S. G. Sakharov

Crown-substituted Sc(III) phthalocyaninates: Synthesis and spectral properties

The scandium(III) complexes with tetra(15-crown-5)phthalocyanine [Sc(R4Pc)2]·0 (I) and Sc(R4Pc) · OAc (II) have been synthesized by condensation of Sc3+ with phthalocyanine H2R4Pc (4,5,4′,5′,4″,5″,4‴,5‴-tetrakis(1,4,7,10,13-pentaoxatridecamethylene)phthalocyanine). Compounds I and II have been characterized by spectral methods: electronic absorption spectroscopy, MALDI-TOF MS, IR spectroscopy, and 1H NMR. The redox properties of I and the photoluminescent properties of II have been studied.

Molybdenum(VI) complexes with N-substituted hydroxylamines

New molybdenum(VI) complexes with N-monoalkylsubstituted hydroxylamines have been synthesized and studied. The structure of [MoO2(C2H5NHO)2] and [MoO2(i-C3H7NHO)2], whose distinguishing feature is the bidentate chelate coordination of the ligand to molybdenum with the formation of the three-membered NMoO chelate ring, has been determined by X-ray diffraction.

Cation-induced aggregation of sandwich lutetium(III) and Yb(III) complexes with tetra(15-crown-5)-substituted phthalocyanine as probed by 1H NMR

The cation-induced aggregation of sandwich crown-substituted complexes [Ln(R4Pc)2] (Ln = Lu (I) and Yb (II), R4Pc2− is the 4,5,4′,5′,4″,5″,4‴,5‴-tetrakis(1,4,7,10,13-pentaoxatridecamethylene)phthalocyaninate ion) and Ln2(R4Pc)3(Ln = Lu (III) and Yb (IV) in a CDCl3-DMSO-d6 solution has been studied by 1H NMR. The data obtained are consistent with the conclusions concerning the composition of supramolecular aggregates drawn from spectrophotometric titration data. The molecules of double-decker complexes I and II form supramolecular oligomers, whereas triple-decker complexes III and IV form supramolecular dimers, which is presumably due to the stronger distortion of the planes of the outer decks of the triple-decker complexes as compared to their double-decker analogues.

Iron cyclopentadienyl(triphenylphosphine)carbonylphenyl telluride adducts with manganese, tungsten, and rhodium complexes

The reactions of CpFe(CO)(PPh3)TePh (I) with CpMn(CO)2(THF), W(CO)5(THF), and [Cp*RhCl2]2 gave heterometallic adducts CpFe(CO)(PPh3)(µ-TePh)CpMn(CO)2 (II), CpFe(CO)(PPh3)(µ-TePh)W(CO)5 (III), and CpFe(CO)(PPh3)(µ-TePh)RhCl2Cp* (IV). The structures of II, III, and IV · 3CDCl3 (CIF files CCDC nos. 063654, 1063655, 1038123) were studied by X-ray diffraction. In all complexes, metal atoms are connected by only one tellurophenyl bridge. All M → Te bonds are substantially shortened with respect to the sum of the covalent radii owing to the additional M → Te dative interactions.

Structures of the silver complexes with lutidines according to the NMR data. Crystal structure of [AgNO3(3,5-Lut)2]

The silver(I) nitrate complexes with 2,3-, 2,4-, 2,6-, and 3,5-lutidine (Lut, dimethylpyridine C7H9N), [AgNO3(Lut)2], are synthesized and studied by multinuclear NMR (1H, 13C, and 15N) in various solvents (chloroform, dimethyl sulfoxide, and acetonitrile). The influence of steric and electronic factors of the organic ligand on the parameters of the NMR spectra is revealed. It is shown that the 15N NMR spectra are the most informative. The structure of complex [AgNO3(3,5-Lut)2] is determined. The crystals are monoclinic, space group C2/c, a = 14.599(1) Å, b = 8.422(1) Å, c = 12.954(1) Å, β = 99.60(1)°, V = 1570(2) Å3, ρcalcd = 1.625 g/cm3, Z = 4. The structure is built of discrete neutral complexes [AgNO3(3,5-Lut)2]. The coordination mode of the Ag+ ion includes two nitrogen atoms of two crystallographically equivalent lutidine ligands (Ag-N 2.194(5) Å, angle NAgN 147.6(3)°). The nitrate ion behaves as a weak chelating ligand with respect to the Ag+ ion (Ag…O 2.674(6) Å).

“Forced” coordination modes of 1,2-cyclohexanedione dioxime in uranyl complexes

Unusual coordination modes of 1,2-cyclohexane dionedioxime in uranyl complexes, i.e., tridentate chelating/bridging and (E, Z)-pentadentate chelating/bridging ones, were established by X-ray crystallography of single crystals of (CN3H6)3[(UO2)2(C6H9N2O2)(C6H8N2O2)(C2O4)2] · 2H2O and [(UO2)2(C6H8N2O2)2(H2O)3] · 2H2O. The conditions of the emergence of such coordination modes were determined. The possibility of (E/Z) izomerization of α-dioximes in reactions of uranyl complexes.

Cadmium(II) iodide molecular coordination compounds with 4-methylpyridine and 4-methylquinoline

The coordination compounds [CdI2(4-MePy)2] (I) and [CdI2(4-MeQuin)2] (II) where Quin is quinoline have been synthesized, and their structure has been solved. Crystals of complex I are monoclinic, space group C2/c, a = 13.353(1) Å, b = 16.653(1) Å, c = 14.380 (1) Å, β = 103.17(1)°, V = 3113.5(4) Å3, ρcalcd = 2.425 g/cm3, Z = 8. Crystals of complex II are monoclinic, space group P21/c, a = 10.647(1) Å, b = 25.264(1) Å, c = 8.610(1) Å, β = 113.73(1)°, V = 2120.1(3) Å3, ρcalcd = 2.044 g/cm3, Z = 4. Polymer [CdI2(4-MePy)2]∞ chains running in the direction [001] are formed in the structure of complex I. Each of the two crystallographically nonequivalent Cd(1) and Cd(2) atoms are octahedrally surrounded by the four iodine and two nitrogen atoms of the 4-MePy ligand. The Cd(1)⋯Cd(2) distance in a chain is 4.33 Å. The structure of complex II is built of [CdI2(4-MeQuin)2] discrete neutral clusters. The two iodine and two nitrogen atoms of the 4-MeQuin ligand participate in the coordination of the Cd2+ ion. The cadmium coordination polyhedron is a distorted tetrahedron (Cd-Iavg, 2.72 Å; Cd-Navg, 2.30 Å; angles N(I)CdN(I), 98.3–121.8°). The minimum and maximum values correspond to the ICdI angle and NCdN angle, respectively. Complex I is photoluminescent in the solid state at room temperature.

Heterometallic derivatives of dicarbonylcyclopentadienylrhenium disulfide containing chromium pentacarbonyl and bis(triphenylphosphine)platinum

The reaction of Cp′Re(CO)2THF (Cp′ = C5H4Me), THF is tetrahydrofuran) with sulfur affords Cp′Re(CO)2S2(I) and [Cp′Re(CO)2]2S (II). The synthesized compounds are isolated chromatographically and characterized by X-ray diffraction analysis. The adduct Cp′Re(CO)2S2Cr(CO)5 (III) is synthesized by the reaction of compound I with Cr(CO)5(THF). The adduct CpRe(CO)2S2Cr(CO)5 (IV) is obtained similarly from known CpRe(CO)2S2 and Cr(CO)5(THF). The reaction of compound I with (PPh3)2Pt(C2Ph2) results in the removal of Ph2C2 and one sulfur atom to form Cp′Re(CO)2SPt(PPh3)2 (V). The structures of compounds I–V are determined by X-ray diffraction analysis (CIF files CCDC nos. 984554 (I), 984555 (II), 984556 (III), 984557 (IV), and 984558 (V)). Compound I contains the three-membered cycle ReS2 with the ordinary S-S bond (2.044(4) Å) and shortened Re-S bonds (average 2.434(3) Å). The three-membered cycle Re2S containing the ordinary Re-Re bond (2.932(1) Å) and shortened Re-S bonds (2.371(1) Å) is observed in compound II. In compounds III and IV, the formation of the ordinary S-Cr(CO)5 bond (2.406(1) Å) with one of the sulfur atoms almost does not change the geometry of the ReS2 fragment. The thermal decomposition of compound III proceeds with the elimination of six CO ligands in the range 110–160°C and then with the loss of CO and Cp′ in the range 160–430°C and the formation of the inorganic residue ReCrS2. Compound V contains the triangular framework ReSPt with the ordinary Pt-Re bond (2.7882(3) Å) and substantially shortened bonds Re-S (2.3984(9) Å) and Pt-S (2.2724(8) Å). It is assumed that compounds II and V can be presented as products of the π-coordination of the double bonds in Cp′(CO)2Re=S with the Cp′Re(CO)2 or Pt(PPh3)2 groups, respectively.

Synthesis of 4-ethyl-5-ethylimino-[1,2,4]-dithiazolidin-3-trithione through ethyl-(4-ethyl-5-thioxo-[1,2,4]-dithiazolidin-3-ylidene)ammonium oxopentachlorotungstate(VI) hydrolysis and the dimroth rearrangement in it on heating

We demonstrate that the previously synthesized product of ethyl isothiocyanate insertion into tungsten hexachloride, WCl5{N(Et)C(S)N(Et)C(S)Cl}, whose partial hydrolysis yields {N(Et)C(S)-S-S-C=NH(Et)}[WOCl5] (I), can be used as a source of biologically active heterocyclic compounds. 1H and 13C NMR and gas chromatography-mass spectrometry data show that reaction of I with a saturated aqueous Na2CO3 solution yields a number of thiazolidine heterocycles, mostly 4-ethyl-5-ethylimino-[1,2,4]-dithiazolidin-3-trithione. The thermal Dimroth rearrangement leads to the formation of 2,4-diethyl-[1,2,4]-dithiazolidin-3,5-dithione and the products of partial hydrolysis of both heterocycles: 4-ethyl-5-ethylimino-[1,2,4]-dithiazolidin-3-on and 2,4-diethyl-3-thioxo-[1,2,4]-dithiazolidin-5-on.

Structures of silver nitrate complexes with quinolines according to NMR data

Silver(I) nitrate complexes [AgNO3(L)2], where L is quinoline or 2-, 4-, and 8-methylquinoline, are synthesized and studied by the multinuclear NMR (1H, 13C, 15N) method in acetonitrile. The influence of steric and electronic factors of the organic ligand on the NMR spectral parameters is revealed. The fast chemical exchange of the free and coordinated ligands is observed at room temperature. The 15N NMR spectra are most informative. The formation of a complex with 8-methylquinoline is impeded because of steric hindrances.