Vol 49, No 5 (2023)

The first salt of alkaline metal and L-tryptophane, K2(L-Trp)2(H2O) (I), is synthesized by the reaction of L-tryptophane (HTrp) with potassium hydroxide in an aqueous-alcohol solution. Compound I is characterized by IR and 1H NMR spectroscopy and X-ray diffraction (XRD) (CIF file CCDC no. 2184367). Compound I is found to have a layered structure due to the presence of the bridging water molecule and chelate-bridging anions. The quantum chemical calculations of the crystal structure (PBE, plane-wave basis set, 800 eV) is used to evaluate the strength of interactions of the potassium ion with the L-tryptophanate anion (depending on the coordination type) and the influence of the anion conformation on the strength of coordination, hydrophobic, and hydrophilic interactions.

The ionic compound [Co(OC5H2N(NO2)2)4]((C2H5)3NH)2 (I) was synthesized by the reaction of CoCl2·6H2O with 2-hydroxy-3,5-dinitropyridine in acetonitrile in the presence of triethylamine as a deprotonating agent. The structure of compound I was studied by X-ray diffraction (CCDC no. 2196071) and thermodynamic characteristics of I were determined.

The reaction of thulium shavings with iodine at 680°C gave a poorly separable product mixture A, consisting of thulium metal (65%), TmI2 (14%), and TmI (21%). Monovalent thulium iodide could not be isolated in a pure state, but its presence among the products was confirmed, apart from magnetic measurements, by reactions with naphthalene and perylene, which proceed under mild conditions. The reaction of TmI with naphthalene, which takes place at –40°C, affords the trivalent thulium complex with naphthalene dianion, [TmI(C10H8)(DME)3]. The multistep reaction with perylene starts with the formation of the divalent thulium radical anion complex, [(TmI)+(C20H12)–•(DME)3], and ends in the formation of trivalent thulium complex, [(TmI)2+(C20H12)2–(DME)3]. The presence of a radical anion intermediate in the reaction mixture in an early stage was confirmed by ESR spectroscopy.

The reaction of equimolar amounts of pentaphenylantimony with camphor-10-sulfonic, 2,4-dinitro-1-naphthol-7-sulfonic (flavianic), 1-naphthalenesulfonic, and 2-sulfobenzoic acids in benzene resulted in the synthesis of tetraphenylstibonium organosulfonates Ph4SbOSO2C10H15O∙H2O (I), Ph4SbOSO2C10H4(OH-1)(NO2)2-2,4∙PhH (II), Ph4SbOSO2(C10H7-1)∙H2O (III), and Ph4SbOSO2C6H4(COOH-2) (IV). According to X-ray diffraction data (CCDC no. 2119791 (I), 2121381 (II), 2116582 (III), and 2123516 (IV), the crystal of I contains trigonal-bipyramidal sulfonate molecules (the axial Sb−C and Sb−O bond lengths are 2.130(3) and 2.565(2) Å, respectively) and hydration water molecules, which form a centrosymmetric eight-membered ring (the S=O∙∙∙H−O−H∙∙∙O=S distances are 2.06 and 2.21 Å). In the molecules of II, the metal atom geometry is a distorted trigonal bipyramid (the axial Sb−C and Sb−O bonds are 2.133(2) and 2.643(3) Å, respectively). The Sb−O distance (2.842(3) Å) is longer in III than in I or II; the hydration water molecules form centrosymmetric twelve-membered rings with the anions (the S=O∙∙∙H−O−H∙∙∙O=S distances are 2.02 and 2.05 Å). Meanwhile, the crystal of compound IV consists of tetrahedral tetraphenylstibonium cations and (2-carboxy)benzenesulfonate anions with the intramolecular O−H∙∙∙O=S hydrogen bond (1.75 Å).