*Article* **Sulfanyl Porphyrazines with Morpholinylethyl Periphery—Synthesis, Electrochemistry, and Photocatalytic Studies after Deposition on Titanium(IV) Oxide P25 Nanoparticles**

#### **Tomasz Koczorowski 1,\* , Wojciech Szczolko <sup>1</sup> , Anna Teubert <sup>2</sup> and Tomasz Goslinski <sup>1</sup>**



**Citation:** Koczorowski, T.; Szczolko, W.; Teubert, A.; Goslinski, T. Sulfanyl Porphyrazines with Morpholinylethyl Periphery—Synthesis, Electrochemistry, and Photocatalytic Studies after Deposition on Titanium(IV) Oxide P25 Nanoparticles. *Molecules* **2021**, *26*, 2280. https://doi.org/10.3390/ molecules26082280

Academic Editor: Ana Margarida Gomes da Silva

Received: 29 March 2021 Accepted: 13 April 2021 Published: 15 April 2021

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**Abstract:** The syntheses, spectral UV–Vis, NMR, and electrochemical as well as photocatalytic properties of novel magnesium(II) and zinc(II) symmetrical sulfanyl porphyrazines with 2-(morpholin-4 yl)ethylsulfanyl peripheral substituents are presented. Both porphyrazine derivatives were synthesized in cyclotetramerization reactions and subsequently embedded on the surface of commercially available P25 titanium(IV) oxide nanoparticles. The obtained macrocyclic compounds were broadly characterized by ESI MS spectrometry, 1D and 2D NMR techniques, UV–Vis spectroscopy, and subjected to electrochemical studies. Both hybrid materials, consisting of porphyrazine derivatives embedded on the titanium(IV) oxide nanoparticles' surface, were characterized in terms of particle size and distribution. Next, they were subjected to photocatalytic studies with 1,3-diphenylisobenzofuran, a known singlet oxygen quencher. The applicability of the obtained hybrid material consisting of titanium(IV) oxide P25 nanoparticles and magnesium(II) porphyrazine derivative was assessed in photocatalytic studies with selected active pharmaceutical ingredients, such as diclofenac sodium salt and ibuprofen.

**Keywords:** catalysis; electrochemistry; morpholine; porphyrazine; titanium(IV) oxide
