Organometallic oxides: preparation of the cluster [(η-C5Me5)Mo]4O7 by reduction of [(η-C5Me5)MoCl(O)]2(μ-O) or (η-C5Me5)MoCl2(O)

2000 ◽  
Vol 78 (3) ◽  
pp. 383-394
Author(s):  
Frank Bottomley ◽  
Victor Sanchez ◽  
Robert C Thompson ◽  
Olusola O Womiloju ◽  
Zhiqiang Xu
Keyword(s):  
Nmr Spectra ◽  
Chloroform Solution ◽  
X Ray Diffraction ◽  
Broad Resonance ◽  
Nmr Spectrum ◽  
X Ray ◽  
Temperature Range ◽  
H Nmr ◽  
Tributyltin Hydride ◽  
Effective Moment

Reduction of [(η-C5Me5)MoCl(O)]2(μ-O) or (η-C5Me5)MoCl2(O) with sodium or magnesium amalgam, magnesium turnings, or tributyltin hydride produced [(η-C5Me5)Mo]4O7, with [(η-C5Me5)Mo(O)(μ-O)]2 as a co-product. [(η-C5Me5)Mo]4O7 was characterized by X-ray diffraction, mass spectrometry, 1H NMR and IR spectroscopies, and magnetism. Crystals of [(η-C5Me5)Mo]4O7 contained a tetrahedral [(η-C5Me5)Mo]4 unit (Mo-Mo = 2.909 (3) Å) with the Mo4O7 core having the structure Mo4(μ2-O(b))3(µ2-O(c))3(µ3-O(a)) (3). Microcrystalline samples of [(η-C5Me5)Mo]4O7 were paramagnetic over the temperature range 2-300 K, with an effective moment of 1.26 μB at 300 K. [(η-C5Me5)Mo]4O7 was also paramagnetic in chloroform solution, over the temperature range 223-298 K, with an effective moment of 1.43 µB at 298 K. The 1H NMR spectrum showed a broad resonance at 16.3 ppm (Δν 1/2 = 113 Hz) and two narrow resonances at 1.89 ppm and 1.69 ppm (Δν 1/2 = 5 Hz). The magnetism and NMR spectra showed that [(η-C5Me5)Mo]4O7 existed in two forms which were in equilibrium in solution. One form was paramagnetic (S = 1), with the Mo4O7 core having the geometry 3, and the other was diamagnetic (S = 0), with the Mo4O7 core having the geometry 4.Key words: cluster, cyclopentadienyl, molybdenum, oxide, paramagnetism.

tert-Butylimino-cyclopentadienyIvanadiuni(V)-Verbindungen Darstellung, Struktur und NMR-spektroskopische Untersuchungen

1987 ◽  
Vol 42 (7) ◽  
pp. 881-888 ◽  
Author(s):  
Fritz Preuss ◽  
Harald Becker ◽  
Hans-Joachim Häusler
Keyword(s):  
Molecular Structure ◽  
Diffraction Analysis ◽  
Temperature Dependence ◽  
Metal Atom ◽  
Nmr Spectra ◽  
X Ray Diffraction ◽  
Nmr Spectrum ◽  
X Ray ◽  
H Nmr ◽  
Intramolecular Rearrangements

Abstract The cyclopentadienyl compounds tC4R9N = VCpCl2 (2). tC4H9N = VCp(OtC4H9)Cl, tC4H9N = VCp(OtC4H9)(R) (R = CH3, "C4H9, CH2SiMe3), tC4H9N = VCp2(OtC4H9) (5) and ,tC4H9N = VCp(OtC4H9)2 have been prepared starting from tC4H9N = VCl31H and 51V NMR spectra are discussed; except for 5, the C5H5 rings are η5-coordinated to the metal atom. The temperature dependence of the 1H NMR spectrum of 5 indicates two types o f intramolecular rearrangements: η1/η5-Interchange of the C5H5 rings and fluxional behavior of the η1-C5H5 ring. The molecular structure of 2 has been investigated by X-ray diffraction analysis.

Preparation, properties and structure of some intermediate nido- and arachno-monocarbaboranes

1981 ◽  
Vol 46 (10) ◽  
pp. 2345-2353 ◽  
Author(s):  
Karel Baše ◽  
Bohumil Štíbr ◽  
Jiří Dolanský ◽  
Josef Duben
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Nmr Spectra ◽  
Liquid Ammonia ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Starting Compound

The 6-N(CH3)3-6-CB9H11 carbaborane reacts with sodium in liquid ammonia with the formation of 6-CB9H12- which was used as a starting compound for preparing the 4-CB8H14, 9-L-6-CB9H13 (L = (CH3)2S, CH3CN and P(C6H5)3), 1-(η5-C5H5)-1,2-FeCB9H10-, and 2,3-(η5-C5H5)2-2,31-Co2CB9H10- carboranes. The 4-CB8H14 compound was dehydrogenated at 623 K to give 4-(7)-CB8H12 carborane. Base degradation of 6-N(CH3)3-6-CB9H11 in methanol resulted in the formation of 3,4-μ-N(CH3)3CH-B5H10. The structure of all compounds was proposed on the basis of their 11B and 1H NMR spectra and X-ray diffraction was used in the case of the transition metal complexes.

Photoreaktionen von Dekacarbonyldirhenium mit Allen und unverzweigten Allenderivaten / Photoreactions of Decacarbonyldirhenium with Allene and Unbranched Derivatives of Allene

1995 ◽  
Vol 50 (4) ◽  
pp. 649-660 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Wolfgang Michels ◽  
Gerhard Heeb
Keyword(s):  
Nmr Spectra ◽  
Crystal And Molecular Structure ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Oxidative Rearrangement ◽  
Dirhenium Complexes ◽  
Derivatives Of ◽  
By Products

Decacarbonyldirhenium (1) reacts upon UV irradiation with allene (2), 1,2-butadiene (3) and 2,3-pentadiene (4) preferentially by CO substitution and oxidative rearrangement to the corresponding enneacarbonyl-μ-η1:3-endiyl-dirhenium complexes 5, 9, and 15 and to the octacarbonyl-μ-η2:2-allene-dirhenium complexes 6, the stereoisomers 10, 11, and 16. At elevated temperature 5, 9, and 15 loose CO and yield by a reductive rearrangement also the complexes 6, 10, 11, and 16. In addition to these main products, depending upon the allene derivative used, various by-products are obtained.By-products of the reaction o f 1 with 2 are octacarbonyl-μ-η3:3-(2,3-dimethylene-buta-1,4- diyl)dirhenium (7) and μ-η2:2-allene-hexacarbonyl-μ-η1:3-1-propene-1,3-diyl-dirheniurn (8). The photo reaction of 1 with 3 yields, in addition to 9-11, tetracarbonyl-η3-(E-5-ethylidene- 4-methyl-2-cyclopenten-1-yl)rhenium (12) and tetracarbonyl-η3-(Z-5-ethyliden-4- methyl-2-cyclopenten-1-yl)rhenium (13) as a mixture of isomers. 1 and 4 form the by-products tetracarbonyl-η3-(EZ-3-penten-2-yl)rhenium (17), tetracarbonyl-η3-(EE-3-penten-2-yl)rhenium (18) and heptacarbonyl-μ-η1:2:1:2-(4,5-dimethyl-2,6-octadiene-3,6-diyl)dirhenium (19) with an unusually bridging and chelating ligand. The constitutions of the reaction products have been concluded from the IR and 1H NMR spectra. For 19 the crystal and molecular structure has been determined by X-ray diffraction analysis.

Das 7,8-Benzo-5-chloro-1,4,4-trimethyl-1-aza-4-azonia-6,9-dioxa-5 λ5-phosphaspiro[4.4]nonanyl-Kation: Röntgenstrukturanalyse und temperaturabhängige 1H-NMR-Spektren: The 7, 8-Benzo-5-chloro-1,4,4-trimethyl-1-aza-4-azonia-6,9-dioxa-5 λ).5-phosphaspiro[4.4]nonanyl Cation: X-Ray Crystal Structure Determination and Variable 1H NMR Spectra

1992 ◽  
Vol 47 (6) ◽  
pp. 755-759 ◽  
Author(s):  
Thomas Kaukorat ◽  
Peter G. Jones ◽  
Reinhard Schmutzler
Keyword(s):  
Crystal Structure ◽  
1H Nmr ◽  
Nmr Spectra ◽  
Crystal Structure Analysis ◽  
Acceptor Interaction ◽  
Nmr Spectrum ◽  
X Ray ◽  
H Nmr ◽  
Trigonal Bipyramidal ◽  
Donor Acceptor

The 1H NMR spectrum of the spirophosphorane 3 at room temperature indicates dynamic behaviour of the cation. The low-temperature 1H NMR spectra of 3 exhibit two sets of doublets for the protons of the diastereotopic N(CH3)2 groups. The free enthalpy of activation for the dynamic process was determined (58.6 KJ/mole). In the reaction of 3 with sodium tetraphenylborate the crystalline compound, 4, involving the non-coordinating anion, [B(C6H5)4]-, was obtained. The X-ray crystal structure analysis of 4 reveals the presence of a five-membered ring, formally as a result of intramolecular donor-acceptor interaction between the nitrogen atom of the N(CH3)2 group and phosphorus. The geometry at phosphorus deviates somewhat from ideal trigonal bipyramidal.

Darstellung, 11B-und 19F-NMR-Spektren des Monofluoropentaiodo- closo-hexaboratanions sowie Kristallstruktur von (CH2Py2)[B6FI5]/ Synthesis, 11B and 19F NMR Spectra of the Monofluoropentaiodo-closo-hexaborate Anion and the Crystal Structure of (CH2Py2)[B6FI5]

1998 ◽  
Vol 53 (8) ◽  
pp. 829-832 ◽  
Author(s):  
H. Thomsen ◽  
W. Preetz
Keyword(s):  
Crystal Structure ◽  
Nmr Spectra ◽  
19F Nmr ◽  
Coupling Constant ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
19F Nmr Spectra ◽  
Nmr Spectrum ◽  
X Ray ◽  
Excess Iodine

Abstract By reaction of closo-[B6H5F]2- in alkaline solution with excess iodine the monofluoropentaiodo- closo-hexaborate anion [B6FI5]2- is formed in good yield. The crystal structure of (CH2Py2)[B6FI5] has been determined by single crystal X-ray diffraction analysis (orthorhombic, space group Pnma, a = 13.803(2), b = 11.759(2), c = 13.936(2) Å, Z = 4). The B-F-bond length is 1.41 Å, the B-I distances range from 2.13 to 2.17 Å, the B-B distances from 1.69 to 1.76 A. According to the C4v point symmetry the 11B NMR spectrum of the anion exhibits three singlets at +3.8,-30.1 and-33.3 ppm with the intensity ratio 1:4:1, the 19F NMR spectrum one quartet at -247.6 ppm with the coupling constant 1J (19F, 11B) = 54 Hz.

Preparation and Crystal Structure of Genistein Benzenesulfonate Prodrugs

2008 ◽  
Vol 2008 (10) ◽  
pp. 555-558 ◽  
Author(s):  
You Peng ◽  
Zeyuan Deng ◽  
Shaojie Lang ◽  
Yawei Fan
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Sulfonic Acid ◽  
Nmr Spectra ◽  
High Yield ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
H Nmr ◽  
Ester Prodrugs

In order to improve bioavailability and anticancer activity of genistein, a series of novel sulfonic acid ester prodrugs of the isoflavone genistein were synthesised in high yield with excellent regioselectivity. Their structures were characterised by IR, MS, elemental analysis and 1H NMR spectra. The crystal structure was examined by X-ray diffraction. X-ray structure determination revealed that all the aromatic rings in the compound are not coplanar. In the crystal structure, molecules are linked through intermolecular C-H···O hydrogen bonds, forming layers parallel to the ab plane.

A bis-Au(III) [28]hexaphyrin triphenylphosphine adduct

2016 ◽  
Vol 20 (08n11) ◽  
pp. 997-1001 ◽  
Author(s):  
Koji Naoda ◽  
Atsuhiro Osuka
Keyword(s):  
Solid State ◽  
Structural Analysis ◽  
Trifluoroacetic Acid ◽  
X Ray Diffraction ◽  
Nmr Spectrum ◽  
X Ray ◽  
H Nmr ◽  
Detailed Structural Analysis ◽  
Nir Absorption ◽  
Plausible Mechanism

Triphenylphosphine was added regioselectively at the C(3) position of bis-Au(III) complex of [26]hexaphyrin 5 in the presence of trifluoroacetic acid to produce [28]hexaphyrin triphenylphosphine adduct 6 in 62% yield, which has been fully characterized by NMR, UV-vis/NIR absorption, and MS spectroscopies, and X-ray diffraction analysis. The rigid planar structure forces 6 to take Hückel antiaromaticity, which has been supported by its 1H NMR spectrum. Curiously, the detailed structural analysis elucidated that the triphenylphosphine moiety exists as a phosphorane form in the solid state. A plausible mechanism via a double protonated 5 is proposed, which can explain the observed regioselectivity.

Structure of a pentacyclic triterpenyl angelate from Loeseliamexicana. 1H 2D-NMR data and stereochemistry

1989 ◽  
Vol 67 (12) ◽  
pp. 2071-2077 ◽  
Author(s):  
M. Jiménez E. ◽  
K. Velézquez ◽  
A. Lira-Rocha ◽  
A. Ortega ◽  
E. Díaz ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Parent Compound ◽  
2D Nmr ◽  
X Ray Diffraction ◽  
Pentacyclic Triterpene ◽  
Nmr Structure Determination ◽  
X Ray ◽  
H Nmr ◽  
Nmr Data ◽  
Unambiguous Assignment

The total assignment of 1H NMR spectra of a pentacyclic triterpene from Loeseliamexicana was performed using selected 2D-NMR experiments (COSY, NOE). X-ray diffraction data were obtained from the parent compound as supplemental information to the NMR investigations. The data allowed for the unambiguous assignment of the structure and the stereochemistry of the title compound. Keywords: pentacyclic triterpene NMR, 2D NMR of terpenes, X-ray of triterpenes, triterpenyl angelate NMR, X-ray -2D NMR structure determination.

Darstellung, 11B-NMR- und Schwingungsspektren von Aminohexahydro-closo-hexaborat(1–), [B6H6(NH2)]- sowie Kristallstruktur von Cs[B6H6(NH2)] · H2O / Preparation, 11B NMR and Vibrational Spectra of Aminohexahydro-closo-hexaborate(1–), [B6H6(NH2)]-, and the Crystal Structure of Cs[B6H6(NH2)] · H2O

1995 ◽  
Vol 50 (1) ◽  
pp. 11-14 ◽  
Author(s):  
A. Franken ◽  
W. Preetz
Keyword(s):  
Crystal Structure ◽  
Vibrational Spectra ◽  
Nmr Spectra ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Aqueous Alkaline Solution ◽  
Nmr Spectrum ◽  
X Ray ◽  
11B Nmr ◽  
Ir And Raman

Aminohexahydro-closo-hexaborate(1–), Crystal Structure, 11B NMR Spectra, Vibrational SpectraBy reduction of [B6H5(NO2)]2- with Fe2+ in aqueous alkaline solution [B6H6(NH2)]- is formed. The compound has been separated by extraction with dichloromethane in the presence of tetrabutylammoniumbromid and precipitated from the organic phase by adding CsCH3COO/C2H5OH. The Crystal structure of Cs[B6H6(NH2)] · H2O has been determined by single crystal X-ray diffraction analysis; monoclinic space group C2 with a = 22.1075(14), b = 6.491(2), c = 5.9570(4) A, β = 100.168(6)°. The 11B NMR spectrum is consistent with a mono-hetero-substituted octahedral B6 cage with local C4v symmetry. The IR and Raman spectra exhibit characteristic N–H, B–H and B6 vibrations.

Degradation-insertion reactions of decaborane(14) with inorganic salts

1983 ◽  
Vol 48 (9) ◽  
pp. 2593-2603 ◽  
Author(s):  
Karel Baše
Keyword(s):  
Diffraction Analysis ◽  
Nmr Spectra ◽  
Inorganic Salts ◽  
Analogous Reaction ◽  
X Ray Diffraction ◽  
Insertion Reactions ◽  
X Ray ◽  
Lewis Bases ◽  
H Nmr

Decaborane(14) reacts with NaNO2 in tetrahydrofuran forming the [9-tetrahydrofuran-6-NO2B10H12]- salt which after protonization with concentrated H2SO4 or diluted HCl affords azaboranes 6-NB9H12 and 4-NB8H13, respectively. The 6-NB9H12 azaborane is hydrolyzed to the 4-NB8H13 azaborane and reacts with Lewis bases under the formation of the 9-L-6-NB9H12 ligand derivatives (L = (CH)S, CHCN, (CH)P). By the reduction of 9-CHCN-6-NBH with LiAlH4 in tetrahydrofuran the 6-NB9H13- anion was prepared. By an analogous reaction of decaborane(14) with KHSO3 in water and by a subsequent protonization of the formed intermediate with concentrated H2SO4 or diluted HCl the thiaboranes 6-SB9H11 and 4-SB8H12, respectively, were prepared. The reaction of decaborane(14) with Na2SeO3 in tetrahydrofuran followed by the protonization of the intermediate with diluted HCl afforded the 7,8-Se2B9H9 species. Structures of all compounds were proposed on the basis of the 11B and 1H NMR spectra; in the case of 4-NB8H13, the structure was determined by the X-ray diffraction analysis.

Sign in / Sign up

Export Citation Format

Share Document