Reactions of the stable bis(amino)silylene Si[{N(CH2tBu)}2C6H4-1,2] with group 3 or lanthanide metal organic compounds. Crystal structures of [Ln(η5-C5H5)3Si{[N(CH2tBu)]2C6H4-1,2}]·C7H8 (Ln = Y or Yb)

2000 ◽  
Vol 78 (11) ◽  
pp. 1484-1490 ◽  
Author(s):  
Xiaoping Cai ◽  
Barbara Gehrhus ◽  
Peter B Hitchcock ◽  
Michael F Lappert
Keyword(s):  
Variable Temperature ◽  
Organometallic Complexes ◽  
Monoclinic Space Group ◽  
Apical Position ◽  
Space Group ◽  
X Ray Crystallography ◽  
Metal Organic ◽  
Lanthanide Metal ◽  
Group 3 ◽  
Silylene Complexes

Treatment of the thermally stable aminosilylene Si[{N(CH2tBu)}2C6H4-1,2] [= Si(NN)] with a tris(cyclopentadienyl)- group 3 or -lanthanide metal compound LnCp3 (Cp = η5-C5H5 and Ln = Y or Yb) in toluene at ambient temperature afforded the first earliest transition or f-block metal-silylene complexes [LnCp3{Si(NN)}]·C7H8 (Ln = Y (1) or Yb (2)), characterized by NMR spectroscopy and X-ray crystallography: complex 1 (monoclinic, space group P21/c (no. 14), a = 15.641(5), b = 15.895(7), c = 14.876(5) Å, β = 112.93(3), Z = 4, R1 = 0.067 for 6194 observed data), and2 (monoclinic, space group P21/c (no. 14), a = 15.635(3), b = 15.795(2), c = 14.842(2) Å, β = 112.87(2), Z = 4, R1 = 0.044 for 9829 observed data). The Ln atom in each of the isoleptic complexes 1 and 2 has distorted trigonal monopyramidal geometry, with the approximately trigonal silicon atom in the apical position. The Ln-Si bond length is 3.038(2) (1) or 2.984(2) Å (2). Variable temperature 29Si{1H} NMR spectra in toluene-d8 show that each complex readily dissociates (Y > Yb) into its factors; at 188 K, the 29Si{1H} signal for (1) was a doublet centred at δ 119.5, 1J(29Si-89Y) = 59 Hz.Key words: crystallography, NMR, silylene, yttrium, ytterbium, organometallic complexes.

Supramoleküle aus Kronenethern und geminalen Sulfonen: Synthese von vier binären Komplexen und Kristallstruktur von (CH2CH2O)4·2H 2C(SO2C2H5)2/Supramolecules of Crown Ethers with Geminal Sulfones: Synthesis of Four Binary Complexes and Crystal Structure of (CH2CH2O )4·2H2C(SO2C2H5)2

1995 ◽  
Vol 50 (7) ◽  
pp. 1018-1024 ◽  
Author(s):  
Axel Michalides ◽  
Dagmar Henschel ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Monoclinic Space Group ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Binary Complexes ◽  
Cyclic Polyethers ◽  
Adjacent Unit ◽  
Methylene Group

In a systematic search for supramolecular complexes involving all combinations of the cyclic polyethers 12-crown-4 (12C4), 15-crown-5 (15C 5), 18-crown-6 (18C 6) and dibenzo- 18-crown-6 (DB -18C6), and the geminal di- or trisulfones H2C(SO 2Me)2, H2C (SO2Et)2 and HC (SO2Me)3-n (SO2Et)n (n = 0 -3 ) , only the following four complexes could be isolated and unequivocally characterized by elemental analysis and 1H NMR spectroscopy: [(12C4){H2C (SO2Et)2}2] (3), [(18C6){H2C (S O2Me)2}] (4), [(DB -18C 6){H2C (SO2Et)2}] (5) and [(D B -18C 6)2{HC (SO2Me )(SO2Et)2}3] (6). The structure of 3 (triclinic, space group P1̄) consists of crystallographically centrosymmetric formula units, in which the disulfone molecules are bonded on each side of the ring by two C -H ··· O(crown) interactions originating from the central methylene group (H···O 213 pm) and from the methylene group of one EtSO2 moiety ( H ··· O 237 pm). Formula units related by translation are connected into parallel strands by a third type of reciprocal C -H ···O bond (H ···O 232 pm) between the second H atom of the central methylene group and a sulfonyl oxygen atom of the adjacent unit. The structure of 4 (monoclinic, space group C2/c) showed severe disorder of the crown ether and could not be refined satisfactorily. Compounds 5 and 6 crystallized as long and extremely thin fibres, indicative of linear-polymeric supramolecular structures; single crystals for X-ray crystallography were not available.

Anion-directed assembly of lanthanide coordination polymers with SMMs properties based on a dihydrazone ligand

2018 ◽  
Vol 233 (1) ◽  
pp. 51-59
Author(s):  
Lina Zhang ◽  
Peigao Duan ◽  
Yang Liu ◽  
Jingxian Sun ◽  
Dan Zhao ◽  
...  
Keyword(s):  
Coordination Polymers ◽  
Single Molecule ◽  
Variable Temperature ◽  
Ac Susceptibility ◽  
Directed Assembly ◽  
Magnetization Measurement ◽  
Vital Role ◽  
Diffusion Method ◽  
Monoclinic Space Group ◽  
Space Group

AbstractFour new Ln(III)-based coordination polymers (CPs), [Eu(HL)Cl2(DMF)2]·(H2L) (1), [Dy(HL)Cl2(DMF)2]·(H2L) (2), [Er(HL)Cl2(DMF)(CH3OH)]·(DMF) (3) and [Yb(HL)Cl2(DMF)(H2O)]·(DMF) (4) (H2L=2,6-bis[(3-methoxysalicylidene)hydrazinocarbonyl]pyridine) have been synthesized through the reaction of Ln(III) chloride and H2L by using the vapour diffusion method. Interestingly, Cl−as a template agent plays a vital role in the formation of the target complexes. Single-crystal X-ray diffraction studies indicate that1and2are isostructural and crystallize in triclinic space groupP1̅, while complexes3and4are isostructural and crystallize in monoclinic space groupC2/c. Variable temperature magnetization measurement (χMT–T) demonstrates possible antiferromagnetic interactions in complex2. Alternating-current (ac) susceptibility measurement furthermore indicated frequency dependence for both the in-phase (χ′) and out-of-phase (χ″) components in2, suggesting that there is a slow relaxation behavior of the magnetization, which is typical of single-molecule magnets (SMMs). This is the first time that Ln(III) CPs based on such a dihydrazone ligand has been reported so far.

Crystallographic characterization of three cathinone hydrochlorides new on the NPS market: 1-(4-methylphenyl)-2-(pyrrolidin-1-yl)hexan-1-one (4-MPHP), 4-methyl-1-phenyl-2-(pyrrolidin-1-yl)pentan-1-one (α-PiHP) and 2-(methylamino)-1-(4-methylphenyl)pentan-1-one (4-MPD)

2022 ◽  
Vol 78 (1) ◽  
Author(s):  
Marcin Rojkiewicz ◽  
Piotr Kuś ◽  
Maria Książek ◽  
Joachim Kusz
Keyword(s):  
Chemical Structure ◽  
Crystallographic Data ◽  
New Psychoactive Substances ◽  
Monoclinic Space Group ◽  
Psychoactive Substances ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Analytical Laboratories

Cathinones belong to a group of compounds of great interest in the new psychoactive substances (NPS) market. Constant changes to the chemical structure made by the producers of these compounds require a quick reaction from analytical laboratories in ascertaining their characteristics. In this article, three cathinone derivatives were characterized by X-ray crystallography. The investigated compounds were confirmed as: 1-[1-(4-methylphenyl)-1-oxohexan-2-yl]pyrrolidin-1-ium chloride (1, C17H26NO+·Cl−, the hydrochloride of 4-MPHP), 1-(4-methyl-1-oxo-1-phenylpentan-2-yl)pyrrolidin-1-ium chloride (2; C16H24NO+·Cl−, the hydrochloride of α-PiHP) and methyl[1-(4-methylphenyl)-1-oxopentan-2-yl]azanium chloride (3; C13H20NO+·Cl−, the hydrochloride of 4-MPD). All the salts crystallize in a monoclinic space group: 1 and 2 in P21/c, and 3 in P21/n. To the best of our knowledge, this study provides the first detailed and comprehensive crystallographic data on salts 1–3.

scholarly journals A variable-temperature study of a phase transition in barbituric acid dihydrate

2005 ◽  
Vol 61 (4) ◽  
pp. 464-472 ◽  
Author(s):  
Gary S. Nichol ◽  
William Clegg
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Barbituric Acid ◽  
Crystal Packing ◽  
Variable Temperature ◽  
Mirror Plane ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Acta Cryst ◽  
Space Group

The crystal structure of barbituric acid dihydrate (C4H4N2O3·2H2O) has twice been reported as orthorhombic, space group Pnma, with all atoms (except for CH2 H atoms) lying on the mirror plane [Al-Karaghouli et al. (1977). Acta Cryst. B33, 1655–1660; Jeffrey et al. (1961). Acta Cryst. 14, 881–887]. The present study has found that at low temperatures, below 200 K, the crystal structure is no longer orthorhombic but is non-merohedrally twinned monoclinic, space group P21/n. This phase is stable down to 100 K. Above 220 K the crystal structure is orthorhombic, and between 200 and 220 K the structure undergoes a phase change, with the monoclinic-to-orthorhombic phase transition itself taking place at around 216–217 K. The size of the β angle in the monoclinic structure is temperature dependent; at 100 K β is around 94° and it decreases in magnitude towards 90° as the temperature increases. Although the hydrogen-bonding motifs are the same for both crystal systems, there are significant differences in the crystal packing, in particular the out-of-plane displacement of the two water molecules and the sp 3-hybridized C atom of barbituric acid.

The preparation and X-ray crystal structure of Te(N3)3SbF6 containing the triazidotellurium(IV) cation, Te(N3)3+

1989 ◽  
Vol 67 (11) ◽  
pp. 1687-1692 ◽  
Author(s):  
James P. Johnson ◽  
Gregory K. MacLean ◽  
Jack Passmore ◽  
Peter S. White
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Bond Angles ◽  
X Ray Crystallography ◽  
Distorted Octahedral ◽  
Average Bond

The crystal structure of Te(N3)3SbF6 containing the first binary tellurium–nitrogen cation, triazidotellurium(IV) (Te(N3)3+), has been determined by X-ray crystallography. Single crystals of Te(N3)3SbF6 are monoclinic, space group P21/c with a = 9.201(6), b = 8.445(4), c = 13.582(7) Å, β = 100.36(5)°, Z = 4, final R1 = 0.036 for 1286 observed reflections. The structure consists of discrete Te(N3)3+ cations and distorted octahedral SbF6− anions, with some cation–anion interactions. The average Te—Nα—Nβ—Nγ bond distances in Te(N3)3+ are Te—Nα, 1.994(7); Nα—Nβ, 1.237(11); and Nβ—Nγ, 1.116(12) Å. The average bond angles about the Te, Nα, and Nβ atoms are 94.1(3)°, 116.5(6)°, and 173.7(9)°. Structural correlations with other TeX3+ species have yielded an estimate of the electronegativity of the N3− group to be 3.1 ± 0.1. Keywords: tetratellurium (2+) cation, triazidotellurium(IV) cation, electronegativity, azide.

Metal-selenolate chemistry: stereochemistry of adamantane-type clusters of formula [(μ-SePh)6(MSePh)4]2− (M = Zn and Cd)

1992 ◽  
Vol 70 (3) ◽  
pp. 792-801 ◽  
Author(s):  
Jagadese J. Vittal ◽  
Philip A. W. Dean ◽  
Nicholas C. Payne
Keyword(s):  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Bridging Ligands ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Space Groups ◽  
X Ray Crystallography ◽  
Cell Dimensions ◽  
Minimum Number

The structures of three tetramethylammonium salts containing anions of formula [(μ-SePh)6(MSePh)4]2− (M = Zn and Cd) were determined by single crystal X-ray diffraction techniques. The Zn salt crystallizes in different space groups depending upon the solvent combination used in the synthesis. Thus crystals of (Me4N)2[Zn4(SePh)10], 1, grown from a mixture of methanol, acetonitrile, and acetone are triclinic, space group [Formula: see text] with cell dimensions a = 13.214(2), b = 23.859(2), c = 13.072(1) Å, α = 91.134(8), β = 113.350(8), γ = 79.865(9)°, and Z = 2. In the absence of acetone, a solvated crystal (Me4N)2[Zn4(SePh)10]•CH3CN, 2, is formed, which belongs to the monoclinic space group P21/n with a = 14.248(1), b = 39.722(2), c = 13.408(1) Å, β = 97.132(5)°, and Z = 4. The Cd salt (Me4N)2[Cd4(SePh)10], 3, crystallizes in the monoclinic space group P21/c, with a = 20.830(2), b = 14.282(1), c = 25.872(1) Å, β = 99.626(6)°, and Z = 4. These three salts are the first examples of homoleptic, tetranuclear selenolatometal(II) anions with (μ-Se)6M4 cages of adamantane-type stereochemistry. In each case the phenyl substituents of the bridging ligands adopt the configuration [aae, aae, aee, aee], which has the minimum number of two 1,3-axial–axial non-bonding substituent interactions. Keywords: selenolate complexes, synthesis, X-ray crystallography, isomerism, adamantane stereochemistry.

Quinoxaline-1,2,3-dithiazolyls — Synthesis, EPR characterization, and redox chemistry

2001 ◽  
Vol 79 (9) ◽  
pp. 1352-1359
Author(s):  
A Wallace Cordes ◽  
James R Mingie ◽  
Richard T Oakley ◽  
Robert W Reed ◽  
Hongzhou Zhang
Keyword(s):  
Epr Spectroscopy ◽  
Ring Closure ◽  
Coupling Constants ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Molecular Conductors ◽  
Vacuum Sublimation ◽  
Space Group ◽  
X Ray Crystallography ◽  
Sulfenyl Chlorides

Oxidation of quinoxalineaminothiol with SCl2 or S2Cl2/Cl2 affords a series of compounds based on the quinoxaline-1,2,3-dithiazole framework QDTA. Under highly oxidizing conditions, the 1,2,3-dithiazolyl ring is opened to afford the acyclic dichlorosulfimino-sulfenyl chlorides Clx-QDTA-Cl3 (x = 0, 1, 2). Reduction of these "trichloro" compounds leads to ring closure. For x = 2, reduction using S2Cl2 affords the dithiazolylium chloride [Cl2-QDTA][Cl]. For all values of x, reduction with iodide ion (3 mol equiv) affords the corresponding dithiazolyl radical [Clx-QDTA]. The radicals can be isolated in good yield in crude form, but attempts to purify them by vacuum sublimation lead to thermal degradation. The radicals have nonetheless been fully characterized by EPR spectroscopy, and the assignments of the observed hyperfine coupling constants cross-matched with those obtained by computation at the B3LYP/6-31G** level. The structures of the trichloro compounds Clx-QDTA-Cl3 (x = 1, 2) have been confirmed by X-ray crystallography. Crystal data: Cl-QDTA-Cl3, monoclinic, space group C2/c, a = 30.561(5) Å, b = 4.9764(9) Å, c = 22.247(4) Å, β = 131.822(14)°, V = 2521.4(8) Å3, Z = 8, R(F) = 0.043, and Rw(F) [I [Formula: see text] σ (I)] = 0.049; Cl2-QDTA-Cl3, orthorhombic, space group Pnma, a = 18.627(12) Å, b = 6.848(4) Å, c = 10.926(7) Å, V = 1393.7(15) Å3, Z = 4, R(F) = 0.047, and Rw(F) [I [Formula: see text] 3σ(I)] = 0.060.Key words: thiazyl radicals, molecular conductors, EPR spectroscopy, quinoxaline, DFT calculations.

Synthese Und Kristallstrukturen Von Chlorometallaten [M = V(III), Mo(V)]

2001 ◽  
Vol 56 (8) ◽  
pp. 759-764 ◽  
Author(s):  
Soheila Chitsaz ◽  
Effat Iravani ◽  
Jochen Pauls ◽  
Bernhard Neumüller
Keyword(s):  
Ir Spectroscopy ◽  
Membered Ring ◽  
Dinuclear Complex ◽  
Monoclinic Space Group ◽  
Asymmetric Unit ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Independent Molecules ◽  
Triclinic Form

[(THF)2LiCl2VCl2(THF)2] (1) and [Li(THF)4][OMoCl4(THF)] (2) can be prepared by the reactions of VCI3 with LiCl in THF and of Li(H)PtBu with OM0 CI4 in THF, respectively. 1 and 2 were characterized by IR spectroscopy, MS spectrometry (2) and X-ray crystallography. 1 can be obtained in two modifications depending on the temperature of crystallization. At -30 °C a triclinic form, 1a, was isolated from THF solution with one unique molecule per asymmetric unit. However, at 20 °C, 1b crystallized in the monoclinic space group P2/c. It possesses four independent molecules per asymmetric unit. According to the structure analyses 1 consists of a dinuclear complex with a planar LiCl2V four-membered ring while 2 consists of seperate ions [Li(THF)4]+ and [OMoCl4(THF)]-

Crystal Structures of (3S*,4S*,5S*,6S*)-3,4-Epoxy- 1,7-dioxaspiro[5.5]undecan-5-ol, (3R*,5S*,6S*)-1,7- Dioxaspiro[5.5]undecane-3,5-diyl Diacetate and (4S*,5S*,6S*)-1,7-Dioxaspiro[5.5]undecane-4,5-diol

1997 ◽  
Vol 50 (2) ◽  
pp. 123
Author(s):  
Margaret A. Brimble ◽  
Andrew Johnston ◽  
Trevor W. Hambley ◽  
Peter Turner
Keyword(s):  
Hydrogen Bonding ◽  
Hydroxy Group ◽  
Axial Position ◽  
Monoclinic Space Group ◽  
Equatorial Position ◽  
Intermolecular Hydrogen Bonding ◽  
Orthorhombic Space Group ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray Crystallography

The structures of (3S*,4S*,5S*,6S*)-3,4-epoxy-1,7-dioxaspiro[5.5]undecan-5-ol (2), (3R*,5S*,6S*)-1,7- dioxaspiro[5.5]undecane-3,5-diyl diacetate (4) and (4S*,5S*,6S*)-1,7-dioxaspiro[5.5]undecane-4,5-diol (5) have been determined by X-ray crystallography. The unsubstituted tetrahydropyran ring in (2) adopts an axial position with respect to the epoxy-substituted ring and the hydroxy group at C5 is syn to the epoxide group. Intermolecular hydrogen bonding is observed between the C5 hydroxy group and O1. The two six-membered rings in (4) adopt chair conformations and the two acetate groups adopt 1,3-diaxial positions. The C5 hydroxy group in (5) assumes an axial position anti to the C-O bond of the neighbouring ring whilst 4-OH occupies an equatorial position. Intermolecular hydrogen bonding is also observed between 4-OH and 5-OH. Compound (2), C9H14O4, M 186·21, crystallized in the monoclinic space group P 21/c with a 7·867(1), b 12·2060(9), c 9·3676(8) Å, b 102·744(8), V 877·4(1) Å 3 and No 1163 [I > 2·5s (I)], R 0·031, Rw 0·035. Compound (4), C13H20O6, M 272·30, crystallized in the triclinic space group P 1 with a 9·902(1), b 11·0024(9), c 6·9183(5)Å, a 104·078(8), b 96·769(9), g 101·980(8), V 703·8(1) Å 3 , No 1657 [I > 2·5s(I)], R 0·047, Rw 0·044. Compound (5), C9H16O4, M 188·22, crystallized in the orthorhombic space group Pbca with a 25·504(3), b 8·909(2), c 8·038(2) Å, V 1826·4(5) QA 3 , No 1096 [I > 2·5s(I)], R 0·030, Rw 0·030.

Self-assembling of three rare structurally various homomultinuclear CuII complexes derived from a bis(salamo)-based multioxime ligand

2021 ◽  
Vol 77 (5) ◽  
pp. 848-860
Author(s):  
Peng Li ◽  
Ting Zhang ◽  
Li-Li Li ◽  
Wen-Kui Dong
Keyword(s):  
Complex Structure ◽  
Three Dimensional ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray Crystallography ◽  
Self Assembling ◽  
Elemental Analyses ◽  
New Type ◽  
Spiral Structures ◽  
Solvent Molecules

A family of rare structurally different homometal multinuclear CuII bis(salamo)-based complexes, [Cu4(L)2(MeOH)2](ClO4)2·2MeOH (1), [Cu4(L)2(EtOH)2](NO3)2·2EtOH (2) and [Cu2(HL)(EtOH)Br2]·CHCl3 (3), has been successfully synthesized by the reactions of cupric salts with a bis(salamo)-based multidentate chelate ligand (H3 L). The salamo-based ligand [R-CH=N—O—(CH2) n —O—N=CH—R] is a new type of salen-based analog. Complexes (1) and (2) are isostructural structures, and crystallize in monoclinic space group P21/n with centrosymmetric spiral structures, where the main structures contain two fully deprotonated ligand (L)3− units, a charged tetranuclear CuII folding center and two coordinated solvent molecules. Complex (3) crystallizes in monoclinic space group Cc and consists of two CuII cations, one incompletely deprotonated ligand (HL)2− unit and one coordinated ethanol molecule, and forms a novel homo-binuclear CuII complex structure due to Br− counter anions. Complexes (1)–(3) have zero-dimensional cluster-based structures and are further assembled into three-dimensional frameworks via intermolecular interactions. Because of the different solvents and counter anions which have a significant influence on the structures of complexes (1)–(3), the interactions were quantitatively evaluated by Hirshfeld surfaces analyses. Complexes (1)–(3) have been characterized by elemental analyses, IR spectra, UV–vis spectra and X-ray crystallography analyses. In addition, fluorescence properties are evaluated and DFT calculations are performed.

Sign in / Sign up

Export Citation Format

Share Document