The decades-old mystery of bis(diethyl ether)tungsten(IV) chloride solved
(Source: Acta Crystallographica Section C)
Source: Acta Crystallographica Section C - March 12, 2021 Category: Chemistry Authors: Sch ä fer, A. Tags: tungsten diethyl ether complex octahedral coordination chemistry commentary scientific commentaries Source Type: research
Variants of the X-phase in the Mn – Co – Ge system
We report two new variants of the X-phase (orthorhombic, space group Pnnm) derived from the Mn – Co – Ge system. Two compositionally related crystals were investigated by means of single-crystal X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). The Mn14.9Co15.5Ge6.6 and Mn14Co16.2Ge6.8 intermetallic compounds are part of the homogeneity region of the X-phase and adopt the Mn14(Mn0.11Co0.64Si0.25)23 structure type. The composition obtained from refinement of the XRD data is in agreement with the EDS results. In the present study, chemical disorder was only detected on the 8h positions. The ordering is co...
Source: Acta Crystallographica Section C - March 9, 2021 Category: Chemistry Authors: Shtender, V. Larsen, S.R. Sahlberg, M. Tags: intermetallic compound crystal structure X-phase Mn-Co-Ge system manganese cobalt germanide research papers Source Type: research
Crystal structure refinements of stoichiometric Ni3Se2 and NiSe
Single crystals of Ni3Se2 (trinickel diselenide) and NiSe (nickel selenide) with stoichiometric chemical compositions were grown in evacuated silica-glass tubes. The chemical compositions of the single crystals of Ni3Se2 and NiSe were determined by scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). The crystal structures of Ni3Se2 [rhombohedral, space group R32, a = 6.02813 (13), c = 7.24883 (16) Å , Z = 3] and NiSe [hexagonal, space group P63/mmc, a = 3.66147 (10), c = 5.35766 (16) Å , Z = 2] were analyzed by single-crystal X-ray diffraction and ref...
Source: Acta Crystallographica Section C - March 9, 2021 Category: Chemistry Authors: Unoki, K. Yoshiasa, A. Kitahara, G. Nishiayama, T. Tokuda, M. Sugiyama, K. Nakatsuka, A. Tags: NiSe Ni3Se2 crystal structure single-domain structure Debye temperature nickel selenide research papers Source Type: research
Syntheses and solid-state structures of two cofacial (bis)dipyrrin dichromium complexes in different charge states
The dichromium Pacman complex (tBudmx)Cr2Cl2 · C4H10O (1) [(tBudmx)H2 is a dimethylxanthene-bridged cofacial (bis)dipyrrin, C49H58N4O] was synthesized by salt metathesis using anhydrous CrCl2 and previously reported (tBudmx)K2. Treatment of 1 with two equivalents of the reductant potassium graphite afforded K2(tBudmx)Cr2Cl2(thf)3 · 0.5C4H10O · 0.5C4H8O (thf is tetrahydrofuran, C4H8O) (2), with both potassium ions intercalated between the pyrrolic subunits. Comparison of the solid-state structures for 1 and 2 reveals minimal changes in the primary coordination sphere of each Cr ion, with notable elongation of the dipyrri...
Source: Acta Crystallographica Section C - February 26, 2021 Category: Chemistry Authors: Carsch, K. Elder, S.E. Dogutan, D.K. Nocera, D.G. Yang, J. Zheng, S.-L. Daniel, T. Betley, T.A. Tags: dipyrrin Pacman compound crystal structure dichromium xanthene research papers Source Type: research
Synthesis and characterization of enantiopure planar – chiral phosphorus-linked diferrocenes
In the course of an ongoing synthetic project on cyclic diferrocenylphosphines, we obtained a group of planar – chiral diferrocenyl compounds useful as precursors for subsequent cyclization. Here we report the crystal structures of two symmetric compounds [(FcA)2(Ph)P], one of which contains four stereogenic centres (two C chiral and two planar chiral centres), i.e. 1,1 ′ -(phenylphosphanediyl)bis{(2Sp)-2-[(1R)-1-(acetyloxy)ethyl]ferrocene}, [Fe2(C5H5)2(C24H25O4P)], and the other phosphine sulfide is a purely planar – chiral compound (two planar chiral centres), i.e. bis[(2Sp)--2-ethenylferrocen-1-yl]phenylphosphane ...
Source: Acta Crystallographica Section C - February 25, 2021 Category: Chemistry Authors: Honegger, P. Roller, A. Widhalm, M. Tags: crystal structure metal organic three-dimensional structure ferrocene phosphine sulfide chirality planar chirality research papers Source Type: research
New node on the block for organic solid-state chemists: rtct-tetrakis(pyridin-4-yl)cyclobutane
(Source: Acta Crystallographica Section C)
Source: Acta Crystallographica Section C - February 25, 2021 Category: Chemistry Authors: Reinheimer, E.W. Tags: crystal engineering hydrogen bonding [2 2] cycloaddition reaction organic solid state interpenetration resorcinol photoproduct topochemical postulate scientific commentaries Source Type: research
(NH4)Mg(HSO4)(SO4)(H2O)2 and NaSc(CrO4)2(H2O)2, two crystal structures comprising kr ö hnkite-type chains, and the temperature-induced phase transition (NH4)Mg(HSO4)(SO4)(H2O)2\rightleftharpoons (NH4)MgH(SO4)2(H2O)2
The crystal structure of the mineral kr ö hnkite, Na2Cu(SO4)2(H2O)2, contains infinite chains composed of [CuO4(OH2)2] octahedra corner-linked with SO4 tetrahedra. Such or similar tetrahedral – octahedral `kr ö hnkite-type' chains are present in the crystal structures of numerous compounds with the composition AnM(XO4)2(H2O)2. The title compounds, (NH4)Mg(HSO4)(SO4)(H2O)2, ammonium magnesium hydrogen sulfate sulfate dihydrate, and NaSc(CrO4)2(H2O)2, sodium scandium bis(chromate) dihydrate, are members of the large family with such kr ö hnkite-type chains. At 100 K, (NH4)Mg(HSO4)(SO4)(H2O)2 has an unprecedented tri...
Source: Acta Crystallographica Section C - February 22, 2021 Category: Chemistry Authors: Weil, M. Kolitsch, U. Tags: ammonium magnesium sulfate strong hydrogen bond sodium scandium chromate tetrahedral-octahedral chains kr ö hnkite-type chains phase transition crystal structure IR spectroscopy research papers Source Type: research
Nitroxide radicals appended to phthalonitriles: synthesis, structural characterization and photophysical properties
The syntheses of 4-[4-(4,4,5,5-tetramethyl-2-imidazoline-3-oxide-1-oxyl-2-yl)phenoxy]phthalonitrile (3, C21H19N4O3) and 4-[4-(4,4,5,5-tetramethyl-2-imidazoline-1-oxyl-2-yl)phenoxy]phthalonitrile (4) were carried out by microwave-assisted nucleophilic aromatic substitution of 4-nitrophthalonitrile (2) by the pre-formed 2-(4-hydroxyphenyl)-4,4,5,5-tetramethyl-2-imidazoline-3-oxide-1-oxyl (1). Compounds 3 and 4 were characterized unambiguously by a rich array of analyses, such as melting point, FT – IR, MALDI – TOF MS, elemental analysis, UV – Vis, CV, EPR, magnetic measurements and single-crystal X-ray diffraction. Str...
Source: Acta Crystallographica Section C - February 22, 2021 Category: Chemistry Authors: Fidan, I. Onal, E. Hirel, C. Tags: phthalonitrile nitronyl nitroxide imino nitroxide crystal structure stable radical EPR spectra redox properties research papers Source Type: research
Structural and theoretical analysis of 2-chloro-4-nitroaniline and 2-methyl-6-nitroaniline salts
The crystal structures of five new salts of 2-chloro-4-nitroaniline (2Cl4na) and 2-methyl-6-nitroaniline (2m6na) with inorganic acids, namely, 2-chloro-4-nitroanilinium bromide, C6H6ClN2O2+ · Br − (1), 2-chloro-4-nitroanilinium hydrogen sulfate, C6H6ClN2O2+ · HSO4 − (2), 2-methyl-6-nitroanilinium bromide, C7H9N2O2+ · Br − (3), 2-methyl-6-nitroanilinium triiodide, C7H9N2O2+ · I3 − (4), and 2-methyl-6-nitroanilinium hydrogen sulfate, C7H9N2O2+ · HSO4 − (5), were determined by single-crystal X-ray diffraction. Theoretical calculations of the relaxed potential energy surface (rPES) revealed that the energy barri...
Source: Acta Crystallographica Section C - February 18, 2021 Category: Chemistry Authors: Medviediev, V. Daszkiewicz, M. Tags: 2-chloro-4-nitroaniline 2-methyl-6-nitroaniline salts crystal structure triiodide rPES nitro interactions research papers Source Type: research
Structural characterization and theoretical calculations of the monohydrate of the 1:2 cocrystal salt formed from acriflavine and 3,5-dinitrobenzoic acid
The synthesis and structural characterization of the monohydrated 1:2 cocrystal salt of acriflavine with 3,5-dinitrobenzoic acid [systematic name: 3,6-diamino-10-methylacridin-10-ium 3,5-dinitrobenzoate – 3,5-dinitrobenzoic acid – water (1/1/1), C14H14N3+ · C7H3N2O6 − · C7H4N2O6 · H2O] are reported. Single-crystal X-ray diffraction measurements show that the title solvated monohydrate salt crystalizes in the monoclinic space group P21 with one acriflavine cation, a 3,5-dinitrobenzoate anion, a 3,5-dinitrobenzoic acid molecule and a water molecule in the asymmetric unit. The neutral and anionic forms of 3,5-dinitro...
Source: Acta Crystallographica Section C - January 27, 2021 Category: Chemistry Authors: Marczak, M. Biereg, K. Zadykowicz, B. Sikorski, A. Tags: acriflavine 3,5-dinitrobenzoic acid cocrystal crystal structure hydrogen bonding nitro group interactions crystal engineering theoretical calculations research papers Source Type: research
Honeycomb molecular network based upon a hydrate of 4,6-dichlororesorcinol and the photoproduct rtct-tetrakis(pyridin-4-yl)cyclobutane
The formation of a self-interpenetrated honeycomb molecular network based upon 4,6-dichlororesorcinol (4,6-diCl res), a water molecule, and the photoproduct rtct-tetrakis(pyridin-4-yl)cyclobutane (rtct-TPCB) is reported. Interestingly, only three of the four pyridine rings on the central cyclobutane ring are found to engage in O — H...N hydrogen bonds with either the 4,6-diCl res or an included water molecule, resulting in a three-connected net. Notably, the solid (4,6-diCl res) · (rtct-TPCB) · (H2O), C6H4Cl2O2 · C24H20N4 · H2O, contains channels that run along the crystallographic b axis, which are found to be inter...
Source: Acta Crystallographica Section C - January 22, 2021 Category: Chemistry Authors: Santana, C.L. Battle, J.D. Unruh, D.K. Groeneman, R.H. Tags: crystal engineering hydrogen bonding [2 2] cycloaddition reaction organic solid state crystal structure interpenetration resorcinol photoproduct research papers Source Type: research
Manganese(II) complexes derived from acyclic ligands having flexible alcohol arms: structural chracterization and SOD and catalase mimetic studies
In this work, a series of seven MnII complexes of noncyclic flexible ligands derived from 2,6-diformylpyridine and ethanolamine or alkyl-substituted ethanolamines were prepared and characterized, six structurally by single-crystal X-ray diffraction studies. The complexes are dichlorido{2,2 ′ -[(pyridine-2,6-diyl)bis(nitrilomethanylylidene)]diethanol}manganese(II), [MnCl2(C11H15N3O2)] or [MnCl2(L1)], (2), bis{ μ -2,2 ′ -[(pyridine-2,6-diyl)bis(nitrilomethanylylidene)]diethanol}bis[dithiocyanatomanganese(II)], [Mn2(NCS)4(C11H15N3O2)2] or [Mn2(NCS)4(L1)2], (3), chlorido{1,1 ′ -[(pyridine-2,6-diyl)bis(nitrilomethanylyli...
Source: Acta Crystallographica Section C - January 18, 2021 Category: Chemistry Authors: McKee, V. Kose, M. Tags: manganese SOD activity catalase mimetic study acyclic ligand superoxide crystal structure research papers Source Type: research
Alkali and alkaline earth coordination polymers constructed from benzene-1,2,4,5-tetracarboxylic acid and flexible dicarboxylate acid ligands: syntheses, structures and spectroscopic and thermal properties
Two new metal coordination complexes, namely, poly[aqua( μ 6-benzene-1,2,4,5-tetracarboxylic acid- κ 8O1:O1,O2:O2 ′ :O4:O4,O5:O5 ′ )( μ -but-2-enedioato- κ 2O1:O4)potassium(I)], [K2(C4H2O4)(C10H6O8)(H2O)2]n or [K2(fum)(H4btec)(H2O)2]n, (1), and poly[aqua( μ 8-2,5-dicarboxybenzene-1,4-dicarboxylato- κ 12O1:O1 ′ ,O2:O2,O2 ′ :O2 ′ :O4:O4 ′ ,O5:O5,O5 ′ :O5 ′ )( μ -ethanedioato- κ 4O1,O2:O1 ′ ,O2 ′ )strontium(II)], [Sr2(C2O4)(C10H4O8)(H2O)2]n or [Sr2(ox)(H2btec)(H2O)2]n, (2) (H4btec = benzene-1,2,4,5-tetracarboxylic acid, H2btec = 2,5-dicarboxybenzene-1,4-dicarboxylate, fum = fumarate and ox = oxalat...
Source: Acta Crystallographica Section C - January 14, 2021 Category: Chemistry Authors: Lifa, S. Trifa, C. Bouacida, S. Boudaren, C. Hocine, M. Tags: alkali alkaline earth metal coordination polymer benzenetetracarboxylic acid crystal structure flexible dicarboxylate ligand topology Hirshfeld surface thermogravimetric analysis DSC analysis MOF research papers Source Type: research
Δ 9-Tetrahydrocannabinolic acid A, the precursor to Δ 9-tetrahydrocannabinol (THC)
While Δ 9-tetrahydrocannabinolic acid A (THCA-A) has been reported to be difficult to crystallize and/or amorphous, we have obtained THCA-A in a pure crystalline form by extraction of marijuana and selective fractionation with liquid CO2. THCA-A (systematic name: 1-hydroxy-6,6,9-trimethyl-3-pentyl-6a,7,8,10a-tetrahydro-6H-benzo[c]isochromene-2-carboxylic acid, C22H30O4) crystallizes in the orthorhombic space group P212121, with Z = 8 and Z ′ = 2. The two independent molecules are related by a pseudo-twofold axis centered between the two – CO2H groups, but the conformations of the two – C5H11 chains are quite d...
Source: Acta Crystallographica Section C - January 14, 2021 Category: Chemistry Authors: Skell, J.M. Kahn, M. Foxman, B.M. Tags: hashish marijuana cannabis THC precursor crystal structure extract fractionation research papers Source Type: research
The structure of Ce2Al3Ge4 refined for the first time from single-crystal X-ray diffraction data
Single crystals of dicerium trialuminium tetragermanide, Ce2Al3Ge4, have been synthesized from a high-temperature reaction using an eutectic mixture of Al and Ge as a metal flux. Through single-crystal X-ray diffraction it was established that Ce2Al3Ge4 crystallizes in the centrosymmetric space group Cmce (No. 64) with the Ba2Cd3Bi4 structure type (Pearson code oC36). Five atoms compose the asymmetric unit, i.e. one Ce, two Al, and two Ge atoms, all in special positions with Wyckoff symbols 8f (Ce), 4a and 8e (Al), and 8e and 8f (Ge). The structure can be described as a three-dimensional network of Al and Ge atoms, with Ce...
Source: Acta Crystallographica Section C - January 14, 2021 Category: Chemistry Authors: Tobash, P. Bobev, S. Tags: lanthanide cerium aluminium germanide crystal structure research papers Source Type: research
