. Ion, and A.-M. Stadler, “Studies on nickel(II) complex compounds with 2-benzothiazolyl hydrazones,” Revue Roumaine de Chimie, vol. 53, no. 10, pp. 903–909, 2008. B. P. Sullivan, D. J. Salmon, and T. J. Meyer, “Mixed phosphine 2,2󸀠 -bipyridine complexes of ruthenium,” Inorganic Chemistry, vol. 17, no. 12, pp. 3334–3341, 1978. K. Nakamoto, Infrared and Raman Spectra of Inorganic and Coordination Compounds, John Wiley & Sons, New York, NY, USA, 4th edition, 1986. M. R. Maurya, N. Agarwal, and S. Khurana, “Synthesis and characterization of metal complexes of methylene bridged hexadentate tetraanionic ligands,” Indian Journal of Chemistry A, vol. 39, no. 10, pp. 1093–1097, 2000. Z. H. Peng, X. M. Ren, C. J. Fang, B. G. Zhang, and J. T. Suen, “Synthesis and spectroscopic characterization of transition metal complexes of maleionitriledithiolene and 1,10phenanthroline,” Chinese Chemical Letters, vol. 10, no. 3, pp. 263–266, 1999. N. Raman and S. Sobha, “Synthesis, characterization, DNA interaction and antimicrobial screening of isatin-based polypyridyl mixed-ligand Cu(II) and Zn(II) complexes,” Journal of the Serbian Chemical Society, vol. 75, no. 6, pp. 773–788, 2010. R. Prajapati, V. K. Yadav, S. K. Dubey, B. Durham, and L. Mishra, “Reactivity of metal (ZnII, RuII)-2,2󸀠 -bipyridyl with some bifunctional ligands,” Indian Journal of Chemistry A, vol. 47, no. 12, pp. 1780–1786, 2008. M. M. H. Khalil, E. H. Ismail, G. G. Mohamed, E. M. Zayed, and A. Badr, “Synthesis and characterization of a novel schiff base metal complexes and their application in determination of iron in different types of natural water,” Open Journal of Inorganic Chemistry, vol. 2, no. 2, pp. 13–21, 2012. M. S. Nair, D. Arish, and R. S. Joseyphus, “Synthesis, characterization, antifungal, antibacterial and DNA cleavage studies of some heterocyclic Schiff base metal complexes,” Journal of Saudi Chemical Society, vol. 16, no. 1, pp. 83–88, 2012. H. N. Aliyu and U. Sani, “Synthesis, characterization and biological activity of manganese(II), iron(II), cobalt(II), nickel(II)

7

[25]

[26]

[27]

[28]

[29]

[30]

[31]

[32] [33] [34]

[35] [36]

[37]

[38]

[39]

and copper(II) schiff base complexes against multidrug resistant bacterial and fungal pathogens,” International Research Journal of Pharmacy and Pharmacology, vol. 2, p. 40, 2012. W. H. Hegazy and M. Gaafar, “Synthesis, characterization and antibacterial activities of new Pd(II) and Pt(IV) complexes of some unsymmetrical tetradentate schiff bases,” American Chemical Science Journal, vol. 2, no. 3, p. 86, 2012. R. M. Silverstine, G. C. Bausler, T. C. Morill et al., Spectroscopic Identification of Organic Compounds, John Wiley & Sons, New York, NY, USA, 5th edition, 1991. T. Sofia, B. Mahdi, N. Hossein et al., “Synthesis, characterization, and biological studies of new ruthenium polypyridine complexes containing noninnocent ligand,” ISRN Inorganic Chemistry, vol. 2013, Article ID 623962, 6 pages, 2013. M. S. Deshpande and A. S. Kumbhar, “Mixed-ligand complexes of ruthenium(II) incorporating a diazo ligand: synthesis, characterization and DNA binding,” Journal of Chemical Sciences, vol. 117, no. 2, pp. 153–159, 2005. J. Karolin, L. B.-A. Johansson, L. Strandberg, and T. Ny, “Fluorescence and absorption spectroscopic properties of dipyrrometheneboron difluoride (BODIPY) derivatives in liquids, lipid membranes, and proteins,” Journal of the American Chemical Society, vol. 116, no. 17, pp. 7801–7806, 1994. D. Arish and M. S. Nair, “Synthesis, characterization and biological studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes with pyrral-l-histidinate,” Arabian Journal of Chemistry, vol. 5, no. 2, pp. 179–186, 2012. K. K.-W. Lo, W.-K. Hui, C.-K. Chung, K. H.-K. Tsang, T. K.-M. Lee, and D. C.-M. Ng, “Luminescent transition metal polypyridine biotin complexes,” Journal of the Chinese Chemical Society, vol. 53, no. 1, pp. 53–65, 2006. M. Montalti, A. Credi, L. Prodi et al., Handbook of Photochemistry, CRC Press, Boca Raton, Fla, USA, 3rd edition, 2006. M. Klessinger and J. Michl, Excited States and Photochemistry of Organic Molecules, Wiley-VCH, New York, NY, USA, 1995. G. A. Crosby, “Spectroscopic investigations of excited states of transition-metal complexes,” Accounts of Chemical Research, vol. 8, no. 7, pp. 231–238, 1975. T. J. Meyer, “Chemical approaches to artificial photosynthesis,” Accounts of Chemical Research, vol. 22, no. 5, pp. 163–170, 1989. K. F. Freed and J. Jortner, “Multiphonon processes in the nonradiative decay of large molecules,” The Journal of Chemical Physics, vol. 52, no. 12, pp. 6272–6291, 1970. L.-N. Ji, X.-H. Zou, and J.-G. Liu, “Shape- and enantioselective interaction of Ru(II)/Co(III) polypyridyl complexes with DNA,” Coordination Chemistry Reviews, vol. 216-217, pp. 513–536, 2001. M. M. A. Sekkina and M. G. A. El-Azm, “Thermochemical analyses of solid isonicotinic hydrazide transition metal complexes,” Thermochimica Acta, vol. 79, pp. 47–53, 1984. J. Y. Lu, M. A. Lawandy, and J. Li, “A new type of twodimensional metal coordination systems: Hydrothermal synthesis and properties of the first oxalate-BPY mixed-ligand framework∞2[M(ox)(bpy)] (M = Fe(II), Co(II), Ni(II), Zn(II); ox = (𝐶2 𝑂4 )2− ; bpy = 4,4󸀠 -bipyridine),” Inorganic Chemistry, vol. 38, no. 11, pp. 2695–2704, 1999.

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