The reaction of methyl anthranilate with 2-methylphenyl- iso -selenocyanate in boiling absolute ethanol affords a new compound: 3-(2-methylphenyl)-2-selenoxo-2,3-dihydroquinazolin-4(1 Н )-one (HL). Free ligand HL, which is selone, is preliminarily transformed into the corresponding sodium selenolate [C 15 H 11 N 2 OSeNa] ( I) , which is then used without isolation in the reaction with cadmium chloride. This reaction leads to the formation of complex [Cd 2 (μ-L) 2 (L) 2 (C 2 H 5 OH) 2 ] ( II ). The structures of the compounds are determined by X-ray diffraction (XRD) (CIF files CCDC nos. 2142342 (НL) and 2246014 ( II )) and NMR spectroscopy ( 1 Н, 13 С, 15 N, and 77 Se). In the crystal, the molecules of HL form one-dimensional chains due to H…O and H…Se contacts and alternate in the syndiotactic order. Compound II is the centrosymmetric binuclear complex [C 64 H 56 Cd 2 N 8 O 6 Se 4 ]. The cadmium atoms in complex II are hexacoordinated by two chelate anionic ligands L – . According to the NMR data, in a DMSO-d 6 solution free ligand HL has the selone structure, whereas in cadmium complex II this ligand exists in the selenolate form, which is consistent with the XRD data on the crystal structures of the compounds.

Three new organoselenium compounds are synthesized: N-phenyl-2-(2-thienylacetyl)hydrazinecarboselenoamide (I), 4-phenyl-5-(2-thienylmethyl)-2,4-dihydro-3H-1,2,4-triazole-3-selone (II), and 3,3'-di[4-phenyl-5-(2-thienylmethyl)-4H-1,2,4-triazolyl] diselenide (III). Two of them (compounds II and III) are characterized by X-ray diffraction analysis (CIF files CCDC nos. 1956602 (II) and 1956603 (III)). Compound II crystallizes in the monoclinic crystal system (space group P21/n) with two crystallographically independent molecules A and B being different conformers relative to rotation about the NTrz–CTrz–C(H2)–CTph bond, where Trz is triazole and Tph is thiophene (gauche-A (51.4(3)°) and cis-B (4.2(4)°)). In the crystal of compound II, molecules A and B form chains along the crystallographic axis a due to strong hydrogen bonds N–H···Se. Then the chains are bound into a three-dimensional framework via intermolecular nonvalent interactions Se···S (3.3857(11) Å). Owing to the anomeric effect, diselenide III is characterized by the typical gauche conformation of the substituents at the Se–Se bond (torsion angle СSeSeС 83.5(4)°) stabilized by a weak intramolecular hydrogen bond С–H···π. In the crystal of compound III, the molecules form chains along the crystallographic acid b due to intermolecular noncovalent interactions Se···π(C–C) (3.404(6) and 3.458(12) Å), Se···Se (3.8975(11) Å), and S···N (3.250(5) Å). Bactericidal and fungicidal activity of the synthesized compounds is studied.