Vol 49, No 12 (2023)

Under the conditions of solvothermal synthesis, a new metal-organic coordination polymer of the composition Cd[H2L] (I, H4L = 4,4'-([2,2'-bipyridine]-6,6'-diylbis(oxy))diphthalic acid). According to X-ray diffraction analysis, each Cd(II) cation binds four organic ligands: one via the coordination of the chelate bipyridyl fragment, two via the bidentate coordination of deprotonated COO groups, and one more via the monodentate coordination of the protonated carboxylate group. The obtained three-dimensional metal-organic framework does not contain free space capable of including guest molecules. Compound I was characterized by powder X-ray diffraction, IR spectroscopy, elemental (C, H, N) and thermogravimetric analyses, and luminescence spectra were recorded for it.

It has been shown that boiling aqueous europium(III) acetate with trifluoroacetic acid in a dioxane-acetonitrile mixture leads to the formation of a polymer {[Eu(μ-OOCCF3)3(OH2)2]}n (I) containing solvate dioxane molecules. The interaction of I in CH2Cl2 with [Phen2Zn2(µ-OOCBut)2(OOCBut)2] (II) at room temperature forms a precipitate, recrystallization of which from acetonitrile gives an unusual trinuclear heterometallic heteroanionic complex Phen2Zn2Eu(µ3-OH)(OOCBut)4(OOCCF3 )2 (III). The structure of the obtained compounds was established according to X-ray diffraction data (CCDC No. 2235937-2235939). The optical properties of complex III were studied.

When PdCl2 reacts with [2,6-diisopropylphenyl]iminoacenaphthenone (dpp-mian) in dichloromethane, the compound 2[Pd(dpp-mian)Cl2]*[Pd(dpp-mian)2Cl2] (1) is formed. It contains two structural units: [Pd(dpp-mian)Cl2], in which dpp-mian is coordinated to Pd(II) in a bidentate-chelate manner by nitrogen and oxygen atoms, and [Pd(dpp-mian)2Cl2], in which two dpp-mian molecules are bonded to palladium only through a nitrogen atom. On the other hand, when PdCl2 interacts with [4-methoxyphenyl]iminoacenaphthenone (4-MeOPh-mian) in dichloromethane, a rearrangement of the ligand structure occurs, followed by the formation of the previously described in the literature complex of Pd(II) with 1,2-bis-[4-methoxyphenyl ]iminoacenaphthene (4-MeOPh-bian) of the composition [Pd(4-MeOPh-bian)Cl2] (2). Compound 1 was obtained for the first time and characterized by X-ray diffraction, as well as by X-ray diffraction, elemental analysis, IR spectroscopy and cyclic voltammetry.

A number of new bimetallic acetate and pivalate complexes of the Pd–Mn system have been synthesized and structurally characterized. The starting complex [Pd(OOCMe)4Mn] reacts with N donor ligands such as 1,10-phenanthroline to form [Pd(OOCMe)4Mn(phen)]·MeCN (I) (CIF file CCDC no. 2217716). The reactions of substitution of acetate bridges for pivalate bridges in heterometallic carboxylate Pd–Mn complexes have been studied; It has been shown that complete replacement of all acetate bridges with pivalate bridges is possible both in the heterometallic complex (I), in which there is a ligand coordinated to an additional metal atom, with the formation of the compound [Pd(Piv)4Mn(phen)]·C6H6, (II) ( CIF file CCDC No. 2217717), structurally close to the original acetate complex, and in the acetate complex [Pd(OOCMe)4Mn]. The heterometallic pivalate cocrystallizate [Pd(Piv)4Mn 2HPiv] (III) obtained in the latter case (CIF file CCDC No. 2217718) is capable of reacting with 5-nitro-1,10-phenanthroline to form the complex [Pd(Piv)4Mn( nphen)] (IV) (CIF file CCDC No. 2217719).

When preparing the ruthenium dimer [Ru(CO)2Cp]2 in the thermal reaction of cyclopentadiene with Ru3(CO)12, the tetranuclear cluster [Ru(μ3-CO)Cp]4 (I) was obtained as a minor product. Spectral (13C and 1H NMR, IR) and structural studies were carried out for cluster I. By crystallization under different conditions, two types of dark cherry crystals were obtained, cluster I itself (crystal 1) and its tetrahydrate (crystal 2), the structure of which was determined by X-ray diffraction. Structural data for 1 and 2 have been deposited in the Cambridge Structural Data Center (CCDC nos. 2241197 and 2241199, respectively; deposit@ccdc.cam.ac.uk; http://www.ccdc.cam.ac.uk). Based on a comparative analysis of cluster geometry, it is shown that the distortion of the Ru4(CO)4 framework in I from ideal Td symmetry in the structure of a pure compound is determined by the anisotropy of intermolecular contacts in the crystal. Features of chemical bonding in the [Ru(μ3-CO)Cp]4 cluster and its iron-containing analogue were studied using DFT calculations using topological analysis of electron density to compare energy characteristics and effective force constant bonding interactions. The necessity of using criteria for elastic deformations of interatomic interactions (force constants) for the correct description of structural and chemical phenomena, for example, such as the structural non-rigidity of the framework of transition metal clusters, has been demonstrated.