Journal of Chemical Crystallography最新文献

In this paper, we report the crystal and molecular structure of two compounds obtained from the reactions between the ligand 2,4,6-tris(2-pyrimidyl)-1,3,5-triazine (TpymT) with Pd(II) and Pt(II) [M(Cl₂(CH₃CN)₂] complexes. The ligand hydrolyses into the anion N-[(pyrimidine)carbonyl]pyrimidine-2-carboxamidato (bpcam⁻), giving compounds with the formula [Pd(bpcam)Cl]·H₂O, 1, and [Pt(bpcam)Cl]·DMSO, 2. Compounds 1 and 2 crystallize in the monoclinic crystal system with C2/c and P2₁/n space groups. The compounds are square planar, with the bpcam⁻ acting as a tridentate-κ³N anionic ligand and the Cl⁻ anion in the fourth position. In both complexes, the molecules stack in columns presenting interactions between the aromatic rings, reinforced in 2 by Pt···Pt interactions. The complexes interact with the solvent molecules through H-bonds building a 3D structure. We analyzed the systems through geometric parameters and Hirshfeld surface studies. The energy frameworks indicate that the main interactions between molecules in the crystal are dispersion forces.

Graphical Abstract

The paper presents the X-ray structures of [M(bpcam)Cl]·where bdcam- is the anion N-[(pyrimidine)carbonyl]pyrimidine-2-carboxamidato and M = Pd(II) and Pt(II), as well as Hirshfeld Surface and Energy Framework studies.

Two novel taxoids were synthesized from 1-deoxybacctin VI (1) and their crystal structures were determined by X-ray crystallographic techniques. The influence of the 11,12-olefin of the tetracyclic moiety on molecular conformations were investigated. Comparison to other baccatin analogs, a larger effect on the conformation of the diterpenoid core is observed when the 11,12-olefin is reducted. Conformational analysis show that the reduction of the 11,12-olefin has a decisive influence on the conformation of the A and B ring. Compounds 3 and 5 crystallize in orthorhombic system, space group P2₁2₁2₁. In the structure of compound 3, the six-membered A ring exhibits the 1,3-diplanar boat conformation, the eight-membered B ring adopts a boat–chair conformation, and the six-membered C ring exhibits a slightly distorted half-chair conformation. However, in 11,12-dihydro-taxoids 5, the six-membered A ring exhibits a chair conformation and the conformation of the eightmembered B ring has a large distortion.

Graphical Abstract

The synthesis of novel 11,12-dihydro-taxoids from 1-deoxybacctin VI are presented, in which the crystal structure of the compound 5 was characterized.

Five years after we published the synthesis of the first diamidocarbene (DAC)-supported amino borylene 4, we now report the elusive single crystal X-ray structure. The X-ray structure of 4 was found to corroborate our previous computational studies which indicated that the borylene adopted a heterocumulenic geometry with a near linear C_(carbene) = B = N unit (175.88(18)^◦) as well as short C = B and B = N distances of 1.416(3) and 1.344(3) Å, respectively. Additionally, we further provide a qualitative and quantitative discourse on said structure with respect to the precursor compounds used to prepare 4 as well as to the known cyclic (alkyl) amino carbene (CAAC) analog 2.

Two bismuth(III) coordination polymers, namely [Bi₂X₆(µ-dtpo)₃]_n [X = Cl (1), Br (2); dtpo = 2,2′-dithiobis(pyridine N-oxide)], were prepared using a crystal engineering strategy and structurally characterized by X-ray crystallography. In the isostructural compounds 1 and 2 (trigonal system, space group P-3c1), fac-configured BiX₃ units as nodes are joined by the C₂-symmetrical dtpo bridging ligand as spacers to generate 2D honeycomb layers with (6,3) topology. The 2D sheets stack along the [001] direction, resulting in virtually hexagonal channels parallel to this direction, which are occupied by disordered methanol and water molecules. The potential solvent area per unit cell volume is 42.2% for 1 and 44.0% for 2.

Graphical Abstract

Two isostructural 2D honeycomb bismuth(III) coordination, synthesized from 2,2′-dithiobis(pyridine N-oxide) and bismuth(III) halides are described.

Crystals of Sodium Laurate, Lauric Acid (NaLLA) were obtained and the structure was determined by single-crystal X-ray diffraction. The new crystal form is monoclinic of space group P2₁/c. The asymmetric unit contains two independent laurate molecules whose carboxylic/carboxylate groups are linked by a low barrier O-H…O hydrogen bond. Two lauric/laurate molecules are in a head-to-head configuration and the elongated hydrophobic chains are parallel to the long b axis. The carboxylic hydrogen atom was found to be disordered, bound on each of the two carboxylate groups in an unsymmetrical way. The non-symmetrical character of the hydrogen bond is related to the presence of two independent fatty acid molecules in the asymmetric unit and is in accordance with the different lengths of the four C-O bonds present in the molecular structure. The crystal structure was analyzed in terms of interactions on the Hirshfeld surface. The packing is stabilized by hydrogen bonds and O…Na ionic interactions in the hydrophilic layer and by C-H…H-C contacts in the hydrophobic layers which are the most enriched major contacts.

New hydrazone derivate, (1Z,2E)-2-(2-(1-(1,3-dimethyl-2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene)ethyl)hydrazineylidene)-2-(p-tolyl)acetaldehyde oxime (H₂L) was synthesized by 5-acetyl-1,3-dimethyl-barbituric acid and p-methyl isonitrosophenylhydrazine. Its molecular and crystal structures were determined by single crystal X-ray analysis. It belongs to triclinic system P-1 space group with a = 7.1722 (3) Å, b = 10.5362 (4) Å, c = 11.7675 (5) Å, α = 98.844 (4)°, β = 98.882 (4)°, γ = 104.330 (4)°, Z = 2 and V = 833.95 (6) ų. In the molecular structure, the intramolecular N–H···O and N–H···N hydrogen bonds enclose S(6) ring motifs. In the crystal structure, the intermolecular C–H···O and O–H···O hydrogen bonds link the molecules into centrosymmetric dimers, enclosing R₂²(10) and R₄⁴(10) ring motifs, in which they may be effective in stabilization of the structure. The Hirshfeld surface analysis of crystal structure indicates that the most important contributions for crystal packing are from H…H (48.5%), H…O/O…H (23.7%) and H…C/C…H (9.7%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in crystal packing. Computational chemistry indicates that in the crystal, O–H···O and C–H···O hydrogen bond energies are 95.9 and 87.5 kJ mol⁻¹. The evaluation of the electrostatic, dispersion and total energy frameworks indicates that stabilization is dominated via the nearly equal strengths of the electrostatic and dispersion energy contributions.

Graphical Abstract

A new hexavanadate hybrid with alkynyl ligands (DIEA)₂[V₆O₁₃{(OCH₂)₃CNHCOC₆H₄C≡CH}₂] was synthesized and its molecular structure has been determined by single-crystal X-ray diffraction. The compound crystallize in the orthorhombic system, space group Pccn with the cell parameters a = 15.951(2) Å, b = 33.240 Å, c = 10.5960(14) Å, α = β = γ = 90°, V = 5618.2(13) Å ³. The electrostatic potential was also calculated to show the electron distribution in the polyoxoanion.

Graphical Abstract

A new hexavanadate hybrid with alkynyl ligands (DIEA)₂ [V₆O₁₃{(OCH₂)₃CNHCOC₆H₄C≡CH}₂] was synthesized by post-functionalization. Each of the structures looks like a flabellum and both ends are straight and rigid on account of the conjugated effect in the organic ligands.

Mononuclear uranyl(VI) Schiff base complexes of formula [UO₂(L₁)]·py (1·py) {[UO₂(L²)]}₂·MeCN·H₂O (2·MeCN·H₂O) have been prepared and characterized by both IR and ¹H NMR spectroscopy and X-ray crystallography. The complex species 1·py crystallizes as orange needle-like crystals in the orthorhombic space group, Pbca, with 8 molecules per unit cell. Interestingly, the pyridine molecule does not participate in coordination to the metal center and was found as a solvent molecule embedded in the crystal structure with weaker interactions to the metal complex. The crystals of the complex species, 2·MeCN·H₂O, crystallized in a monoclinic form, space group, P2₁, with 2 molecules in the asymmetric unit. The two molecules [(UO₂)(L₂)(CH₃CN or H₂O)] in the asymmetric unit of 2·MeCN·H₂O exhibit a competitive (CH₃CN/H₂O) scenario without any direct coordination to the uranyl ion.

Graphical Abstract

Uranyl(VI) Schiff base complexes of general formula [UO₂(L₁)]·py (1·py) and {[UO₂(L²)]}₂·MeCN·H₂O (2·MeCN·H₂O) have been prepared and characterized by spectroscopic analysis and X-ray crystallography.

Treatment of diphenyl tellurium oxide (Ph₂TeO) with CuCl₂·2H₂O in a 4:1 molar ratio afforded the copper(II) complex [Cu^II(Ph₂TeO)₄]Cl₂·14H₂O (1), in which the copper(II) center is four-coordinated by four oxygen atoms from four Ph₂TeO units. Reaction of MnCl₂·4H₂O, (ⁿBu₄N)[MnO₄] and Ph₂TeO at a molar ratio of 4:1:16 gave the manganese(III) complex [Mn^IIICl(Ph₂TeO)₄]Cl₂·4H₂O (2), in which the manganese(III) center is five-coordinated by one chlorine atom and four oxygen atoms from four Ph₂TeO moieties. Complex 1 crystallizes in the triclinic space group Pī, with a = 8.9904(18), b = 13.068(3), c = 13.573(3) Å, α = 100.42(3)°, β = 109.17(3)°, γ = 99.56(3)°, and Z = 1. The unit cell of 2 has a monoclinic P2₁/c symmetry with the cell parameters a = 20.179(5), b = 13.917(3), c = 19.210(4) Å, β  =  94.840(7)°, and Z = 4.

Graphical Abstract

Two new transition metal complexes with diphenyl tellurium oxide as ligands have been synthesized and studied.