Highly symmetrical polyfluorinated porphyrazines

Journal of Fluorine Chemistry 149 (2013) 65–71

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Highly symmetrical polyfluorinated porphyrazines Ergu¨n Gonca 1,* Fatih University, Department of Chemistry, TR 34500 Bu¨yu¨kc¸ekmece, I˙stanbul, Turkey

A R T I C L E I N F O

A B S T R A C T

Article history: Received 16 November 2012 Received in revised form 13 February 2013 Accepted 13 February 2013 Available online 19 February 2013

By cyclotetramerization of 2,3-bis[2-fluoro-5-(trifluoromethyl)benzylthio] maleonitrile in the presence of magnesium butanolate, magnesium porphyrazinate carrying eight (2-fluoro-5-(trifluoromethyl)benzylthio) functional groups on the periphery positions has been synthesized. Conversion of the magnesium porphyrazinate into the metal-free derivative was achieved by treatment with trifluoroacetic acid. Further reaction of this product with different metal (II) acetates have led to the metallo porphyrazines. Then, chloro-octakis [2-fluoro-5-(trifluoromethyl)benzylthio] porphyrazinato iron (III) (FePzCl) was prepared by the reaction of metal-free porphyrazine with iron (II) acetate and further treatment with HCl solution. The monomeric bisaxial complex FePz(py)2 as well as the bridged complex [FePz(pyz)]n were formed as stable complexes by reacting FePzCl with pyridine or pyrazine, respectively. These novel complexes were characterized by elemental analysis, together with FT-IR, 1H NMR, 13C NMR, 19F NMR, UV–vis and mass spectral data. ß 2013 Elsevier B.V. All rights reserved.

Keywords: 2-Fluoro-5-(trifluoromethyl)benzyl bromide Pyridine Pyrazine Shish kebab type olygomer Bisaxial complex 19 F NMR spectroscopy

1. Introduction Tetraazaporphyrins, or porphyrazines as they are more commonly known, are part of a family of aromatic, tetrapyrrolic ring systems that can be divided into two distinct categories, namely porphyrins and tetraazaporphyrins, in which meso nitrogen atoms replace the methine groups. The latter can be further divided into porphyrazines (Pz), and phthalocyanines (Pc), which contain benzenoid rings fused to the macrocyclic periphery. Due to their unique electronic and optical properties, potential applications of tetraazaporphyrins include biomedical agents, chemical sensors, liquid crystals, non-linear optics, Langmuir– Blodgett films, and ladder polymers, to name but a few [1–8]. In recent years, porphyrazines that bear a range of carbon and heteroatomic substituents fused directly to the macrocyclic periphery have gained increasing attention. This is due to the strong correlation between the nature of the substituent, and the electronic and optical properties of the macrocyclic ring system, coupled with the relative ease of their synthetic preparation. In comparison to the other family members, analogous derivatives are virtually inaccessible for the porphyrins, and direct fusion of heteroatomic substituents onto the porphyrazine b-positions results in a pronounced effect compared with the substitution of an equivalent group onto the benzenoid rings of the

* Tel.: +90 212 8663300/2066; fax: +90 212 866 34 02. E-mail address: [email protected] 1 Tel.: +90 212 8662066. 0022-1139/$ – see front matter ß 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jfluchem.2013.02.012

phthalocyanines. The porphyrazines also often display a vastly increased solubility in organic solvents compared with their phthalocyanine counterparts. Thus, porphyrazines maintain a unique position in the family of tetrapyrrolic macrocycles, and their straightforward synthesis, coupled with their tuneable electronic and optical properties, renders them exciting candidates for a whole range of applications [9–14]. The addition of fluorine atoms to biologically active compounds modulates their physical–chemical and pharmacological properties [15]. These conversions allow their use in many therapeutic studies, including treatment of bacterial and fungal infections, cancer, cardiovascular and central nervous system diseases [16,17]. Many porphyrinoids having peripheral fluorine atoms and groups show potential for photodynamic therapy due to their enhanced stability, high level of singlet oxygen production, lipophilicity, and selective accumulation in tumor cells [18–21]. However, it has been demonstrated that porphyrins with fluorine atoms can be applied in in vivo imaging using 19F NMR [19,22]. Recently, we synthesized and characterized some fluorinated tetrapyrroles, such as porphyrazines and phthalocyanines, which display potential applications in biology and medicine [23–30]. In our previous paper, we have reported the synthesis, structural and spectral properties of symmetric metallo-porphyrazines [23]. In this study, our aim has been to design new molecules with polyfluoro-substituents, enhancing their solubility in common organic solvents. We report the synthesis, and characterization of new readily soluble metallo-porphyrazines with up to 32 fluorine-containing substituents on the periphery for the first time, and we also report on the effects of the substituents

E. Gonca / Journal of Fluorine Chemistry 149 (2013) 65–71

66

F3C

F3C

NC

S

SNa

Br

(ii)

F3C NC

F

F

(i)

+

CN

S

SNa

CN

F

3

(iii)

(iv)

4

5-7

Scheme 1. (i) MeOH; (ii) Mg turnings, I2, n-BuOH; (iii) CF3CO2H; (iv) EtOH and Co(OAc)2, Cu(OAc)2, or Zn(OAc)2.

been obtained from 2,3-dinitrile derivative (1) with desired substituents. Alkylation of 1 with 2-fluoro-5-(trifluoromethyl)benzyl bromide in MeOH gave 2,3-bis[2-fluoro-5-(trifluoromethyl)benzylthio]maleonitrile (2) which was in cis-form and easily soluble in CHCl3, CH2Cl2, and acetone. The orange colored product, 2, was obtained in 84% yield (Scheme 1). Cyclic tetramerization of 2 can be performed by several ways. However, the yield of the reaction is strongly dependent on the substituents on the benzene rings and the central metal atom. The presence of bulky electron-donating S-groups is expected to enhance the chemical stability and optical properties of porphyrazines [31]. Cyclotetramerization of 2 into octakis(2-fluoro-5-(trifluoromethyl)benzylthio) porphyrazinato magnesium (3) was realized by making use of the template effect of magnesium ions. The optimum condition was to accomplish the reaction in n-BuOH at reflux temperature for 12 h (Scheme 1) [32–34]. 3 was very soluble in most of the common solvents except MeOH and EtOH (Fig. 1). The conversion of 3 into to the metal-free porphyrazine (4) was

on the spectroscopic properties of the porphyrazine complexes in different solvents. In addition, we report novel soluble iron porphyrazine derivatives with eight 2-fluoro-5-(trifluoromethyl)benzylthio substituents appending to the periphery positions. Chloro {octakis [2-fluoro-5-(trifluoromethyl)benzylthio] porphyrazinato} iron (III) (8) was prepared by the reaction of metal-free porphyrazine with iron (II) acetate and further treatment with HCl solution. The monomeric bisaxial complex [FePz(py)2] (9) as well as the bridged complex [FePz(pyz)]n (10) were formed as stable complexes by reacting 8 with pyridine or pyrazine, respectively. By using different spectroscopic methods such as elemental analysis, FT-IR, 1H NMR, 13C NMR, 19F NMR, UV–vis and mass spectrometry, novel compounds have been characterized. 2. Results and discussion The synthesis of the novel compounds (2-10) is shown in Schemes 1 and 2. Peripherally substituted porphyrazines have F3C

F3C

CF3 F

F3C

CF3

F F3C

CF3

S

S

N S

S

N

N N

F

M N

S

F

N

S

N

S

S

S

F3C

F

F

CF3

CF3

Cl

Fe

F

F

N

NH

i

N N

S

S

F

N

F3C

CF3

S

S

N F

F

F

F

N F

N H

S

N

F3C

S

S F

F3C

H2Pz (4)

F

FePzCl (8) ii [FePz(py)2] (9)

iii [FePz(pyz)]n (10)

Scheme 2. Synthesis route to new compounds: (i) Fe(OAc)2, HOAc, HCl; (ii) pyridine; (iii) pyrazine.

CF3

CF3

E. Gonca / Journal of Fluorine Chemistry 149 (2013) 65–71

F3C

F3C

CF3

F

F

N

F3C

CF3

S

S

S

S N

M

F

N

S

N F3C

S

F

F3C

N

CF3

S

CF3

F

CF3

N

CF3

F

F

S

F

F3C

S

S

NH

S

F

N

Fe N

S

F

N

S

N

HN N

F

CF3

S

N

S

F

N

F3C

S

F

N

N

CF3

F

F

F3C

N F

67

Fig. 2. Bis(pyridine){octakis [2-fluoro-5-(trifluoromethyl)benzylthio]porphyrazinato} iron (II) [FePz(py)2] (9).

M = Mg (3); 2H (4); Co (5); Cu (6); Zn (7). 682 nm as a single intense absorption) [38,39] to C4v symmetry, resulting in an intense band at 588 nm together with two others at 544 and 680 nm [37]. This Q band absorption was appearing as two peaks at 622 and 678 nm in the case of metal-free porphyrazine with D2h symmetry [38,39]. It is not factual to reduce 8 to the divalent state in non-donating solvents, but the behavior of 8 with pyridine at ambient temperature results in the octahedrally coordinated FePz(py)2 complex (9) (Fig. 2) [35]. Its formation may be efficiently followed by the differences in the color of the solution and also approved by the electronic spectrum, which encloses a single and intense Q band absorption at 592 nm, typical of D4h symmetry. Tetrapyrroles having transition metal ion, e.g. iron (II), in the centre are of important property while they form ‘‘shish kebab’’ type axially coordinated bridged complexes with bidentate coordinating ligands. 8 can be easily reduced to axially coordinated 9 in the presence of ligands such as pyridine. We have prepared bridged systems with pyz and an axially coordinated monomer with pyridine (Scheme 2). While pyridine can react with 8 in benzene solutions, we accomplish the reaction with pyz only in melted excess ligand and the product is a bridged system (not bisaxially coordinated monomer) (Fig. 3).

Fig. 1. Octakis [2-fluoro-5-(trifluoromethyl)benzylthio] substituted porphyrazines (3-7).

achieved by the treatment with CF3CO2H. The spectroscopic data have clearly indicated the change of the structure from 3 to 4. Further reaction of 4 with cobalt (II) acetate, copper (II) acetate, and zinc (II) acetate has led to the metallo porphyrazines (M = Co, Cu, Zn) (5-7) (Fig. 1). Iron insertion into 4 was carried out in acetic acid using anhydrous iron (II) acetate as the metal salt (Scheme 2) [35,36]. Although the reaction was carried out under inert atmosphere, trace amounts of oxygen led to Fe (III) derivatives. Further exposure to air was almost inevitable during the work-up procedures, so the product was treated with dilute HCl solution in order to convert all of the trivalent iron products into FePzCl. The band at 1089 cm 1 in the FT-IR spectrum of 8 can be assigned to the contribution of axial ligands to CN-skeleton vibrations as encountered in octaphenyltetraazaporphyrins [37]. Another consequence of the presence of the axial chloride ligand is the changes occurring in the Q-band absorption from an MPz derivative of D4h symmetry (e.g. MgPz where Q band is at F3C

F3C

S

F3C

CF3

F

F

F3C

CF3

S

F

F

S

S

NH N N

Fe

F

N

F

S

Fe

CF3

F3C

N

N

F

Fe

F F

S

F

S N

F3C

S

CF3

CF3

F

N

N HN

S

F

S

NH N

S S

CF3

F

N

N

F3C

CF3

S

S

F

F

N

N HN

S

S S

F3C

N

N

F

S

NH N

F

N

F3C

S N

S

F

F

N

N HN

S

F3C

N

S

F

CF3

F

F CF3

S

N

F3C

CF3

F3C

F

Fig. 3. m-Pyrazine{octakis [2-fluoro-5-(trifluoromethyl)benzylthio]porphyrazinato} iron (II) [FePz(pyz)]n (10).

S

CF3

F CF3

E. Gonca / Journal of Fluorine Chemistry 149 (2013) 65–71

68

All new compounds were characterized by using many spectroscopic techniques such as FT-IR, 1H NMR, 13C NMR, 19F NMR, UV–vis, mass and elemental analysis. The spectroscopic data of desired products were in accordance with the assigned structures. Elemental analyses agree closely with the values calculated for (2-10). In the FT-IR spectrum of 2 stretching vibration of CBN is observed at 2222 cm 1, the aromatic and aliphatic C–H peaks are around 2870-3070 cm 1, aromatic C5 5C stretching vibrations are at 1650 cm 1 and C–F stretching vibrations are around 13521116 cm 1. After the conversion of 2 into 3, the sharp CBN vibration around 2222 cm 1 disappeared. The N–H stretching absorption of the inner core of 4 was observed around 3310 cm 1. FT-IR spectra of all porphyrazines derivatives (3-10) showed the aromatic C–H stretching vibration peaks around 3075-3030 cm 1, the aliphatic C–H stretching vibration peaks around 29752850 cm 1, the aromatic C5 5C peaks around 1675-1650 cm 1, and C–F stretching vibrations are around 1350-1120 cm 1. In the FT-IR spectrum of 9, the newly appearing band at 1588 cm 1 and 1225 cm 1 are likely to be due to the breathing mode of axial pyridine groups. The NMR investigations of porphyrazines have provided the characteristic chemical shifts for the structures expected. In the 1H NMR spectra of 2,3-bis(2-fluoro-5-(trifluoromethyl)benzylthio)maleonitrile (2) four types of protons are clearly seen: Three dd around 7.68-7.35 ppm corresponding to aromatic protons, a singlet at 4.66 ppm belonging to S–CH2. The NH protons in the inner core of the metal-free porphyrazine (4) are also very well characterized by the 1H NMR which shows a peak at d = 1.25 ppm as a result of the 18 p-electron system of the porphyrazine ring [23–30,40,41]. The 1H NMR spectra of 9 and 10 indicate an octahedrally coordinated Fe (II) complex. The chemical shift values of the axially coordinated ligands have been extensively affected by the 18-p electrons of the porphyrazine core, i.e. the peaks at 8.59, 7.75 and 7.38 ppm in free pyridine have been shifted to 6.84, 4.75 and 2.35 ppm, respectively, after binding axially to form FePz(py)2. Similarly, there is only a single peak at 2.26 ppm for pyrazine protons in the bridged structure [FePz(pyz)]n [42–44]. In the 13C NMR spectra of porphyrazines 3, 4 and 6, ten different single chemical shifts for carbon atoms are clearly seen. 19F NMR spectroscopy has been a very useful technique for investigating the fluorinated compound. 19F NMR spectrum of 3 showed two different peaks at 144.8 ppm (o-fluoro) and 63.40 ppm. In addition to these verifying results for the structures, the mass spectra of compounds (3-9) gave the characteristic molecular ion peaks at m/z: 2002.9 [M]+, 1979.2 [M]+, 2036.3 [M]+, 2041.8 [M]+, 2043.8 [M]+, 2069.8[M]+, and 2191.1 [M]+ respectively, confirming the proposed structures. UV–vis spectral data of 3, 5-7 in solvents of different polarity (acetone, chloroform, THF and dichloromethane) are given in Table 1 UV–vis data for the porphyrazines (3, 5-7) in different solvents.a Compound

(CH3)2CO

CHCl3

THF

CH2Cl2

3

385 (4.96) 683 (4.95)

3.84 (4.94) 682 (4.93)

3.80 (4.93) 677 (4.93)

383 (4.92) 681 (4.91)

5

340 (4.73) 667 (4.80)

343 (4.70) 670 (4.77)

341 (4.69) 668 (4.76)

346 (4.65) 673 (4.73)

6

353 (4.96) 684 (5.01)

356 (4.92) 687 (4.99)

358 (4.92) 689 (4.98)

359 (4.90) 690 (4.96)

7

341 (4.91) 680 (4.96)

346 (4.89) 685 (4.93)

345 (4.87) 686 (4.92)

347 (4.85) 687 (4.90)

a

lmax/nm (log e/dm3 mol

1

cm

1

).

Fig. 4. UV–vis spectrum of 8 in chloroform.

Fig. 5. UV–vis spectra of 9 in various solvents.

Table 1. There is almost no difference with respect to the changes in the nature of the solvent. The Q bands, appearing at 592 and 625 nm in the UV–visible spectrum of FePz(py)2 (9) or [FePz(pyz)]n (10), confirm the coordination of the pyridine and pyrazine ligands to the metal ion. UV–vis spectrum of 8 in chloroform is shown in Fig. 4. UV–vis spectra of 9 in various solvents are shown in Fig. 5. When a bidentate ligand such as pyrazine is used instead of pyridine, similar changes occur in the oxidation state of the metal ion. In addition, bidentate ligands form a bridge between the metal centers and form a shish kebab type olygomer [45,46]. In the electronic spectrum of 10, the Q band absorption at 625 nm has been shifted to longer wavelength (ca. 33 nm) when compared with the monomeric structure (9) obtained with pyridine. There is also a shoulder around 710 nm in the electronic spectra after oligomer formation. 3. Conclusions In this present work, we have described the synthesis, the spectral properties and the preparation of novel soluble polyfluorinated porphyrazine derivatives. The monomeric bisaxial complex FePz(py)2 as well as the bridged complex, shish kebab type olygomer, [FePz(pyz)]n were formed as stable complexes by

E. Gonca / Journal of Fluorine Chemistry 149 (2013) 65–71

reacting FePzCl with pyridine or pyrazine, respectively. Solubility of metallo porphyrazines in common solvents is enhanced. Consequently, we might conclude that the Fe(II)Pz macrocycle reacts in excess liquid pyrazine to form exclusively a polymeric compound as is the case for most tetraaza annulenes. 4. Experimental IR spectra were recorded on a Perkin Elmer Spectrum One FT-IR (ATR sampling accessory) spectrophotometer, electronic spectra on a Unicam UV2 spectrophotometer. 1H NMR, 13C NMR and 19F NMR spectra, were taken in CDCl3 solutions at 400.000, 100.577 and 376.308 MHz, respectively, recorded on a Bruker Ultra Shield Plus 400 MHz spectrometer. Chemical shifts refer to TMS (1H NMR and 13C NMR) and fluorotrichloromethane (19F NMR) as the internal standards. Mass spectra were recorded on a Bruker Daltonics Micro-TOF and MALDI-TOF mass spectrometer using the electrospray ionisation (ESI) method. The instrument was operated in positive ion mode. Elemental analyses were recorded on a Thermo Scientific 2000 instrument. All starting materials were purchased from major suppliers and used without any further purification. The homogeneity of the products was tested in each step by TLC. The disodium salt of dithiomaleonitrile (1) was prepared according to the previously reported procedures [47]. 4.1. Synthesis of 2,3-bis[2-fluoro-5(trifluoromethyl)benzylthio]maleonitrile (2) Disodium salt of dithiomaleonitrile (1) (1.12 g, 6.00 mmol) was mixed with 2-fluoro-5-(trifluoromethyl)benzyl bromide (3.86 g, 15.0 mmol) in methanol (50 mL) and refluxed under nitrogen for about 18 h. After evaporation of MeOH, the remaining oil product was treated with CHCl3 to remove insoluble salts by filtration. The CHCl3 solution was extracted several times with 15% Na2SO4 solution and then dried over anhydrous Na2SO4 overnight. When CHCl3 was evaporated the colored product was dissolved in a minimum amount of chloroform and then added drop wise into cold n-hexane to precipitate the product, which was filtered off and dried in vacuum. The orange colored product was very soluble in CHCl3, CH2Cl2, and acetone, but insoluble in n-hexane. Yield: 1.30 g (84%). FT-IR, nmax/cm 1: 3070-3035 (CH, aromatic), 2988-2870 (CH, aliphatic), 2222 (CBN), 1665, 1650 (C5 5C, aromatic), 1502, 1416, 1352, 1305, 1277, 1184, 1116, 1057, 903, 848, 707, 683, 565. 1 H NMR (d, ppm): 7.68 (dd, 2H, Ar–H), 7.46 (dd, 2H, Ar–H), 7.35 (dd, 2H, Ar–H), 4.66 (s, 4H, S–CH2). 13C NMR (d, ppm): 33.2, 113.7, 115.4, 116.0, 124.2, 125.3, 126.4, 127.2, 127.4, 163.7. 19F NMR (d, ppm): 144.5 (o-fluoro), 63.44. MS (ESI) m/z: 494.9 [M]+. Calcd. for C20H10N2S2F8: C 48.59; H 2.04; N 5.67; S 12.97. Found: C 48.70; H 2.11; N 5.56; S 12.85. 4.2. {2,3,7,8,12,13,17,18-Octakis[2-fluoro-5(trifluoromethyl)benzylthio] porphyrazinato} Mg(II) (3) Mg turnings (6 mg, 0.25 mmol) and a small I2 crystal were refluxed in n-BuOH (20 mL) for about 8 h to obtain Mg(BuO)2. 2,3bis(2-fluoro-5-(trifluoromethyl)benzylthio) maleonitrile (2) (247 mg, 0.50 mmol) was added to this solution and the mixture was refluxed for about 12 h. The colored product was filtered, washed with ethanol and water and dried in a vacuum. The crude product was dissolved in CHCl3 and filtered. The CHCl3 solution was dried over anhydrous Na2SO4. When CHCl3 was evaporated, the dark green colored product was obtained. Purification of the product was accomplished by column chromatography with silica gel using MeOH/CHCl3 (1:50) as eluent. 3 was soluble in CHCl3, CH2Cl2, acetone and THF, but insoluble in n-hexane. Yield: 205 mg

69

(82%). FT-IR, nmax/cm 1: 3074-3038 (CH, aromatic), 2956-2864 (CH, aliphatic), 1662 (C5 5C, aromatic), 1510, 1410, 1345, 1308, 1272, 1188, 1120, 1060, 908, 842, 712, 688, 569. UV–vis (CHCl3) (1  10 5 M) lmax (nm) (log e/dm3 mol 1 cm 1): 384 (4.94), 682 (4.93). 1H NMR (d, ppm): 7.66 (dd, 8H, Ar–H), 7.48 (dd, 8H, Ar–H), 7.32 (dd, 8H, Ar–H), 4.62 (s, 16H, S–CH2). 13C NMR (d, ppm): 33.4, 113.9, 115.2, 116.3, 124.4, 125.5, 126.2, 127.4, 127.8, 163.4. 19F NMR (d, ppm): 144.8 (o-fluoro), 63.40. MS (ESI) m/z: 2002.9 [M]+. Calcd. for C80H40N8S8F32Mg: C 48.00; H 2.01; N 5.60; S 12.81. Found: C 48.12; H 2.12; N 5.48; S 12.70. 4.3. {2,3,7,8,12,13,17,18-Octakis[2-fluoro-5(trifluoromethyl)benzylthio] H21, H23 porphyrazine} (4) 3 (100 mg, 0.05 mmol) was dissolved in the minimum amount of CF3CO2H (4 mL) and stirred for 3 h at room temperature. When the reaction mixture was added to ice drop by drop and neutralized with 25% NH3 solution, precipitation occurred and it was filtered. The precipitate was extracted into the CHCl3 and the CHCl3 solution was extracted with water twice. After drying over anhydrous Na2SO4, the solvent was evaporated to obtain a violet colored metal-free porphyrazine. 4 was obtained by column chromatography (SiO2, MeOH:CHCl3, 1:30, v/v). Yield: 67 mg (68%). FT-IR, nmax/cm 1: 3310 (N–H), 3075-3032 (CH, aromatic), 2938-2855 (CH, aliphatic), 1668 (C5 5C, aromatic), 1508, 1410, 1350, 1308, 1275, 1182, 1122, 1064, 902, 842, 702, 686, 580. UV– vis (CHCl3) (1  10 5 M) lmax (nm) (log e/dm3 mol 1 cm 1): 350 (4.82), 622 (4.24), 678 (4.32). 1H NMR (d, ppm): 7.64 (dd, 8H, Ar– H), 7.46 (dd, 8H, Ar–H), 7.34 (dd, 8H, Ar–H), 4.64 (s, 16H, S–CH2), 1.25 (br s, 2H, NH). 13C NMR (d, ppm): 33.5, 113.6, 115.0, 116.5, 124.6, 125.2, 126.4, 127.1, 127.5, 163.6. 19F NMR (d, ppm): 144.6 (o-fluoro), 63.42. MS (ESI) m/z: 1979.2 [M]+. Calcd. for C80H42N8S8F32: C 48.54; H 2.14; N 5.66; S 12.96. Found: C 48.41; H 2.25; N 5.52; S 12.82. 4.4. General procedure for metallo porphyrazines (5-7) 4 (99 mg, 0.05 mmol) in CHCl3 (10 mL) was stirred with the metal salt [Co(OAc)2 (89 mg, 0.5 mmol), Cu(OAc)2 (91 mg, 0.5 mmol), or Zn(OAc)2 (92 mg, 0.5 mmol)] in EtOH (15 mL) and refluxed under nitrogen for about 6 h. Then, the precipitate composed of the crude product and the excess metal salt were filtered. The precipitate was treated with CHCl3 and the insoluble metal salts were removed by filtration. The filtrate was reduced to minimum volume under reduced pressure and then added into nhexane (150 mL) drop by drop to realize the precipitation. Finally, pure porphyrazine derivatives (5-7) were obtained by column chromatography (SiO2, MeOH:CHCl3, 1:50, v/v). 4.4.1. {2,3,7,8,12,13,17,18-Octakis[2-fluoro-5(trifluoromethyl)benzylthio] porphyrazinato} Co(II) (5) Yield: 61 mg (60%). FT-IR, nmax/cm 1: 3072-3032 (CH, aromatic), 2946-2860 (CH, aliphatic), 1666 (C5 5C, aromatic), 1504, 1412, 1342, 1312, 1278, 1184, 1124, 1062, 904, 846, 716, 684, 565. UV– vis (CHCl3) (1  10 5 M) lmax (nm) (log e/dm3 mol 1 cm 1): 343 (4.70), 670 (4.77). MS (ESI) m/z: 2036.3 [M]+. Calcd. for C80H40N8S8F32Co: C 47.18; H 1.98; N 5.50; S 12.60. Found: C 47.29; H 1.89; N 5.62; S 12.47. 4.4.2. {2,3,7,8,12,13,17,18-Octakis[2-fluoro-5(trifluoromethyl)benzylthio] porphyrazinato} Cu(II) (6) Yield: 49 mg (48%). FT-IR, nmax/cm 1: 3070-3035 (CH, aromatic), 2926-2855 (CH, aliphatic), 1660 (C5 5C, aromatic), 1502, 1410, 1344, 1315, 1275, 1180, 1128, 1060, 908, 842, 718, 688, 560. UV– vis (CHCl3) (1  10 5 M) lmax (nm) (log e/dm3 mol 1 cm 1): 356 (4.92), 687 (4.99). MS (ESI) m/z: 2041.8 [M]+. Calcd. for

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C80H40N8S8F32Cu: C 47.07; H 1.98; N 5.49; S 12.57. Found: C 47.17; H 2.09; N 5.38; S 12.69. 4.4.3. {2,3,7,8,12,13,17,18-Octakis[2-fluoro-5(trifluoromethyl)benzylthio] porphyrazinato} Zn(II) (7) Yield: 65 mg (64%). FT-IR, nmax/cm 1: 3075-3030 (CH, aromatic), 2938-2854 (CH, aliphatic), 1664 (C5 5C, aromatic), 1508, 1410, 1344, 1314, 1276, 1188, 1126, 1065, 910, 845, 712, 690, 562. UV– vis (CHCl3) (1  10 5 M) lmax (nm) (log e/dm3 mol 1 cm 1): 346 (4.89), 685 (4.93). 1H NMR (d, ppm): 7.68 (dd, 8H, Ar–H), 7.44 (dd, 8H, Ar–H), 7.36 (dd, 8H, Ar–H), 4.68 (s, 16H, S–CH2). 13C NMR (d, ppm): 33.2, 113.7, 115.4, 116.5, 124.7, 125.3, 126.4, 127.4, 127.6, 163.6. 19F NMR (d, ppm): 144.6 (o-fluoro), 63.44. MS (ESI) m/z: 043.8 [M]+. Calcd. for C80H40N8S8F32Zn: C 47.03; H 1.97; N 5.48; S 12.56. Found: C 47.15; H 1.85; N 5.60; S 12.44. 4.5. Chloro {octakis [2-fluoro-5-(trifluoromethyl)benzylthio] porphyrazinato} iron (III) (FePzCl) (8) A mixture of 4 (95 mg, 0.0478 mmol) and Fe(OAc)2 (416 mg, 2.39 mmol) in HOAc (20 mL) was heated at 120 8C for 24 h under nitrogen. The reaction was monitored continuously for the presence of metal-free porphyrazine by UV–vis spectroscopy. After completion of the reaction, the mixture was filtered and HOAc was evaporated under reduced pressure. The residue was dissolved in CHCl3 (50 mL) and then extracted several times with 1 M, 100 mL HCl until no yellowish color of ferric salts was present in the aqueous phase. The CHCl3 solution was washed twice with water and dried over Na2SO4. When the solvent was evaporated, a green product was obtained. Finally, the pure porphyrazine was obtained by chromatography on silica gel using MeOH/CHCl3 (1:50) mixture as eluent. The product (8) was soluble in CHCl3, CH2Cl2, and acetone, but insoluble in n-hexane. Yield: 45 mg (46%). FT-IR, nmax/cm 1: 30683035 (CH, aromatic), 2952-2888 (CH, aliphatic), 1650 (C5 5C, aromatic), 1506, 1440, 1342, 1268, 1186, 1124, 1089, 1015, 885, 738 cm 1. UV–vis (CHCl3) (1  10 5 M) lmax (nm) (log e/ dm3 mol 1 cm 1): 348 (4.99), 544 (4.33), 588 (4.18), 680 (3.99). MS (ESI) m/z: 2069.8 [M]+. Calcd. for C80H40N8S8F32ClFe: C 46.44; H 1.95; N 5.42; S 12.40. Found: C 46.32; H 2.06; N 5.54; S 12.27. 4.6. Bis(pyridine){octakis [2-fluoro-5(trifluoromethyl)benzylthio]porphyrazinato} iron(II) [FePz(py)2] (9) 8 (52 mg, 0.025 mmol) was dissolved in benzene (10 mL) and 0.1 mL of pyridine was added. The mixture was refluxed for 5 h under N2. After the solvent was removed under reduced pressure, the residue was dissolved in diethyl ether and added drop wise to DMF (10 mL). The precipitate formed was filtered and dried in vacuo. The pure porphyrazine was obtained by chromatography on silica gel using MeOH/CHCl3 (1:20) mixture as eluent. The product was soluble in CHCl3, CH2Cl2, THF, and acetone, but insoluble in n-hexane. Yield: 39 mg (72%). FT-IR, nmax/cm 1: 3065-3036 (CH, aromatic), 29752850 (CH, aliphatic), 1672 (C5 5C, aromatic), 1588, 1504, 1444, 1342, 1225, 1188, 1120, 1012, 880, 735 cm 1. UV–vis (CHCl3) (1  10 5 M) lmax (nm) (log e/dm3 mol 1 cm 1): 348 (4.97), 592 (4.67). 1H NMR (d, ppm): 7.72 (dd, 8H, Ar–H), 7.52 (dd, 8H, Ar–H), 7.30 (dd, 8H, Ar–H), 6.84 (m, py-Hc), 4.75 (m, py-Hb), 4.64 (s, 16H, S–CH2), 2.35 (m, py-Ha). 19 F NMR (d, ppm): 144.4 (o-fluoro), 63.46. MS (ESI) m/z: 2191.1 [M]+. Calcd. for C90H50N10S8F32Fe: C 49.32; H 2.30; N 6.39; S 11.70. Found: C 49.44; H 2.41; N 6.27; S 11.83. 4.7. m-Pyrazine{octakis [2-fluoro-5-(trifluoromethyl)benzylthio] porphyrazinato} iron(II) [FePz(pyz)]n (10) 8 (103 mg, 0.05 mmol) and pyrazine (374 mg, 5.0 mmol) were mixed and melted at 80 8C under N2 and the mixture was kept at

60 8C for 5 h. The excess pyrazine was sublimed under high vacuum for 8 h. Yield: 61 mg (58%). FT-IR, nmax/cm 1: 3072-3030 (CH, aromatic), 2975-2865 (CH, aliphatic), 1675 (C5 5C, aromatic), 1504, 1446, 1348, 1269, 1184, 1118, 1055, 889, 735 cm 1. UV–vis (CHCl3) (1  10 5 M) lmax (nm) (log e/dm3 mol 1 cm 1): 370 (4.85), 625 (4.64), 710 (4.18). 1H NMR (d, ppm): 7.70 (dd, 8H, Ar– H), 7.50 (dd, 8H, Ar–H), 7.33 (dd, 8H, Ar–H), 4.60 (s, 16H, S–CH2), 2.26 (s, 4H, pyz-H). 19F NMR (d, ppm): 144.6 (o-fluoro), 63.46. Calcd. for (C84H44N10S8F32Fe)n (2113.65)n: C 47.73; H 2.10; N 6.63; S 12.14. Found: C 47.85; H 2.22; N 6.50; S 12.02. Acknowledgements This work was supported by the Scientific Research Fund of Fatih University under the project number P50011204_B. Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.jfluchem.2013. 02.012. References [1] R. Bonnett, Chem. Soc. Rev. 24 (1995) 19–33. [2] I. Rosenthal, in: C.C. Leznoff, A.B.P. Lever (Eds.), Phthalocyanines: Properties and Applications, vol. 4, VCH, Weinheim, 1996, pp. 485–507. [3] G.E. Collins, N.R. Armstrong, J.W. Pankow, C. Oden, R. Brina, C. Arbour, J.P. Dodelet, J. Vac. Sci. Technol. A11 (1993) 1383–1391. [4] G.C. Bryant, M.J. Cook, T.G. Ryan, A.J. Thorne, J. Chem. Soc. Chem. Commun. (1995) 467–468. [5] C. Piechocki, J. Simon, A. Skoulios, D. Guillon, P. Weber, J. Am. Chem. Soc. 104 (1982) 5245–5247. [6] M.A. Diaz-Garcia, I. Ledoux, J.A. Duro, T. Torres, F. Agullo´-Lo´pez, J. Zyss, J. Phys. Chem. 98 (1994) 8761–8764. [7] H. Schultz, H. Lehmann, M. Rein, M. Hanack, in: J.W. Buchler (Ed.), Metal Complexes with Tetrapyrrole Ligands II, Structure and Bonding, vol. 74, SpringerVerlag, Berlin, 1990, pp. 41–146. [8] C. Feucht, T. Linssen, M. Hanack, Chem. Ber. 127 (1994) 113–117. [9] S.L. Michel, S. Baum, A.G.M. Barrett, B.M. Hoffman, in: K.D. Karlin (Ed.), Progress in Inorganic Chemistry, vol. 50, John Wiley & Sons, New York, 2001, pp. 473–590. [10] P.A. Stuzhin, C. Ercolani, in: K.M. Kadish, K.M. Smith, R. Guilard (Eds.), The Porphyrin Handbook, vol. 15, Academic Press, New York, 2003, pp. 263–365. [11] V.N. Kopranenkov, E.A. Lukyanets, Russ. Chem. Bull. 44 (1995) 2216–2232. [12] M.S. Rodriguez-Morgade, P.A. Stuzhin, J. Porphyrins Phthalocyanines 8 (2004) 1129–1165. [13] A.G. Montalban, S.M. Baum, A.G.M. Barrett, B.M. Hoffman, Dalton Trans. (2003) 2093–2102. [14] M.J. Fuchter, C. Zhong, H. Zong, B.M. Hoffman, A.G.M. Barrett, Aust. J. Chem. 61 (2008) 235–255. [15] B.E. Smart, J. Fluorine Chem. 109 (2001) 3–11. [16] C. Isanbor, D. O’Hagan, J. Fluorine Chem. 127 (2006) 303–319. [17] K.L. Kirk, J. Fluorine Chem. 127 (2006) 1013–1029. [18] E. Zenkevich, E. Sagun, V. Knyukshto, A. Shulga, A. Mironov, O. Efremova, R. Bonnett, S.P. Songca, M. Kassem, J. Photochem. Photobiol. B33 (1996) 171–180. [19] S.K. Pandey, A.L. Gryshuk, A. Graham, K. Ohkubo, S. Fukuzumi, M.P. Dobhal, G. Zheng, Z. Ou, R. Zhan, K.M. Kadish, A. Oseroff, S. Ramaprasad, R.K. Pandey, Tetrahedron 59 (2003) 10059–10073. [20] I. Kumadaki, A. Ando, M. Omote, J. Fluorine Chem. 109 (2001) 67–81. [21] T. Goslinski, J. Piskorz, J. Photochem. Photobiol. C: Photochem. Rev. 12 (2011) 304–321. [22] J. Piskorz, P. Skupin, S. Lijewski, M. Korpusinski, M. Sciepura, K. Konopka, S. Sobiak, T. Goslinski, J. Mielcarek, J. Fluorine Chem. 135 (2012) 265–271. [23] D. Koc¸ak, E. Gonca, J. Fluorine Chem. 131 (2010) 1322–1326. [24] M. Altunkaya, E. Gonca, Polyhedron 30 (2011) 1035–1039. [25] N. Ag˘gu¨n, E. Gonca, J. Fluorine Chem. 140 (2012) 54–58. [26] H. Kunt, E. Gonca, Polyhedron 38 (2012) 218–223. [27] S. Kayako¨y, E. Gonca, Inorg. Chem. Commun. 21 (2012) 28–31. [28] M. Selc¸ukog˘lu, E. Hamuryudan, Dyes Pigments 74 (2007) 17–20. [29] M. Selc¸ukog˘lu, E. Hamuryudan, Dyes Pigments 77 (2008) 457–461. ¨ zc¸es¸meci, E. Hamuryudan, Polyhedron 29 (2010) 2710–2715. [30] M. Selc¸ukog˘lu, I˙. O [31] C.J. Schramm, B.M. Hoffman, Inorg. Chem. 19 (1980) 383–385. [32] N.B. McKeown, Phthalocyanine Materials: Synthesis Structure and Function, Cambridge University Press, Cambridge, 1998, 193-211. [33] F.H. Moser, A.L. Thomas, The Phthalocyanines, vols. I–II, CRC Press, Boca Raton, FL, 1983. [34] C.C. Leznoff, A.B.P. Lever (Eds.), Phthalocyanines Properties and Applications, vols. I–IV, VCH, New York, 1989–1996.

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