Preparation and Crystal Structures of Low-Valent Zirconocene Complexes Containing Tetramethyl(phenyl)cyclopentadienyl Ligands

2007 ◽  
Vol 72 (5-6) ◽  
pp. 679-696 ◽  
Author(s):  
Michal Horáček ◽  
Jiří Pinkas ◽  
Jiří Kubišta ◽  
Ivana Císařová ◽  
Róbert Gyepes ◽  
...  
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Spectroscopic Methods ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Cyclopentadienyl Ligands ◽  
Low Valent

Zirconocene complex [ZrCl2(η5-C5Me4Ph)2] (1) prepared by metathesis of the appropriate lithium cyclopentadienide and ZrCl4 was reduced with magnesium in tetrahydrofuran in the presence of excess bis(trimethylsilyl)acetylene, yielding the low-valent complex [Zr(η5-C5Me4Ph)2- (η2-Me3SiC≡CSiMe3)] (2). However, in addition to 2, the reduction afforded an unexpected Zr(II) complex [Zr(η5-C5Me4Ph)2(s-trans-η4-buta-1,3-diene)] (3). Compounds 1-3 were characterized by spectroscopic methods and by X-ray single-crystal diffraction.

scholarly journals Crystal structures of titanium–aluminium and –gallium complexes bearing twoμ2-CH3units

2017 ◽  
Vol 73 (5) ◽  
pp. 691-693 ◽  
Author(s):  
Tim Oswald ◽  
Mira Diekmann ◽  
Annika Frey ◽  
Marc Schmidtmann ◽  
Rüdiger Beckhaus
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Lewis Acids ◽  
Methyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Methyl Methyl ◽  
Low Valent ◽  
Titanium Aluminium ◽  
Gallium Complexes

The isotypic crystal structures of two titanocene complexes containing anEMe3unit (E =Al, Ga; Me = methyl) with twoμ2-coordinating methyl groups, namely [μ-1(η5)-(adamantan-1-yl-2κC1)cycylopentadienyl]di-μ2-methyl-methyl-2κC-[1(η5)-pentamethylcyclopentadienyl]aluminiumtitanium(III), [AlTi(CH3)3(C10H15)(C15H18)], and [μ-1(η5)-(adamantan-1-yl-2κC1)cycylopentadienyl]di-μ2-methyl-methyl-2κC-[1(η5)-pentamethylcyclopentadienyl]galliumtitanium(III), [GaTi(CH3)3(C10H15)(C15H18)], are reported. Reacting a dinuclear nitrogen-bridged low-valent titanium(III) complex with the Lewis acids AlMe3or GaMe3results in the loss of molecular dinitrogen and the formation of two monomeric titanocene(III) fragments bearing twoμ2-bridging methyl groups. Single crystal X-ray diffraction reveals the formation of a newE—C bond involving the pentafulvene ligand while the bridging and terminal methyl groups remain intact.

scholarly journals Structure of Biologically Active Benzoxazoles: Crystallography and DFT Studies

2021 ◽  
Vol 68 (1) ◽  
pp. 144-150
Author(s):  
Una Glamočlija ◽  
Selma Špirtović-Halilović ◽  
Mirsada Salihović ◽  
Iztok Turel ◽  
Jakob Kljun ◽  
...  
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Energy Gap ◽  
Molecular Geometry ◽  
Biologically Active ◽  
Basis Set ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Experimental Values ◽  
Homo Lumo

Using X-ray single crystal diffraction, the crystal structures of biologically active benzoxazole derivatives were determined. DFT calculation was performed with standard 6-31G*(d), 6-31G** and 6-31+G* basis set to analyze the molecular geometry and compare with experimentally obtained X-ray crystal data of compounds. The calculated HOMO-LUMO energy gap in compound 2 (2-(2-hydroxynaphtalen-1-yl)-4-methyl-7-isopropyl-1,3-benzoxazol-5-ol) is 3.80 eV and this small gap value indicates that compound 2 is chemically more reactive compared to compounds 1 (4-methyl-2-phenyl-7-isopropyl-1,3-benzoxazol-5-ol) and 3 (2-(4-chlorophenyl)-4-methyl-7-isopropyl- 1,3-benzoxazol-5-ol). The crystal structures are stabilized by both intra- and intermolecular hydrogen bonds in which an intermolecular O–H⋅⋅⋅N hydrogen bond generates N3 and O7 chain motif in compounds 1, 2, and 3, respectively. The calculated bond lengths and bond angles of all three compounds are remarkably close to the experimental values obtained by X-ray single crystal diffraction.

Formamidinium Salts of Low Valent Metal Halide Anions MX3 – (M = Ge, Sn) and M2X62– (M = Ga, In)

2004 ◽  
Vol 59 (11-12) ◽  
pp. 1524-1531 ◽  
Author(s):  
Xin Tian ◽  
Tania Pape ◽  
Norbert W. Mitzel
Keyword(s):  
Hydrogen Bonds ◽  
Single Crystal ◽  
Crystal Structures ◽  
Raman Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths ◽  
Metal Metal ◽  
Weak Hydrogen Bonds ◽  
Low Valent

Tetramethylformamidinium trichlorogermanite, [CH(NMe2)2][GeCl3], tetramethylformamidinium trichlorostannite, [CH(NMe2)2][SnCl3], bis-(tetramethylformamidinium hexaiododigallate, [CH(NMe2)2]2[Ga2I6] and bis-(tetramethylformamidinium hexachlorodiindate, [CH(NMe2)2]2[In2Cl6] have been prepared by the reactions between tetramethylformamidinium chloride, [CH(NMe2)2]Cl, and the corresponding low valent halides GeCl2 (as dioxane adduct), SnCl2, “GaI” and InCl. Their crystal structures have been determined by single crystal X-ray diffraction. [CH(NMe2)2][GeCl3] aggregates in a centrosymmetric dimeric structure, in which two trigonal pyramidal GeCl3 units are connected together by two weak Ge···Cl bonds and each Ge atom is bonded to one cation by a weak Ge···N contact. Two sets of weak hydrogen bonds C-H···Cl are observed with bond lengths of 2.87(2) Å and 2.85(2) Å . In [CH(NMe2)2][SnCl3], the SnCl3 − units adopts a (3+3) coordination with three normal Sn-Cl bonds and three weak Sn···Cl contacts. [CH(NMe2)2]2[Ga2I6] and [CH(NMe2)2]2[In2Cl6] contain metal-metal bonded anions with distorted staggered ethane-like conformations. The metal-metal bond lengths are 2.423(1) Å (Ga-Ga) and 2.719(1) Å (In-In). Their Raman spectra contain intense bands at 118.7 cm−1(Ga-Ga) and 174.7 cm−1(In-In) associated with metal-metal stretching modes.

Structure Types of Dihydroergotoxine Mesylates

2002 ◽  
Vol 67 (4) ◽  
pp. 490-501 ◽  
Author(s):  
Hana Petříčková ◽  
Jan Čejka ◽  
Michal Hušák ◽  
Bohumil Kratochvíl ◽  
Ivana Císařová ◽  
...  
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Ethanol Solvate

Three new crystal structures of dihydroergopeptines: dihydro-α-ergokryptine mesylate monohydrate acetone solvate (1), dihydro-α-ergokryptine mesylate monohydrate nitromethane solvate (2), and dihydroergocornine mesylate monohydrate methanol solvate (3) have been determined by X-ray single crystal diffraction. These structures were compared with published structures of dihydro-α-ergokryptine mesylate monohydrate ethanol solvate (4), dihydro-β-ergokryptine mesylate monohydrate methanol solvate (5), and dihydroergocristine mesylate monohydrate (6).

scholarly journals Syntheses, Reactivities, Characterization, and Crystal Structures of Dipalladium Complexes Containing the 1,3-pyrimidinyl Ligand: Structures of [Pd(PPh3)(Br)]2(μ,η2-C4H3N2)2, [Pd(Br)]2(μ,η2-Hdppa)2, and [{Pd(PPh3)(CH3CN)}2(μ,η2-C4H3N2)2][BF4]2

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2035
Author(s):  
Hsiao-Fen Wang ◽  
Kuang-Hway Yih ◽  
Gene-Hsiang Lee
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Room Temperature ◽  
Palladium Complex ◽  
Chloroform Solution ◽  
Bidentate Ligand ◽  
Tridentate Ligand ◽  
Spectroscopic Methods ◽  
X Ray Diffraction ◽  
X Ray

In a refluxing chloroform solution, the η1-pyrimidinyl {pyrimidinyl = C4H3N2} palladium complex [Pd(PPh3)2(η1-C4H3N2)(Br)], 1 exhibited intermolecular displacement of two triphenylphosphine ligands to form the doubly bridged η2-pyrimidinyl Dipalladium complex [Pd(PPh3)(Br)]2(μ,η2-C4H3N2)2, 3. The treatment of 1 with Hdppa {Hdppa = N,N-bisdiphenyl phosphinoamine} in refluxing dichloromethane yielded the doubly bridged Hdppa dipalladium complex [Pd(Br)]2(μ,η2-Hdppa)2, 4. Complex 1 reacted with the bidentate ligand, NH4S2CNC4H8 and, NaS2COEt, and the tridentate ligand, KTp {Tp = tris(pyrazoyl-1-yl)borate}, to form the η2-dithio η1-pyrimidinyl complex [Pd(PPh3)(η1-C4H3N2)(η2-SS)], (5: SS = S2CNC4H8; 6: SS = S2COEt) and η2-Tp η1-pyrimidinyl complex [Pd(PPh3)(η1-C4H3N2)(η2-Tp)], 7, respectively. Treatment of 1 with AgBF4 in acetonitrile at room temperature resulted in the formation of the doubly bridged η2-pyrimidinyl dipalladium complex [{Pd(PPh3)(CH3CN)}2(μ,η2-C4H3N2)2][BF4]2, 8. All of the complexes were identified using spectroscopic methods, and complexes 3, 4, and 8 were determined using single-crystal X-ray diffraction analyses.

Structure characterization with neutron powder data of LaGaO3 and NdGaO3 based on X-ray single-crystal data: evidence for an inversion center

1996 ◽  
Vol 211 (12) ◽  
Author(s):  
W. Marti ◽  
P. Fischer ◽  
J. Schefer ◽  
F. Kubel
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
Structure Characterization ◽  
Inversion Center ◽  
Crystal Data ◽  
Single Crystal Diffraction ◽  
X Ray

AbstractFrom neutron powder diffraction intensities it is often problematic to distinguish between centrosymmetry and non-centrosymmetry. X-ray single crystal diffraction may be more accurate. In this paper we compare refinement results of crystal structures on the basis of neutron powder data of orthorhombic NdGaO

Hydrogen bonding in hydroxypyridium salts

2018 ◽  
Vol 233 (7) ◽  
pp. 501-506
Author(s):  
Andrei V. Mironov ◽  
Victor A. Tafeenko ◽  
Dmitrii Yu. Grebenkin ◽  
Alexander E. Oblezov
Keyword(s):  
Hydrogen Bonding ◽  
Oxygen Atom ◽  
Single Crystal ◽  
Crystal Structures ◽  
Diffraction Data ◽  
Nitrate Anion ◽  
Single Crystal Diffraction ◽  
Space Group ◽  
X Ray ◽  
Unit Cells

Abstract The crystal structures of 6-methyl-2-ethyl-3-hydroxypyridiniun nitrate (C8H12NO)NO3 (I) and fumarate (C8H12NO)2C4H2O4 (II) were solved and refined from X-ray single crystal diffraction data (CuKα, (I) a=4.6477(2), b=14.5906(9), c=14.5551(8) Å, β=99.100(4)°, space group P21/c, Z=4, Rp/Rwp=0.033/0.047; (II) a=8.8293(3), b=13.4268(5), c=8.3893(3) Å, β=96.303(3)°, space group P21/c, Z=2, Rp/Rwp= 0.034/0.049). Both structures are built of infinite chains along ac diagonal of the unit cells formed by hydrogen bonding between the hydroxypyridium cation and the corresponding anion. Each fumarate anion is linked to four hydroxypyridium cations while nitrate anion is connected with two hydroxypyridium cations only leaving one oxygen atom in the nitrogen group isolated.

scholarly journals Environmentally Friendly Nafion-Catalyzed Synthesis of Substituted 2-Ethyl-3-Methylquinolines from Aniline and Propionaldehyde under Microwave Irradiation

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 877
Author(s):  
Chieh-Kai Chan ◽  
Chien-Yu Lai ◽  
Cheng-Chung Wang
Keyword(s):  
Reaction Mechanism ◽  
Microwave Irradiation ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Environmentally Friendly ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Related Data ◽  
Heating Source ◽  
Chemical Structures

Herein, we report a facile synthetic methodology for the preparation of 2,3-dialkylquinolines from anilines and propionaldehydes. This cyclization involved environmentally friendly Nafion® NR50 as an acidic catalyst with microwave irradiation as the heating source. A series of substituted 2-ethyl-3-methylquinolines were prepared from various anilines and propionaldehyde derivatives through this protocol with good to excellent yields. Some new chemical structures were confirmed by X-ray single-crystal diffraction analysis and the related data were provided. The plausible reaction mechanism studies are also discussed.

scholarly journals Structures, Chemical Conversions, and Cytotoxicity of Tricholopardins C and D, Two Tricholoma Triterpenoids from the Wild Mushroom Tricholoma pardinum

2021 ◽  
Author(s):  
Chen Shi ◽  
Yue-Ling Peng ◽  
Juan He ◽  
Zheng-Hui Li ◽  
Ji-Kai Liu ◽  
...  
Keyword(s):  
Hela Cell ◽  
Single Crystal ◽  
Cell Lines ◽  
Cell Apoptosis ◽  
Spectroscopic Methods ◽  
Wild Mushroom ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hela Cell Lines ◽  
Mcf 7

AbstractTwo undescribed Tricholoma triterpenoids, namely tricholopardins C (1) and D (2), were isolated from the wild mushroom Tricholoma pardinum. Their structures with absolute configurations were elucidated by spectroscopic methods, as well as the single crystal X-ray diffraction. Compounds 1 and 2 were further obtained by chemical conversions from the known analogues. Compound 1 showed significant cytotoxicity to MCF-7 and Hela cell lines with IC50 values of 4.7 μM and 9.7 μM, respectively. Its mechanism of inducing MCF-7 cell apoptosis was studied briefly. Graphical Abstract

Crystal structures of (S)- and (R,S)-2,2′-bipyridine-3,3′-dicarboxylic acid 1,1′-dioxides and of their barium salts: absolute configuration and molecular distortion enforced by supramolecular self-assembly

1997 ◽  
Vol 212 (3) ◽  
Author(s):  
P. Vojtíšek ◽  
I. Císařová ◽  
J. Podlaha ◽  
Z. Žák ◽  
S. Böhm ◽  
...  
Keyword(s):  
Single Crystal ◽  
Dicarboxylic Acid ◽  
Crystal Structures ◽  
Absolute Configuration ◽  
Self Assembly ◽  
Barium Salt ◽  
X Ray Diffraction ◽  
X Ray

AbstractCrystal structures of the title compounds were determined by single crystal X-ray diffraction. Absolute configuration of the barium salt of (+)-(

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