The X-ray structures of the redox-related pair [Co2(CO)2(µ-MeC2Me)(µ-dppm)2] and [Co2(CO)2(µ-MeC2Me)(µ-dppm)2][PF6], CH2Cl2(dppm = Ph2PCH2PPh2): an experimental test of the M.O. bonding scheme for the µ-alkyne complexes [M2(CO)6(µ-RC2R)]

1989 ◽  
pp. 33-35 ◽  
Author(s):  
R. Paul Aggarwal ◽  
Neil G. Connelly ◽  
M. Carmen Crespo ◽  
Barry J. Dunne ◽  
Philippa M. Hopkins ◽  
...  
Keyword(s):  
Experimental Test ◽  
X Ray ◽  
Related Pair ◽  
Alkyne Complexes ◽  
Bonding Scheme

Bis(1-phenyl-1-propyne) complexes of tungsten(II): crystal structures of [WI2(CO)(NCR)(η2-MeC2Ph)2] (R = Me, Et, or Ph)

2001 ◽  
Vol 79 (3) ◽  
pp. 263-271
Author(s):  
Paul K Baker ◽  
Michael GB Drew ◽  
Deborah S Evans
Keyword(s):  
Carbon Monoxide ◽  
Solid State ◽  
Crystal Structures ◽  
Octahedral Geometry ◽  
X Ray ◽  
X Ray Crystallography ◽  
Alkyne Complexes ◽  
First Time

Reaction of [WI2(CO)3(NCMe)2] with two equivalents of 1-phenyl-1-propyne (MeC2Ph) in CH2Cl2, and in the absence of light, gave the bis(1-phenyl-1-propyne) complex [WI2(CO)(NCMe)(η2-MeC2Ph)2] (1) in 77% yield. Treatment of equimolar quantities of 1 and NCR (R = Et, i-Pr, t-Bu, Ph) in CH2Cl2 afforded the nitrile-exchanged products, [WI2(CO)(NCR)(η2-MeC2Ph)2] (2-5) (R = Et (2), i-Pr (3), t-Bu (4), Ph (5)). Complexes 1, 2, and 5 were structurally characterized by X-ray crystallography. All three structures have the same pseudo-octahedral geometry, with the equatorial sites being occupied by cis and parallel alkyne groups, which are trans to the cis-iodo groups. The trans carbon monoxide and acetonitrile ligands occupy the axial sites. In structures 1 and 2, the methyl and phenyl substituents of the 1-phenyl-1-propyne ligands are cis to each other, whereas for the bulkier NCPh complex (5), the methyl and phenyl groups are trans to one another. This is the first time that this arrangement has been observed in the solid state in bis(alkyne) complexes of this type.Key words: bis(1-phenyl-1-propyne), carbonyl, nitrile, diiodo, tungsten(II), crystal structures.

Alkin-Komplexe des Rheniums in hohen Oxidationsstufen / Alkyne Complexes of Rhenium in High Oxidation States

1990 ◽  
Vol 45 (6) ◽  
pp. 876-886 ◽  
Author(s):  
Wolfgang A. Herrmann ◽  
Josef K. Felixberger ◽  
Josef G. Kuchler ◽  
Eberhardt Herdtweck
Keyword(s):  
Diffraction Study ◽  
Scale Up ◽  
Oxidation States ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reducing Conditions ◽  
Molar Amount ◽  
High Oxidation ◽  
Alkyne Complexes ◽  
Type 3

The class of π-alkyne complexes of metals in medium and high oxidation states has been extended by the type CH3ReO2(RC≡CR′) (3a—i). Exchange of alkyne for oxo ligands under reducing conditions has been employed as a new general synthesis. Compounds 3 are thus obtained by reaction of methyltrioxorhenium(VII) (1) with the alkynes 2a—i in the presence of a ca. 1.1-fold molar amount of polymer-bound triphenylphosphane as reducing agent (desoxygenation). The structural characterization was carried out for the example of the tolan complex 3 e by virtue of a single-crystal X-ray diffraction study at —80 °C, according to which the description of compounds 3 as “rhenacyclopropenes” seems justified. Evidence from NMR investigations of 3 a and 3 c shows that no fast rotation of the respective alkyne ligand around the axis to the metal atom occurs on the NMR time scale up to at least 105 °C. A minimal rotation barrier of approximately 20 kcal/mol is thus to be estimated. Reaction of type 3 compounds (R = R′ = CH3, b; R = R′ = C2H5, c) with polymer-bound triphenylphosphane under more drastic conditions (boiling toluene) for two days effects further reduction, with the dinuclear, diamagnetic rhenium(IV) complexes 4b and 4c, resp., being formed. Sterically demanding alkynes (e.g., R = R′ = Si(CH3)3, C6H5) seem to prevent this type of reaction. According to an X-ray diffraction study, 4b has an equilateral Re2O-triangular core geometry, with the ligands O, CH3, and butyne(2) arranged in such a way that C2-symmetry results. The alkyne complexes reported here are the first ones of tetra- and pentavalent rhenium.

H-bonding scheme in allactite: a combined single-crystal X-ray and neutron diffraction, optical absorption spectroscopy, FTIR and EPMA-WDS study

2016 ◽  
Vol 80 (5) ◽  
pp. 719-732 ◽  
Author(s):  
G. Diego Gatta ◽  
Ferdinando Bosi ◽  
Maria Teresa Fernandez Diaz ◽  
Ulf Hålenius
Keyword(s):  
Neutron Diffraction ◽  
Optical Absorption ◽  
Single Crystal ◽  
Absorption Spectroscopy ◽  
Structure Refinement ◽  
Site Occupancy ◽  
Optical Absorption Spectroscopy ◽  
Hydroxyl Groups ◽  
X Ray ◽  
Bonding Scheme

AbsatractThe crystal chemistry of allactite from Långban, Värmland (Sweden) was investigated by single-crystal X-ray and neutron diffraction, optical absorption spectroscopy, Fourier-transform infra-red spectroscopy (FTIR) and electron microprobe analysis by wavelength-dispersive spectroscopy (EPMA-WDS). The optical spectra indicate the presence of Mn in valence state 2+ only. Assuming 16 O atoms per formula unit, arsenic as As5+and the (OH) content calculated by charge balance, the resulting formula based on the EPMA-WDS data is (Mn2+6.73Ca0.13Mg0.12Zn0.02)∑7.00(As5+)2.00O16H8, very close to the ideal composition Mn7(AsO4)2(OH)8. In the unpolarized FTIR spectrum of allactite, fundamental (OH)-stretching bands are observed at 3236, 3288, 3387, 3446, 3484, 3562 and 3570 cm–1, suggesting that a number of OH environments, with different hydrogen bond strengths, occur in the structure. The neutron structure refinement shows that four independent H sites occur in allactite with full site occupancy, all as members of hydroxyl groups. The complex hydrogen-bonding scheme in the allactite structure is now well defined, with at least nine hydrogen bonds energetically favourable with mono-, bi- and trifurcated configurations.

Refinement of the layered titanosilicate AM-1 from single-crystal X-ray diffraction data

2007 ◽  
Vol 63 (11) ◽  
pp. i186-i186 ◽  
Author(s):  
Stanislav Ferdov ◽  
Uwe Kolitsch ◽  
Christian Lengauer ◽  
Ekkehart Tillmanns ◽  
Zhi Lin ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Hydrogen Bonding ◽  
Single Crystal ◽  
Single Crystals ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Time ◽  
Ir And Raman ◽  
Bonding Scheme

The structure of the layered noncentrosymmetric titanosilicate AM-1 (also known as JDF-L1, disodium titanium tetrasilicate dihydrate), Na4Ti2Si8O22·4H2O, grown as small single crystals without the use of organics, has been refined from single-crystal X-ray diffraction data. The H atom has been located for the first time, and the hydrogen-bonding scheme is also characterized by IR and Raman spectroscopy. All atoms are in general positions except for the Na, the Ti, one Ti-bound O, one Si-bound O and the water O atoms (site symmetries 2, 4, 4, 2 and 2, respectively).

The X-ray crystal structure of N-(1-octyl)-d-talonamide and a consideration of its hydrogen-bonding scheme

1993 ◽  
Vol 240 ◽  
pp. 47-56 ◽  
Author(s):  
Christoph André ◽  
Peter Luger ◽  
Sönke Svenson ◽  
Jürgen-Hinrich Fuhrhop
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
X Ray ◽  
Bonding Scheme

Organorheniumhalogenide: Synthesen, Strukturen und Reaktivität gegenüber Alkinen / Organorhenium Halogenides: Synthesis, Structure and Reactivity upon Treatment with Alkynes

1988 ◽  
Vol 43 (11) ◽  
pp. 1391-1404 ◽  
Author(s):  
Wolfgang A. Herrmann ◽  
Roland A. Fischer ◽  
Josef K. Felixberger ◽  
Rocco A. Paciello ◽  
Pavlo Kiprof ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Single Bond ◽  
X Ray Diffraction ◽  
Alkyl Aryl ◽  
X Ray ◽  
Aluminium Powder ◽  
Metal Metal ◽  
Related Derivative ◽  
Alkyne Complexes ◽  
Powder Forming

The organorhenium(V) complexes (η5-C5Me5)ReX4 (2a, X = Cl; 2b, X = Br; Me = CH3) undergo stepwise dehalogenation upon treatment with various reducing agents, e.g. with HgCl2-activated aluminium powder, forming the isolable ReIV and ReIII dimers [η5-C5Me5)ReCl3]2 (3a) and [η5-C5Me5)ReX2]2 (4a, X = Cl;4b, X = Br), respectively. The weak metal-metal single bond of 3a (307.4(0) pm; X-ray diffraction study) is disrupted upon reaction with alkynes yielding the ReIII derivatives (η5-C5Me5)ReCl2(η2-R1CCR2) (9a-e; R1, R2: alkyl, aryl) and novel rhenium(V)- allylidenyl complexes of type (η5-C5Me5)ReCl2[η1:η3-R1CC(Cl)CHR3] (10a-d; R1: alkyl. aryl; R3: H, alkyl). Reduction of 2a (Al/HgCl2) in the presence of alkynes gives a complex reaction mixture of 9a-c, 10a - c and bis(π-alkyne) complexes [(η5-C5Me5)ReCl(η2-R1CCR2)2] + [AlCl4]-(11a-c) (X-ray diffraction study of the related derivative [(η5-C5Me5)ReBr(η2-MeCCMe)2] + [SbF6]-).

Niobocene Alkyne Complexes:  Synthesis and Characterization of Neutral and Cationic d2Metal Alkyne Derivatives. X-ray Crystal Structure of [Nb(η5-C5H4SiMe3)2(η2(C,C)-HC⋮CPh)(CH2Ph)]

1997 ◽  
Vol 16 (12) ◽  
pp. 2601-2611 ◽  
Author(s):  
Antonio Antiñolo ◽  
Antonio Otero ◽  
Mariano Fajardo ◽  
Cristina García-Yebra ◽  
Carmen López-Mardomingo ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Synthesis And Characterization ◽  
X Ray ◽  
Alkyne Complexes ◽  
Alkyne Derivatives
Sign in / Sign up

Export Citation Format

Share Document