Reactivity of [M4(co)12(µ-pyms)4] (M = Mn, re; pymS = pyrimidine-2-Thiolate) with bis(triphenylphosphino)nickel(ii) dicarbonyl: X-ray crystal structure of [Re(Co)3(?2-pymS)(PPh3)]

The reaction between the tetranuclear compound [Mn4(CO)12(µ -pymS)4] (1) and (PPh3)2Ni(CO)2 at room temperature resulted in the cleavage of the square to afford the dinuclear complex [Mn2(CO)5(µ -pymS)2(PPh3)] (2) (19%) along with two mononuclear complexes fac- [Mn(CO)3(?2-pymS)(PPh3)] (3) (43%) and [Mn(CO)2(?2-pymS)(PPh3)2] (4) (24%). In contrast, a similar reaction of [Re4(CO)12(µ-pymS)4] (5) with (PPh3)2Ni(CO)2 at 25oC did not afford any dinuclear compound leading instead to the monophosphine substituted mononuclear compound fac- [Re(CO)3(?2-pymS)(PPh3)] (6) (72%). Compound 4 is also formed when a toluene solution of 3 is treated with PPh3 at elevated temperature (100oC). A similar treatment of 6 with triphenylphosphine in refluxing toluene gave [Re(CO)2(?2-pymS)(PPh3)2] (7) (60%). All the new compounds have been characterized by elemental analysis, IR, 1H NMR and 31P{1H} NMR spectroscopy and mass spectrometry along with single crystal X-ray diffraction analysis for 6. Compound 6 consists of a single rhenium atom with three carbonyls, a triphenylphosphine ligand and a chelating pyrimidinethiolate ligand. DOI: http://dx.doi.org/10.3329/jbas.v38i2.21340 Journal of Bangladesh Academy of Sciences, Vol. 38, No. 2, 155-165, 2014

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The Electron Effect of Aromatic Group: Control Conformation of 2-Aromatic Cyclododecanone Derivatives

Current Organic Chemistry ◽

10.2174/1385272824999200607175514 ◽

2020 ◽

Vol 24 (10) ◽

pp. 1139-1147

Author(s):

Yang Mingyan ◽

Wang Daoquan ◽

Wang Mingan

Keyword(s):

1H Nmr ◽

13C Nmr ◽

Nmr Spectra ◽

Coupling Constants ◽

The Other ◽

Repulsive Interaction ◽

X Ray Diffraction ◽

X Ray ◽

Electron Effect ◽

Group Control

2-Phenylcyclododecanone and 2-cyclohexylcyclododecanone derivatives were synthesized and characterized by 1H NMR, 13C NMR, HR-ESI-MS and X-ray diffraction. Their preferred conformations were analyzed by the coupling constants in the 1H NMR spectra and X-ray diffraction, which showed the skeleton ring of these derivatives containing [3333]-2-one conformation, and the phenyl groups were located at the side-exo position of [3333]-2-one conformation due to the strong π-π repulsive interaction between the π- electron of benzene ring and π-electron of carbonyl group. The cyclohexyl groups were located at the corner-syn or the side-exo position of [3333]-2-one conformation depending on the hindrance of the other substituted groups. The π-π electron effect played a crucial role in efficiently controlling the preferred conformation of 2-aromatic cyclododecanone and the other 2-aromatic macrocyclic derivatives with the similar preferred square and rectangular conformations.

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Two types of Ln2Cu2 hydroxo-trimethylacetate complexes with 0D and 1D motifs: synthetic features, structural differences, and slow magnetic relaxation

Dalton Transactions ◽

10.1039/d1dt01161h ◽

2021 ◽

Author(s):

Anna Bovkunova ◽

Evgeniya S. Bazhina ◽

Igor Evstifeev ◽

Yulia V. Nelyubina ◽

Maxim Shmelev ◽

...

Keyword(s):

Magnetic Relaxation ◽

X Ray Diffraction ◽

Metal Core ◽

X Ray ◽

Trimethylacetate Complexes ◽

Structural Differences ◽

Slow Magnetic Relaxation ◽

New Compounds

Two series of heterometallic LnIII−CuII compounds containing a butterfly-like tetranuclear metal core were synthesized and characterized by X-ray diffraction and magnetometry. The structures of the new compounds were shown to...

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Synthese und Kristallstrukturen einiger Tetramethylstibonium-Hydrogendicarboxylate / Synthesis and Crystal Structures of Some Tetramethylstibonium Hydrogendicarboxylates

Zeitschrift für Naturforschung B ◽

10.1515/znb-1982-1106 ◽

1982 ◽

Vol 37 (11) ◽

pp. 1393-1401 ◽

Cited By ~ 12

Author(s):

Beatrix Milewski-Mahrla ◽

Hubert Schmidbaur

Keyword(s):

Hydrogen Bonds ◽

Crystal Structures ◽

Spectroscopic Data ◽

Molar Ratio ◽

Ionic Structure ◽

X Ray Diffraction ◽

X Ray ◽

Carboxylate Oxygen ◽

Donor Acceptor ◽

New Compounds

Reactions of pentamethylantimony (CH3)5Sb with carboxylic acids in the molar ratio 1:2 afford one equivalent of methane and essentially quantitative yields of crystalline tetramothylstibonium hydrogendicarboxylates. Six new compounds of this series have been synthesized using benzoic, o-phthalic, salicylic, 4-ethoxy-salicylic, oxalic, and malic acid, and characterized by analytical and spectroscopic data. An ionic structure with strong hydrogen bonds in the anionic components is proposed.The crystal structures of the hydrogen-dibenzoato (1), hydrogen-ortho-plithalato (2) and 4-ethoxy-hydrogen-salicylate (3) were determined by single crystal X-ray diffraction. The compounds can be described as having ionic lattices with some donor-acceptor interactions between the stibonium centers and the carboxylate oxygen atoms. The anions are characterized by strong hydrogen bonds O...H...O. Thus, the (CH3)4Sb-tetrahedron in 1 is distorted by two benzoate oxygon atoms (at 304(2) and 340(2) pin). The cation in 2 is largely undistorted and the anion has a hydrogenphthalate hydrogen bond of d(O...H...O) = 232 pm. The cation-anion contact in 3 is as short as d(Sb-O) = 289 pm rendering the Sb atom pentacoordinate.

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Influence of the Para-Substituent in Lanthanoid Complexes of Bistetrazole Substituted Calix[4]arenes

10.26434/chemrxiv.9255209 ◽

2019 ◽

Author(s):

Rene Z.H. Phe ◽

Brian Skelton ◽

Massimiliano Massi ◽

Mark Ogden

Keyword(s):

Structural Changes ◽

Cluster Formation ◽

Ammonium Cation ◽

Ammonium Salts ◽

X Ray Diffraction ◽

One Dimensional ◽

X Ray ◽

Mononuclear Complexes ◽

Scattering Measurements ◽

The Impact

5,11,17,23-Tetra-tert-butyl-25,27-dihydroxy-26,28-bis(tetrazole-5-ylmethoxy)calix[4]arene has been reported to form remarkable Ln19 and Ln12 elongated clusters, upon addition of aqueous ammonium carboxylates. The impact of the para substituent on lanthanoid cluster formation has been studied by synthesising two new bis-tetrazole calixarenes, with p-H, and p-allyl substituents. Solution phase dynamic light scattering measurements of the reaction mixtures indicated that clusters are not formed with the p-H and p-allyl derivatives, in contrast with the behaviour of the t-butyl analogue. Lanthanoid complexes of the p-H and p-allyl calixarenes were characterised by single crystal X-ray diffraction, and were found to form mononuclear complexes, linked to form a one-dimensional coordination polymer for the p-allyl system. All of the complexes were isolated as ammonium salts, with ammonium cation included in the calixarene cavity in most cases. It is concluded that the nature of the para substituent has a profound impact on the lanthanoid cluster formation process, and derivatives with more subtle structural changes will be required to determine if additional lanthanoid “bottlebrush” clusters can be isolated.

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Thiocarbonyl Complexes of Rhenium. Part I.

Zeitschrift für Naturforschung B ◽

10.1515/znb-1993-0611 ◽

1993 ◽

Vol 48 (6) ◽

pp. 771-777 ◽

Cited By ~ 6

Author(s):

Ulrich Abram ◽

Bernd Lorenz

Keyword(s):

Mass Spectrometry ◽

Nmr Spectroscopy ◽

Coordination Geometry ◽

X Ray Diffraction ◽

Rhenium Atom ◽

Space Group ◽

X Ray ◽

Monomeric Complex ◽

Structure Solution ◽

R Value

Novel rhenium complexes with terminal thiocarbonyl groups have been synthesized from ReCl3(Me2PhP)3 and sodium diethyldithiocarbamate. mer-(Diethyldithiocarbamato)tris-(dimethylphenylphosphine)(thiocarbonyl)rhenium(I), mer-[Re(CS)(Me2PhP)3(Et2dtc)], and tris(diethyldithiocarbamato)(thiocarbonyl)rhenium(III), [Re(CS)(Et2dtc)3] have been studied by infrared and NMR spectroscopy, mass spectrometry and X-ray diffraction.mer-[Re(CS)(Me2PhP)3(Et2dtc)] crystallizes orthorhombic in the space group Pna21 with a = 1516.1(2), b = 2189.8(2) and c = 1035.6(1) pm. Structure solution and refinement converged at R = 0.042. The coordination geometry is a distorted octahedron. The Re—C bond length is found to be 184(2) pm.[Re(CS)(Et2dtc)3] crystallizes monoclinic in the space group P21/c with a = 962.2(6), b = 1744.0(2), c = 1537.4(6) pm and β = 96.21(1)°. The final R value is 0.028. In the monomeric complex the rhenium atom is seven-coordinate with an approximate pentagonal-bipyramidal coordination sphere and a rhenium-carbon distance of 181(1) pm.

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Studies of the rhenium-oxygen bond. III. The crystal and molecular structure of 1-oxo-6-ethoxo-2,4-dichloro-3,5-dipyridinerhenium(V)

Canadian Journal of Chemistry ◽

10.1139/v77-049 ◽

1977 ◽

Vol 55 (2) ◽

pp. 333-339 ◽

Cited By ~ 30

Author(s):

Colin James Lyne Lock ◽

Graham Turner

Keyword(s):

Molecular Structure ◽

Single Crystal ◽

Title Compound ◽

Crystal And Molecular Structure ◽

Dominant Factor ◽

X Ray Diffraction ◽

Rhenium Atom ◽

Full Matrix ◽

X Ray ◽

Oxygen Bond

The crystal and molecular structure of the title compound has been examined by single crystal X-ray diffraction. The crystals are monoclinic with a = 28.045(10), b = 8.766(3), c = 12.376(5) Å, β = 91.14(3)°. The space group is C2/c and there are eight molecules per unit cell. A total of 5053 independent reflections, of which 2860 were observed, were examined on a Syntex [Formula: see text] diffractometer. The structure was refined by full matrix least squares to an R2 value of 0.0449. The ligands form a very rough octahedron around the rhenium atom with Re—Cl(1), 2.441(3); Re—Cl(2), 2.366(3), Re—O(1), 1.684(7); Re—O(2), 1.896(6); Re—N(1), 2.144(7); Re—N(2), 2.132(7) Å. The pyridine rings are a dominant factor in determining the details of the molecular structure.

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Synthesis of ReItricarbonyl complexes with various sulfur- and oxygen-donating ligands: crystal structures of two ReIdinuclear structures bridged by S atoms

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s205322961801207x ◽

2018 ◽

Vol 74 (10) ◽

pp. 1116-1122

Author(s):

Pheello I. Nkoe ◽

Hendrik G. Visser ◽

Chantel Swart ◽

Alice Brink ◽

Marietjie Schutte-Smith

Keyword(s):

Hydrogen Bond ◽

Intermolecular Hydrogen Bond ◽

Synthesis And Characterization ◽

X Ray Diffraction ◽

Metal Centre ◽

Pyridine Ligand ◽

X Ray ◽

Hydrogen Bond Interactions ◽

Mononuclear Complexes

The synthesis and characterization of two dinuclear complexes, namelyfac-hexacarbonyl-1κ3C,2κ3C-(pyridine-1κN)[μ-2,2′-sulfanediyldi(ethanethiolato)-1κ2S1,S3:2κ3S1,S2,S3]dirhenium(I), [Re2(C4H8S3)(C5H5N)(CO)6], (1), and tetraethylammoniumfac-tris(μ-2-methoxybenzenethiolato-κ2S:S)bis[tricarbonylrhenium(I)], (C8H20N)[Re2(C7H7OS)3(CO)6], (2), together with two mononuclear complexes, namely (2,2′-bithiophene-5-carboxylic acid-κ2S,S′)bromidotricarbonylrhenium(I), (3), and bromidotricarbonyl(methyl benzo[b]thiophene-2-carboxylate-κ2O,S)rhenium(I), (4), are reported. Crystals of (1) and (2) were characterized by X-ray diffraction. The crystal structure of (1) revealed two Re—S—Re bridges. The thioether S atom only bonds to one of the ReImetal centres, while the geometry of the second ReImetal centre is completed by a pyridine ligand. The structure of (2) is characterized by three S-atom bridges and an Re...Re nonbonding distance of 3.4879 (5) Å, which is shorter than the distance found for (1) [3.7996 (6)/3.7963 (6) Å], but still clearly a nonbonding distance. Complex (1) is stabilized by six intermolecular hydrogen-bond interactions and an O...O interaction, while (2) is stabilized by two intermolecular hydrogen-bond interactions and two O...π interactions.

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Four New Cytotoxic Arborinane-Type Triterpenes from the Endolichenic Fungus Myrothecium inundatum

Planta Medica ◽

10.1055/a-0855-4051 ◽

2019 ◽

Vol 85 (09/10) ◽

pp. 701-707 ◽

Cited By ~ 3

Author(s):

Buddha Bahadur Basnet ◽

Li Liu ◽

Baosong Chen ◽

Yerlan Melsuly Suleimen ◽

Haiyang Yu ◽

...

Keyword(s):

Absolute Configuration ◽

Ethyl Acetate Extract ◽

Human Cancer ◽

Diffraction Experiment ◽

Human Cancer Cell ◽

X Ray Diffraction ◽

X Ray ◽

Human Cancer Cell Lines ◽

Endolichenic Fungus ◽

New Compounds

AbstractTwo new arborinane-type triterpenes, myrotheols A (1) and B (2), two new arborinane-type glycosides, myrothesides C (3) and D (4), together with four known diterpenes (5 – 8) were isolated from the ethyl acetate extract of the endolichenic fungus Myrothecium inundatum. The structures of new compounds 1 – 4 were elucidated by NMR and MS analyses. The absolute configuration of 1 was assigned by a single-crystal X-ray diffraction experiment. Compounds 3 and 4 represent the first two natural 4-O-methyl-α-D-mannosides. Compounds 1 – 8 exhibited cytotoxicity against K562 and RKO human cancer cell lines.

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