Etude de complexes acide de Lewis–halogénure d'acide. III. Structure cristalline du composé moléculaire chlorure d'aluminum–chlorure de propionyle

Carpentier, J. M. Le; Weiß, Richard

doi:10.1107/s056774087200442x

Cited by 23 publications

(5 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The acetyl cation (H 3 CCO + ) may be viewed as CO coordinated to a nearly pure σ-acceptor cation, CH 3 + . Our calculations on H 3 CCO + yield equilibrium H 3 C−CO and C−O bond distances of 1.439 Å and 1.127 Å, in good agreement with the experimental value for this (1.435 Å and 1.099 Å, respectively) , and related acylium cations. ,, The value of F CO is found to be 19.61 mdyn/Å, 1.2 mdyn/Å larger than its value in free CO. By comparison, H*CO + has an F CO value of 20.15 mdyn/Å when r H*C is held fixed at 1.44 Å. Thus, in this case, as in the above comparison of H*CO with HCO + , “turning on” σ-bonding apparently has a slightly diminishing effect on the value of F CO .…”

Section: Resultssupporting

confidence: 84%

Why Do Cationic Carbon Monoxide Complexes Have High C−O Stretching Force Constants and Short C−O Bonds? Electrostatic Effects, Not σ-Bonding

1996

View full text Add to dashboard Cite

A significant increase in the C−O stretching force constant (F CO) and a decrease in C−O bond length (r CO) result upon coordination of carbon monoxide to various cationic species. We report a study designed to elucidate the factors responsible for this effect. In particular, we distinguish between an explanation based on electrostatic effects and one based on withdrawal of electron density from the 5σ orbital of CO, an orbital generally considered to have some antibonding character. Ab initio electronic structure calculations on CO in the presence of a positive point charge (located on the carbon side of the bond axis) reveal that a simple Coulombic field increases the C−O stretching force constant and decreases the bond length. Coordination of CO to a simple cationic Lewis acid such as H+ or CH3 + is calculated to increase F CO (and decrease r CO) to extents slightly less than those engendered by a point charge at the same distance from the carbonyl carbon. These results indicate that electron donation from the 5σ orbital has no intrinsic positive effect on the magnitude of F CO. Calculations were also conducted on several symmetrical, neutral, and cationic transition metal complexes, including some examples of the recently discovered homoleptic noble-metal carbonyls. It is found that F CO values can be quantitatively interpreted using a model which invokes only the effects of M−CO π-back-bonding and an electrostatic parameter. There is no correlation between the extent of σ-bonding (as measured by the depopulation of the CO σ orbitals) and F CO. Calculations on trigonal bipyramidal d8 metal pentacarbonyls permit a comparison between inequivalent ligands (axial and equatorial) which, being coordinated to the same metal center, must experience approximately the same electrostatic field. In the case of Ru(CO)5, π-back-bonding to the axial and equatorial carbonyls is of virtually equal magnitude, while σ-donation is much greater from the axial ligands than from the equatorial ligands. Nevertheless, the F CO and r CO values of the two ligand sets are essentially equal, confirming that the magnitude of σ-donation does not affect these parameters.

show abstract

Section: Resultssupporting

confidence: 84%

Why Do Cationic Carbon Monoxide Complexes Have High C−O Stretching Force Constants and Short C−O Bonds? Electrostatic Effects, Not σ-Bonding

1996

View full text Add to dashboard Cite

show abstract

“…94 The structures of MeCO + AlC£, 97 and RC(C1) = O-»A1C1 3 [R = Et, 98 C6H5," and o-and p-MeC^1 00 ] were determined by X-ray diffraction analysis. The cationic fragment MeCO + in the ionic complex MeCO + AlCl4 is linear, which corresponds to jp-hybridisation of the carbonyl carbon atom.…”

Section: The Nature Of the Active Complexes In Acyl Halide -Aluminmentioning

confidence: 99%

Low-temperature functionalisation of alkanes and cycloalkanes by 'classical' and 'non-classical' (superacidic) Friedel–Crafts complexes

Akhrem¹,

Orlinkov²,

Vol'pin³

1996

Russ. Chem. Rev.

View full text Add to dashboard Cite

Low-temperature functionalisation of alkanes and cydoalkanes by 'classical' and 'non-classical' (superaddic) Friedel-Crafts complexesI S Akhrem, A V Orlinkov, M E Vol'pin (deceased) Contents I. Introduction 849 II. Functionalisation of isoalkanes and activated cydoalkanes by equimolar complexes RCOX -AlCb and related systems 850 III. Functionalisation of alkanes and cydoalkanes with aprotic organic superaddic complexes RCOX -2A1C1 3 853 IV. Reactions of acylium salts with saturated hydrocarbons in protic superacids 857 V. The nature of the active complexes in acyl halide -aluminium halide systems 858 VI. Conclusion 862 Abstract. The results of studies on direct functionalisation of activated alkanes and cydoalkanes under the action of 'classical' Friedel-Crafts complexes (viz. equimolar complexes of acyl halides with aluminium halides) and related systems containing smaller or somewhat larger amounts of aluminium halide are surveyed. The studies carried out during the last decade on functionalisation of saturated hydrocarbons devoid of tertiary carbon atoms, by aprotic organic superacids RCOX-2AICI3 are summarised. Reactions of alkanes with acylium cations in superacidic media are considered. The published data on the structure of complexes RCOX • AICI3 and RCOX • 2A1C1 3 and on the nature of the active complexes in the reactions of arenes with acylium cations and with complexes RCOX-AICI3 in both acidic and organic media as well as in the reactions of alkanes with acylium salts in protic superacids and with superaddic complexes RCOX -2AICI3 in aprotic solvents are analysed. The prospects for the synthesis of organic compounds from alkanes and cydoalkanes under the action of complexes of acyl halides with aluminium halides are outlined. The bibliography includes 128 references. IS Akhrem, A V Orlinkov Laboratory of complex organometallic catalysts, Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sdences, ul. Vavilova 28,117813 Moscow, Russian Federation. Fax (7-095) 135 50 85 Vol'pin M E Director of the same Institute Received 15 April 1995 Vspekhi Khimii 65 (10) 920-935 (1996); translated by Z P Bobkova

show abstract

“…Crystal structure data areavailable for somecompounds RCOCl .AICI, (R = aliphatic or aromatic radical). On the basis of these data [27,281 we chose the 0-Ga-CI angle 8 = 104.5" for benzophenone . GaC1, and for 4-chlorophenol .…”

Section: Charge Transfer In Compounds L Gaclmentioning

confidence: 99%

Charge Distribution and Donor Properties in Complexes L·Me^IIIX₃ (L  ArCOAr, ArCOCl, ArOH; Me^III  Al, Ga; X  Cl, Br) and (ArOAlBr₂)_x. An NQR (³⁵Cl, ⁸¹Br, ⁶⁹Ga) and IR (ṽ(C  O), ṽ(CCl)) Investigation

Deeg¹,

Weiß²

1976

Ber Bunsenges Phys Chem

View full text Add to dashboard Cite

Molecular compounds of the type L · MeX3 (L  benzophenones, benzoylchlorides, 4‐chlorophenol; MeX3  AlBr3, AlCl3, GaCl3) were studied by NQR and IR spectroscopy. Also, in two compounds of the type chlorophenoxy aluminumdibromide the halogen NQR was investigated. On the basis of the 35Cl and 81Br NQR experiments, benzoylchlorides appear to be weaker donors than benzophenones are. Yet, the shift of the carbonyl stretching frequency due to the formation of the complexes is less for benzophenones. In adducts of benzoylchlorides with AlCl3 the shift of the 35Cl NQR frequency (assigned to Cl linked to the carbonyl C atom), Δv(35Cl), and the shift of the CCl stretching frequency, Δṽ(CCl), were measured. A positive correlation of Δv(35Cl) with Δṽ(CCl) was found. On the basis of the 69Ga and 35Cl NQR frequencies measured for some molecular compounds L · GaCl3 the charge transfer was estimated with the aid of the Townes and Dailey Theory. A comparison with results obtained analogously for inorganic complexes incorporating GaCl3 is given. From the NQR experiments conclusions concerning the structure of the compounds investigated were drawn.

show abstract

Etude de complexes acide de Lewis–halogénure d'acide. III. Structure cristalline du composé moléculaire chlorure d'aluminum–chlorure de propionyle

Cited by 23 publications

References 1 publication

Why Do Cationic Carbon Monoxide Complexes Have High C−O Stretching Force Constants and Short C−O Bonds? Electrostatic Effects, Not σ-Bonding

Why Do Cationic Carbon Monoxide Complexes Have High C−O Stretching Force Constants and Short C−O Bonds? Electrostatic Effects, Not σ-Bonding

Low-temperature functionalisation of alkanes and cycloalkanes by 'classical' and 'non-classical' (superacidic) Friedel–Crafts complexes

Charge Distribution and Donor Properties in Complexes L·Me^IIIX₃ (L  ArCOAr, ArCOCl, ArOH; Me^III  Al, Ga; X  Cl, Br) and (ArOAlBr₂)_x. An NQR (³⁵Cl, ⁸¹Br, ⁶⁹Ga) and IR (ṽ(C  O), ṽ(CCl)) Investigation

Contact Info

Product

Resources

About

Etude de complexes acide de Lewis–halogénure d'acide. III. Structure cristalline du composé moléculaire chlorure d'aluminum–chlorure de propionyle

Cited by 23 publications

References 1 publication

Why Do Cationic Carbon Monoxide Complexes Have High C−O Stretching Force Constants and Short C−O Bonds? Electrostatic Effects, Not σ-Bonding

Why Do Cationic Carbon Monoxide Complexes Have High C−O Stretching Force Constants and Short C−O Bonds? Electrostatic Effects, Not σ-Bonding

Low-temperature functionalisation of alkanes and cycloalkanes by 'classical' and 'non-classical' (superacidic) Friedel–Crafts complexes

Charge Distribution and Donor Properties in Complexes L·MeIIIX3 (L  ArCOAr, ArCOCl, ArOH; MeIII  Al, Ga; X  Cl, Br) and (ArOAlBr2)x. An NQR (35Cl, 81Br, 69Ga) and IR (ṽ(C  O), ṽ(CCl)) Investigation

Contact Info

Product

Resources

About

Charge Distribution and Donor Properties in Complexes L·Me^IIIX₃ (L  ArCOAr, ArCOCl, ArOH; Me^III  Al, Ga; X  Cl, Br) and (ArOAlBr₂)_x. An NQR (³⁵Cl, ⁸¹Br, ⁶⁹Ga) and IR (ṽ(C  O), ṽ(CCl)) Investigation