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Manganese(II) complexes (DMSO){(DMSO)₂bis[5,7-di-tert-butyl-2-(2-hydroxyphenolato)-1,3-benzoxazol-4-ol]}manganese(II) (Ia) and (DMSO)₂{bis[5,7-di-tert-butyl-2-(2-hydroxyphenolato)-5-nitro-1,3-benzoxazol-4-ol]}manganese(II) (Ib) are synthesized from the tridentate sterically hindered Schiff bases: condensation products of 4,6-di-tert-butyl-2-aminophenol with salicylaldehyde derivatives N-(3,5-di-tert-butyl-2-oxyphenyl)salicylaldimine and N-(3,5-di-tert-butyl-2-oxyphenyl-5-nitro)salicylaldimine. The structures and compositions of the synthesized metal chelates are characterized by C, H, and N elemental analysis, IR spectroscopy, and magnetochemical measurement data. The EPR data in DMF and toluene are presented for complex Ia. The molecular structures of complexes Ia and Ib are proved by X-ray diffraction (XRD) results (CIF files CCDC nos. 2325776 (Ia) and 2325777 (Ib), respectively). In both complexes, the manganese ion exists in the octahedral {N2O4} ligand environment in which the coordination occurs due to two nitrogen atoms of the benzoxazole cycle and two oxygen atoms of the o-hydroxyphenol group and the apical positions are occupied by the oxygen atoms of two DMSO molecules.

Two approaches to the preparation of chromium complexes of condensed heterocyclic compounds bearing two nitrogen atoms are approved. The reactions of benzimidazole (L¹) and 2-methylbenzimidazole (L²) with triammine(tricarbonyl)chromium (I) give the corresponding pentacarbonylchromium derivatives [(η¹-C₇H₆N₂)]Cr(CO)₅ (II) and [2-Me-(η¹-C₇H₅N₂)]Cr(CO)₅ (III) characterized by the nitrogen–chromium σ-bond, and ammine(pentacarbonyl)chromium (Cr(NH₃)(CO)₅, IV) is formed as a by-product. Analogous reactions involving 1,2,3,4-tetrahydroquinoxaline (L³) and 3-phenyl-1,2-dihydroquinoxaline (L⁴) afford tricarbonylchromium π-complexes [(η⁶-C₆H₄)C₂H₆N₂)]Cr(CO)₃ (V) and [3-Ph-(η⁶-C₆H₄)C₂H₃N₂)]Cr(CO)₃ (VI), respectively. The condensations of (η⁶-ortho-phenylenediamine)tricarbonylchromium (VII) with benzaldehyde and of ortho- phenylenediamine with (η⁶-benzaldehyde)tricarbonylchromium (VIII) afford acyclic compounds (azomethines [PhCH=N(η⁶-C₆H₄)NH₂]Cr(CO)₃ (IX) and [(η⁶-Ph)CH=NC₆H₄NH₂]Cr(CO)₃ (X), respectively), whereas the reaction of acetaldehyde with complex VII gives a mixture of heterocyclic products: exo-[1,3-bis-(C₂H₄OEt)-2-Me-(η⁶-C₆H₄)CHN₂]Cr(CO)₃ (XI) and endo-[1,3-bis-(C₂H₄OEt)-2-Me-(η⁶-C₆H₄)CHN₂]Cr(CO)₃ (XII). The spectral characteristics of the synthesized compounds are studied, and their purity and individual character are proved. The molecular structures of complexes III and XI are determined by XRD (CIF files CCDC nos. 2245463 (III) and 2362231 (XI)).

Single crystals of the Mn(III) complexes with tetradentate (N₂O₂) Schiff bases (L) and dicyanometallates [Mn(L)M(CN)₂]_n, where L = Salpn^2– = N,N’-bis(salicylidene)-1,3-diaminopropane, M = M = Ag⁺ (I), Au⁺ (II) were obtained for the first time. The molecular structures of I and II were determined by X-ray diffraction (CCDC no. 2351118 (I), 2351119 (II)). It was found that the dicyanometallate anion [M(CN)₂]ˉ in the crystal structure of these compounds acts as a bridge binding the Mn(III) moieties with the Schiff base into 1D. Using quantum chemical calculations, the (3, –1) type critical points were found near the C‒H…Ag/Au contact; this attests to the existence of weak hydrogen bonds between these atoms.

It was found that monovalent thulium iodide TmI in the TmI_x mixture reacts with hydrogen at 200°C and atmospheric pressure, forming a hydrogenation product [TmI_xH], which is confirmed by the reaction with (C₆F₅)₃GeBr, leading to the formation of (C₆F₅)₃GeН. In the reaction with nitrogen at 450°C, a mixture is formed containing diiodide TmI₂ and a product of the composition [Tm₄IN], containing a Tm–N valence bond. TmI in the TmI_x mixture also reacts with phenol and phenylacetylene. In the first case, a difficult-to-separate mixture of iodide phenolates TmI_x(OPh)_y is formed. The reaction with PhC≡CH leads to the formation of styrene, diphenylbenzene and a mixture of triphenylbenzenes. In the reaction of TmI_x with СО₂, trivalent thulium iodioxalate (C₂O₄)TmI(DМЕ).was isolated with a high yield.