Tetratiya-makrohalkaları içeren yeni tip ftalosiyaninler /
Yazar: AYŞE GÜL GÜREK
Danışman: PROF.DR. BEKAROĞLU ÖZER
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü
Derece: Doktora, 1996
Konu: Kimya = Chemistry
Dizin: Ftalosiyaninler = Phthalocyanines

Özet:
ÖZET Ftalosiyaninler genellikle ftalonitril, ftalikanhidrit, ftalimid veya bunların substitüsyon ürünleri ile metal tuzlan arasındaki reaksiyonlardan elde edilebilirler. Ftalosiyaninler genellikle güç çözünen bileşiklerdir. Ftalosiyanin kimyasındaki önemli bir hedef de çözünür ürünler elde etmektir. Bu bileşiklerin çözünürlükleri, periferal olarak hacimli substitüentler (örneğin; -t- Bu, -C^H^, -OCj^H^), polar gruplar (örneğin; -S03Na, -NRj"1") veya makro halkalar ilavesiyle artınlabilmektedir. Makrohalkalar da ftalosiyaninlerin çözünürlüğünü arttırmaktadır. Taç eter, monoaza ve tetraaza makrohalkalan içeren ftalosiyaninlerin sentezi ve incelenmesi grubumuz tarafından yapılan çalışmaların büyük bir bölümünü oluşturmaktadır. Bu çalışmada, 2,2'-[(propan-l,3-diyil) bis(tiyo)] bis(etantiyol) ve 4,5- diklorobenzen-l,2-dikarbonitrilden yola çıkılarak 2,3,6, 7,9, 10-heksahidro-5H- {1,4,8,11] benzotetratiyasiklotridesin-13,14-dikarbonitril elde edilmiştir. Bu nitril türevinden periferal pozisyonlarda dört tane 13-üyeli tetratiyamakro halkalan içeren metalsiz ve metalo (M= Ni,Co,Zn) ftalosiyaninler sentezlenmiştir. Aza ve oksa-makrohalkalan içeren ftalosiyanin türevlerine karşılık bu ftalosiyaninlerin çözünürlükleri oldukça azdır. Ni(II), Zn(II) ftalosiyaninlerin etanoldeki süspansiyonlarından Pd(II) ve Ag(I) tuzlanyla penta nükleer kompleksleri elde edilmiştir. Elde edilen yeni maddelerin yapılan; Elementel analiz, DR, UV-VIS, NMR, MS spektrumları ve atomik absorpsiyon ölçümleri ile aydınlatılmıştır. -vu-

Abstract:
SUMMARY NEW PHTHALOCYANINES SUBSTITUTED WITH TETRATHIA MACROCYCLES One of the major areas of interest is coordination chemistry, in which the interaction of a central atom with surrounding atoms, ions or molecules is studied. Coordination compounds containing macrocyclic ligands have been known and studied since the beginning of this century; however until quite recently, the number and variety of these compounds was limited. In 1967 a new series of macrocyclic compounds which have the ability to function as complexing agents was reported by Pedersen. He prepared more than 60 compounds with a variety of ring size, a number of oxygens and substituent groups. He also discovered that these compounds formed complexes with many cations (mostly group I and II). Because of these unusual coplexation properties, many alkali salts can be dissolved in organic solvents by forming complexes with these macrocyclic polyethers. Due to the appearance of its molecular model and its ability to crown the cations, these cyclic polyethers were named "crown compounds". Generally, the alkali metal ions are regarded as poor complexing of alkali cations by neutral molecules is an uncommon phenomenon. After this discovery, crown compounds and their complexes have been extensively investigated. At the same time "hetero-crown compounds" such as cyclic polyamines and their complexes have also been prepared and studied. Crown componds have been studied as model systems in cation transport through cellular membranes. They have found use in organic chemistry to study certain chemical reactions including the catalsis of ionic organic reactions by solvolyzing catiönic species. -VU1-Few thermodynamic or chemical reaction studies have been carried out on macrocyclic ether sulfide compounds. Lehn and co-workers have also studied the physical properties of macro heterobicyclic diamines containing oxygen and sulfur atoms. Other workers have studied metal complexation of certain macrocyclic thioethers and macrocyclic thioether amines. The development of syntheses for new macrocyclic systems of potential interest for discrimination studies has been a major thrust of the program of research. In particular, emphasis has been given to the prepation of new oxygen- nitrogen donor macrocycles. These ligands, which incorporate various combinations and number of donor atoms, are intermediate in structure between the crown polyethers and the category of macrocycles which incorporate mainly nitrogen donors. The aim of this study is to synthesized a new macrocyclic compound containing S donor atoms which will be suitable to use as starting material for phthalocyanines and their complexes. The special nature of the macrocycle named "phthalocyanine" and its metal complexes have been known for about 60 years. Since then the unique physical and chemical properties of this class of coordination compounds have been exploited from both the practical as well as the theoretical point of view. Thus, metallophthalocyanines have important uses as commercial dyes, optical and electrical materials, and catalysts. In recent times compelling reason to study the detailed coordination chemistry of metallophthalocyanines has arisen. The great activity in bioinorganic chemistry has led to veritable avalanche of work on metalloporphyrins and other naturally occurring macrocylic coordination compounds. Thus the metallophthalocyanines are being examined in earnest and their properties compared to those of the porphyrin complexes in hopes of arriving at an understanding of how the naturally occurring macrocyclic porphyrin ligand affects the properties of the metal. -IX-Unsubstituted and substituted phthalocyanines are widely used as pigment and dyes. Various other properties for new applications were investigated more recently: photosentization in solution, photodynamic activity in the photodynamic cancer therapy, electrocatalysts for the dioxygen reduction in fuel cell reactions, photoreductions or photooxidations in photoelectrochemical cells, electrochromic processes as thin films, materials for electrophotography, charge seperation in photovoltaic cells, optical information storage systems, catalysts for mercaptan oxidations and use as sensors. For most of these applications, phthalocyanines bearing substituents had to be prepared in order to improve the above mentioned properties and to enhance the solubility or to perform coupling to other reagents like polymers. The rich coordination chemistry of phthalocyanine complexes has promoted the researches to "tailor" specific products with certain properties which are required by high technology applications. The two variables are the central metal ion and the peripheral substituents: when the possibility of inserting great number of different metal ions into phthalocyanine core is combined with the oppurtunity of unlimited number type of substituents, the possibility of obtaining novel products is infinite. In the last decade the synthesis and study of new phthalocyanines with functional substituents has grown impressively, particularly in the light of the possibility of achieving wide application of these colored compounds in non- traditional fields of technology which include fuel cells, chemical sensors, solar cells,electrophotography and the photodynamic therapy of cancer. A common prerequisite for the materials for each field is solubility in practical solvents. Additional factors such as wavelength of the Q band absorption, thermal stability, electrical conductivity and redox potentials are accomplished by purpose-designed substitution patterns. We have described for the first time the synthesis of novel soluble phthalocyanines where crown ether moieties are integral parts on the periphery. They have been shown to be capable of binding alkali metal cations. Another success of this approach has been demonstrated by the fact that these molecules lead to ion channels for alkali ions in the condensed phase and form discotic mesophases. Additionally, its bis(phthalocyaninato)lutetium derivative has been a starting point for a completely new field of iono-electronics. -x-The second important step in combining macro-heterocycles with phthalocyanines has been the synthesis of phthalocyanines with four 14- or 15- membered tetraazamacrocycles which give the opportunity to prepare pentanuclear complexes with transition metal ions. Monoazatetraoxa-,diazatrioxa and diazadioxa- macrocycles have been also substituted on the phthalocyanine nucleous, but their interactions with alkali and transition metal ions have been negligible. Even a two-fold-macrocycle substitution on the phthalocyanine core has been accomplished by starting with a dicyano-compound carrying a 15- crown-5 moiety together with a 14-membered tetraaza-macrocycle. As donors, thioethers can be placed between oxa- and aza-groups for their tendency to complex with alkali and transition metal ions. Thioether groups on the benzene rings of phthalocyanine were also proven to be effective, as shown by relatively few communications reporting alkylthio-substituted derivatives to shift the Q-band absorption of the phthalocyanine to lower energy region. We report now a new group of phthalocyanines fused to four 13-membered tetrathia-macrocycles on the periphery as a further step of the series on macrocycle-fused phthalocyanines. As in the case of all other substituted phthalocyanines, a new derivative with tetrathia-macrocyclic substituents requires a phthalic acid derivative carrying this group at the beginning. Our first aim was to prepare a 15-membered tetrathia macrocycle with o-dibromo functions on the benzene groups similar to those reported earlier in the literature by condensing l,2-bis(bromomethyl)-4,5- dibromo benzene with 2,2'-[propane-l,3-diyl) bis(thio)]bis (etanethiol). The dibromo derivative would then be converted into a carbonitrile by a Rosenmund von Braun reaction. However, all efforts to accomplish these reactions failed in the second step, no carbonitriles could be observed (Scheme 1). HS HS c X = Br // > phthalocyanine X = CN Scheme 1. Synthesis of 15-membered tetrathia-macrocycles substituted compounds -XI-Similarly, no phthalocyaninatocopper was detected in number of trials to convert the dibromo compound directly in high boiling solvents such as quinoline, DMF at reflux temperature or in pyridine in a sealed tube. To over come these difficulties a new macrocycle was designed which would carry phthalonitrile unit from the beginning. Here we used the nucleophilic displacement reaction of 4,5-dichlorophthalonitrile with the dithiol compound in the presence of excess sodium carbonate as reported recently to prepare some bis(alkylthia)- or bis(alkoxy)-phthalonitrile derivatives recently (Scheme 2). Of course, it was necessary to use equivalent amounts of the two reagents to force a 1:1 condensation, but some 2:2 condensation products and others were unavoidable, so the yield of the desired compound was only 21 % after chromatographic isolation. Iminoisoindoline derivative 4 was obtained by bubling ammonia through a solution of 3 in methanol-butanol mixture in the presence of sodium methylate. NC. ^^ a NC, " XX - XC D NC - CI NC 2 ?a "> Scheme 2. Synthesis of new phthalocyanines peripherally fused to four 13- membered tetrathiamacrocycles -xn-The usual synthetic routes were applied to obtain the metal-free and the phthalocyaninatometals. Thus, either 4 was heated to its melting point and kept at this temperature for about 0.5 h or, more precisely, 3 was cyclotetramerized to 5 in pentanol at reflux^temperature in the presence of a strong organic base such as 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU). As a high boiling aprotic solvent, quinoline was the solvent of choice for the preparation of phthalocyaninatonickel (II) 7, -zinc(II) 8, whereas cyclotetramerization of 3 to the Co derivative 6 was carried out in ethyleneglycol with better yields. Many attempts to obtain phthalocyaninatocopper(II), including the reaction of acetylacetonatocopper(H) and 4 in 2-(dimethylamino)ethanol, led to intensly coloured products. But the latter did not give satisfactory elemental analysis probably due to metalic contamination on tetrathiamacrocycles which could not be eliminated. A common feature of the phthalocyanines 5-8 in contrast to the tetraaza- macrocycle- or crown ether-substituted analogues, is their insolubility in the usual solvents. Only 6 and 8 are soluble in donor solvent such as pyridine to a certain extend. Since phthalocyanines with bulky peripheral substituents (e.g. long alkyl- or alkoxy-chains, t-butyl or neopentoxy groups, crown ethers, etc.) are known to be soluble in common organic solvents, these findings bring a contradiction to the well accepted rule. However, our previous experience with a vic-dioxime ligand carrying a similar 13-membered tetrathia macrocycle has shown that the complexes are insoluble in common solvents in contrast to the well soluble crown ether or aza-ether analogs. Therefore, the insolubility of the new phthalocyanines 5-8 is a consequence of the tetrathia macrocycle which does not lie on the plane of the phthalocyanine cores as observed from the model systems. The solubility of 6 and 8 in pyridine is a consequence of binding of the solvent molecules as axial ligands in Co(II) and Zn(II) complexes. Although low solubility of the new phthalocyanines is an obstacle to investigate the interaction of the thia donor groups with metal ions in similar conditions as in the case of crown ether or tetraaza-macrocycle-substituted ones, it is also possible to carry out this complexation as suspension. In this context we could isolate Pd(II) complexes of phthalocyanines 7 and 8 and Ag(I) complex of 8 with one metal ion for each tetrathia macrocycle. The solubility of these pentanuclear products are even lower than the parent phthalocyanines and their complexes through thia-groups decompose when treated with solvents of high donor capacity such as pyridine. -xni-ER spectrum of 3 clearly indicates the presence of alkyl and cyano groups by the intense characteristic stretching bands of C-H around 2960-2920 cm and C=N at 2220 cm"1. The latter has been disappared after conversion of 3 to iminoisoindoline compound 4 which shows absorption at 3405 and 3220 cm for the NH groups. After the cyclotetramerization reaction, the ER spectra of the phthalocyanines 5-8 are very similar with the exception of N-H stretching frequency of inner core at 3270 cm" in metal-free derivative 5. In the H-NMR spectrum (Dg)DMSO of 3, aromatic protons appear as a singlet at 8.14 ppm and the aliphatic protons as three triplets and a pentate at 3.44 - 1.56 ppm as expected. C-NMR spectrum of 3 shows 4 different signals for the unsaturated C-atoms, one arising from ON(115.46 ppm). As a consequence of the symmetric structure, the aliphatic C-atoms also give 4 different signals between 32.21-28.76 ppm. The only soluble phthalocyanine 8, shows signals for 4 aromatic and 3 aliphatic C-atoms, the aliphatic atoms C(3) and C(5) with relatively similar chemical environment having the same chemical shift. The VIS spectra of the phthalocyanines 6 and 8 in pyridine show the intense Q band absorptions at 680 and 714 nm. There is also a shoulder at slightly higher energy side for both products. The longer wavelength encountered for Zn(II) phthalocyanine 8 is especially noteworthy to denote the shift of this intense band to near IR region as a result of S-substitution with respect to the unsubstituted or N- or O-substituted phthalocyanines. A close investigation of the mass spectra of the phthalonitrile derivative 3 and Zn(II) phthalocyanine 8 has confirmed the proposed structures. In the case of 3, in addition to the M+ peak at 352, fragment ions corresponding to the loss of CH2CH2 ([M-28]+), CH2CH2SCH0CH2CH2SCH2 ([M-149]+) and CH2CH2SCH2CH2CH2SCH2CH2 ([M-162]^) have been easily identified. The spectrum of 8 was obtained by FAB technique using a HCOOH and glycerine matrix; the region of the molecular ion (ra/z 1476) and the other bigger fragment ions are occured together with the corresponding leaving groups. The fragmentation pattern closely follow that of 3 indicating the high stability of the phthalocyanine core. -xiv-