0022-4766/18/5903-0571 © 2018 by Pleiades Publishing, Ltd. 571 Journal of Structural Chemistry. Vol. 59, No. 3, pp. 571-583, 2018. Original Russian Text © 2018 G. K. Kantar, M. Kaya, O. Şahin, S. Şaşmaz. GUAIACOL SUBSTITUTED AzaPCs: A NOVEL SYNTHESIS METHOD AND INVESTIGATION OF PHOTOPHYSICAL PROPERTIES G. K. Kantar 1 , M. Kaya 1 , O. Şahin 2 , and S. Şaşmaz 1 AzaPCs containing tetra- and octaguaiacol moieties have not been investigated up to now. In this study, an unusual method is used for the synthesis of metalloAzaPCs (M: Zn, Co, Cu) containing guaiacol moieties. All compounds are characterized by a combination of FT-IR, 1 H NMR, 13 C NMR, mass and UV/vis spectroscopy techniques. The molecular structure of starting pyrazine compounds 1 and 2 is also determined by the single crystal X-ray diffraction technique. The aggregation behavior of new Zn(II) AzaPCs is investigated in DMSO at different concentrations. The fluorescence properties of Zn(II) AzaPCs are investigated in different solvents. The fluorescence quantum yields of Zn(II) AzaPCs are calculated in DMSO. DOI: 10.1134/S0022476618030101 Keywords: AzaPC, guaiacol, fluorescence. INTRODUCTION Azaphtalocyanines (AzaPCs) are aza-analogues of phthalocyanines (PCs) in which some carbon atoms are replaced by nitrogen atoms in the Pc macrocycle [1]. These macrocyles have attracted the attention of researchers owing to their promising photosensitive [2-4], fluorescent [5-8], non-linear optical [9], and oxidative properties [10]. Eight additional nitrogen atoms on the periphery of AzaPc increase the polarity of these macrocycles, and substituents may be used for tuning the solubility, UV-vis absorptions, i.e. shifts of Q-bands, and acid-base properties [11]. Substituted AzaPCs are generally more soluble than the corresponding PCs, therefore they are more applicable in various technological areas [12]. Guaiacol (2-methoxy phenol) is a phenolic compound widely distributed in various plants and it can also be found in common foods and plant origins [13].The guaiacol derivatives have definitely a positive effect on human health due to their anti-allergenic, anti-artherogenic, anti-inflammatory, antioxidant, antimutagenic, and antimicrobial activity [14-16]. The literature survey shows that guaiacol substituted PCs were synthesized and some properties were investigated [17]. In addition, single crystals of guaiacol substituted phtalonitrile compounds were reported previously [18]. However, the synthesis and characterization of tetra- and octaguaiacol substituted metalloAzaPCs have not been investigated until now. Phenoxy group substituted AzaPCs are of potential interest for a variety of applications, particularly fluorophores, since their 1 Recep Tayyip Erdogan University, Science and Art Faculty, Department of Chemistry, Rize, Turkey; gunay.kaya@erdogan.eru.tr. 2 Sinop University, Scientific and Technological Research Application and Research Center, Sinop, Turkey; onurs@omu.eru.tr. The text was submitted by the authors in English. Zhurnal Strukturnoi Khimii, Vol. 59, No. 3, pp. 594-606, March-April, 2018. Original article submitted October 19, 2016; revised January 1, 2017.