A. V. Tkachev

Synthesis and photoluminescence of the chiral compounds [ZnLCl2] · EtOH and ZnLCl2, where L is the (+)-3-Carene derivative containing pyrazoline and quinoline fragments: crystal structure of [ZnLCl2] · EtOH

The following chiral compounds were synthesized: [ZnLCl2] · EtOH (I) and ZnLCl2 (II), where L is the pyrazolin-5-ol derivative obtained from terpene (+)-3-carene. According to the X-ray diffraction data, the crystal structure of compound I is built of acentric molecules of the mononuclear ZnLCl2 complex and EtOH molecules. In molecules of the complex, the Zn2+ ion is coordinated by two N atoms of the bidentate chelating ligand L and two Cl atoms at the vertices of the distorted tetrahedron. The intermolecular contacts and the hydrogen bonds Cl(1)…H-O(1) between the adjacent ZnLCl2 molecules result in the formation of chains parallel to the y axis. The reactant L and solvate I possess weak photoluminescence in the visible spectral range. Complex II exhibits more intense photoluminescence at λmax = 416 and 517 nm.

Reactions of N,N-(dialkyl)arylthioacetamides with dialkyl acetylenedicarboxylates

Abstract2-(Alkoxycarbonylmethylidene)-4-aryl-5-(dialkylamino)thiophen-3(2H)-ones were synthesized by condensation of N,N-(dialkyl)arylthioacetamides with dialkyl acetylenedicarboxylates. Intermediate substituted vinylic sulfides were isolated. When heated or in the presence of an acid or a base, they undergo cyclization into thiophenes.

Binuclear Pd(II) complexes with chiral ethylenediaminodioxime (H2L) and bis-α-thiooxime (H2L1), the derivative of monoterpenoid(+)-3-carene. Crystal structures of [Pd2(H2L)Cl4] and [Pd2(H2L1)Cl4] · 3CDCl3

Diamagnetic Pd(II) complexes with the chiral ethylenediaminodioxime (H 2 L) and bis-α-thiooxime (H2L1), the derivatives of monoterpenoid (+)-3-carene, of the composition Pd2(H2L)Cl4(I), Pd2(H2L1)Cl4 (II), and the solvate Pd2(H2L1)Cl4·3DCl3 (III) were synthesized. The crystal structures of complex I and solvate III were determined from X-ray diffraction data. The structures consist of acentric binuclear molecules with the coordination cores PdN2Cl2 (in I) and PdNSCl2 (in III) in the form of the distorted squares. In complex I, each Pd atom coordinates two N atoms of the tetradentate bridge-cyclic ligand H2L and two Cl atoms; in compound III, one N and one S atom of the tetradentate bridge-cyclic ligand H2L1, and 2 Cl atoms. The CDCl3 molecules in compound III lie in the cavities formed by the molecules of complex II. In both structures, the PdCl2 fragments are in the trans-positions. The 1H NMR spectra indicate that the structures of complexes I, II in solutions are similar to the structures of compounds I, III in the solid state.

Synthesis of binuclear complexes of PdCl2 with chiral α,α′-diamino-meta-xylene dioximes H2L1, H2L2, and H2L3, the derivatives of the terpenes (+)-3-carene, (R)-(+)-limonene, and (S)-(−)-α-pinene. Crystal structure of [Pd2(H2L1)Cl4]

Chiral α,α′-diamino-meta-xylene dioximes H2L1, H2L2, and H2L3 were obtained from the naturally occurring terpenoids (+)-3-carene, (R)-(+)-limonene, and (S)-(−)-α-pinene, respectively. Reactions of these ligands with PdCl2 gave the diamagnetic complexes Pd2(H2L1)Cl4 (I), Pd2(H2L2)Cl4 (II), and Pd2(H2L3)Cl4 (III). According to X-ray diffraction data, the crystal structure of complex I consists of acentric binuclear molecules [Pd2(H2L1)Cl4]. The coordination polyhedron PdN2Cl2 is a square distorted in a tetrahedral manner (trapezium) made up of two N atoms of the tetradentate bridging cyclic ligand H2L1 and two Cl atoms. The fragments PdCl2 in the complex are cis to each other. According to the 1H NMR spectra of complexes I–III in CDCl3, the organic ligands are coordinated through the N atoms; in solution, the complexes exist in several forms.

Crystal structure of solvate [Cd2L2Cl4]·CH2Cl2 (L = pyrazolylquinoline, the derivative of monoterpenoid (+)-3-carene) and photoluminescence of chiral complex CdLCl2

Using the single crystal X-ray diffraction data (150 K, Bruker X8 Apex CCD autodiffractometer, MoKα radiation), the crystal structure of the [Cd2L2Cl4]·CH2Cl2 (L = pyrazolylquinoline, the derivative of monoterpenoid (+)-3-carene) compound is determined. Crystals are monoclinic, unit cell parameters are: a = 10.7005(4) Å, b = 16.8491(4) Å, c = 11.9658(4) Å, β = 93.308(1)°, P21 space group. The structure is formed from discrete acentric molecules of a binuclear [Cd2L2Cl4] complex and uncoordinated CH2Cl2 molecules. The Cd2+ ions coordinate N atoms of bidentate chelating ligands L, which leads to the closure of two five-membered chelate CdN3C rings. The coordination sphere of Cd atoms also includes three Cl atoms (two bridging and one terminal), consequently, two CdCl3N2 coordination sites and a Cd2Cl2 metal ring are formed. The Cl3N2 polyhedra have the form of distorted tetragonal pyramids. The CH2Cl2 molecules located in the channels formed by the complexes are linked with them by weak H-bonds. The excitation spectra of L and the CdLCl2 compound contain bands with λmax of 352 nm and 360 nm respectively. At 300 K and λexcit 350 nm, in the photoluminescence spectrum of L a rather intense broad split band with λmax 372 nm and 386 nm is observed. The photoluminescence spectrum of the CdLCl2 compound contains a broad band with λmax 418 nm. The photoluminescence intensity of this compound is significantly lower than that of L.

Synthesis of binuclear complexes of PdCl2 with chiral ethylenediamine dioxime (H2L1), piperazine dioxime (H2L2), and propylenediamine dioxime (H2L3), the derivatives of the natural monoterpenoid (R)-(+)-limonene. The crystal structures of [Pd2(H2L1)Cl4] and [Pd2(H2L2)Cl4]

The diamagnetic complexes [Pd2(H2L1)Cl4] (I), [Pd2(H2L2)Cl4] (II), and Pd2(H2L3)Cl4(III) with chiral ligands derived from the natural monoterpenoid (R)-(+)-limonene are obtained (H2 L1 is ethylenediamine dioxime, H2L2 is piperazine dioxime, and H2L3 is propylenediamine dioxime). According to X-ray diffraction data, the crystal structures of complexes I and II are composed of binuclear acentric molecules. The coordination polyhedra PdN2Cl2 are trapeziums (squares distorted in a tetrahedral manner) made up of two N atoms of the tetradentate bridging cyclic ligands H2L1 and H2L2 and two Cl atoms. The fragments PdCl2 are trans in the complexes. The 13C and 1H NMR spectra of complexes I and II in CDCl3 also suggest their binuclear structures.

Synthesis and structure of Cu(II) and Pd(II) coordination compounds with chiral α-thiooxime, a derivative of natural terpenoid (−)-α-pinene

The paramagnetic complex Cu(HL)Cl2(I) (μeff = 1.88 μB) and the diamagnetic complex Pd(HL)Cl2(II) with chiral α-thiooxime, a derivative of natural terpenoid (−)-α-pinene (HL), were synthesized. The crystal structures of these complexes were determined from single-crystal X-ray diffraction data (X8 APEX diffractometer, MoKα radiation, 2975 Fhkl, R = 0.0258 for I and 3270 Fhkl, R = 0.0222 for II). The crystals of complex I are monoclinic, a = 9.3376(3) Å, b = 6.8619(2) Å, c = 14.6540(5) Å, β = 97.814(1)°, V = 930.22(5) Å3, Z = 2, ρcalc = 1.513 g/cm3, space group P21. The crystals of complex II are orthorhombic, a = 7.0084(6) Å, b = 9.2113(9) Å, c = 29.081(3) Å, V = 1877.4(3) Å3, Z = 4, ρcalc = 1.651 g/cm3, space group P212121. The structures are composed of mononuclear molecules. The coordination cores MNSCl2 (M = Cu, Pd) are tetrahedrally distorted squares. According to NMR data, complex II has a similar structure in a CDCl3 solution. The intermolecular contacts in structure I generate supramolecular polymeric ribbons lying parallel to axis b. No short intermolecular contacts are present in complex II.

Copper(II) and silver(I) complexes with chiral N-substituted aminoacetic acid derivatives containing the natural monoterpenes (+)-3-carene and (–)-α-pinene: Synthesis and structures

The complexes [Cu(HL)Cl] · 0.25H2O (I), [Cu(HL1)Cl] · 0.5H2O (II), [Ag(HL)] · 0.5H2O (III) were obtained; HL– and (HL1)– are the anions of the chiral N-substituted aminoacetic acid derivatives containing the natural monoterpenes (+)-3-carene and (–)-α-pinene, respectively. The µeff values for paramagnetic complexes I and II are 1.92 and 1.81 µB, respectively. Single crystals of the coordination 1D polymer [Cu(HL)Cl · 2H2O]n (IV) were grown. According to the X-ray diffraction data (CIF file CCDC No. 1035219), the crystal structure of complex IV is made up of the zigzag chains [Cu(HL)Cl]n and water molecules. The coordination polyhedron of the Cu atom is a distorted square pyramid (ClN2O2). The anion HL– acts as a chelating and bridging tetradentate ligand coordinated through the N atoms of the NH and NOH groups as well as through the O atoms of the COO–groups linking two adjacent Cu atoms together. The IR spectra of complexes I and II also provide evidence for the coordination of the functional COO–, NOH, and NH groups. In complex III, the coordination sphere of the Ag atom is made up of the O atoms of the COO–group. Complex III shows weak green photoluminescence (λmax = 530 nm).

Synthesis of solvates of the copper(II) complex with chiral caryophyllane-type morpholino oxime (HL). Structure of Cu(HL)Cl2 · CHCl3

Paramagnetic Cu(HL)Cl2 · 0.25CHCl3 (I) and Cu(HL)C12 · 0.25CH2C12 (II), where HL is the optically active morpholino oxime obtained from the terpenoid caryophyllene, were synthesized. The crystals of Cu(HL)Cl2 · CHCl3 (III) were isolated. According to X-ray diffraction data, the crystals of III are composed of acentric mononuclear complex molecules Cu(HL)Cl2 and solvate molecules CHCl3. In the complex molecules, the Cu ion coordinates two N atoms of the bidentate chelating ligand HL and two C1 atoms at the vertices of a distorted tetrahedron. The translationally identical molecules of the complex combined by H-bonds form chains along the axis x.

Synthesis of Pd(II) complexes containing the protonated form or molecule of 2-(3,5-dimethylpyrazol-1-yl)-4-methylquinoline (L). The crystal structure of [Pd(HL)Cl3]

The diamagnetic complexes [Pd(HL)Cl3](I) and PdLCl2(II), where L is 2-(3,5-dimethylpyrazol-1-yl)-4-methylquinoline, were obtained. According to X-ray diffraction data, the crystal structure of complex I consists of mononuclear acentric molecules. The coordination polygon PdNCl3 is a distorted square (trapezium) made up of the pyrazole N atom of the monodentate ligand (cation HL+) and three Cl atoms. Complex II seems to contain the square polygon PdN2Cl2.