13595-81-8Relevant articles and documents
Characterization of the side-on coordinated bissuperoxo complexes of aluminum FAI(O2)2, CIAI(O2)2, and BrAI(O2)2 with triplet electronic ground states: A combined matrix IR and quantum chemical study
Bahlo, Jan,Himmel, Hans-Joerg,Schnoeckel, Hansgeorg
, p. 4488 - 4495 (2002)
Matrix isolation has been used to study the photolytically induced reaction of AIX (X = F, Cl, or Br) with 02. The peroxo and bisperoxo compounds XAIO2 and XAI(O2)2 are found to be the products of these reactions. While the peroxo species XAIO2 were already addressed in a separate work, we concentrate herein on the bissuperoxo complexes XAI(O2)2, which are to our knowledge the first examples of such complexes with Al centers. Our IR spectroscopic results taking in the effect of isotopic substitution (16O/18O) allied with quantum chemical calculations show that the O2 moieties in these complexes are side-on coordinated, leading to an overall C2v symmetry of the complexes and a spin multiplicity of 3. The O-O distance of about 1.366 A argues for the presence of superoxide units. The force constants are, however, somewhat smaller than expected for a superoxide anion and indicate that the bonding in the complexes cannot be described simply on the basis of an ionic model. Interestingly a photoinduced intramolecular isotopic scrambling process is observed for the compounds resulting in partial conversion of the XAl(16O2)(18O)2 isotopomer into XAl(16O18O)(16O18O). The properties of the complexes will be compared to those of complexes to transition metal centers.
Microwave spectra of metal chlorides produced using laser ablation
Hensel, Kristine D.,Styger, Christian,Jaeger, Wolfgang,Merer, A. J.,Gerry, M. C. L.
, p. 3320 - 3328 (1993)
An apparatus has been constructed to produce metal compounds using laser ablation and to investigate their rotational spectra with a microwave Fourier transform (MWFT) cavity spectrometer.The first three such compounds that have been studied are silver chloride, aluminum (I) chloride, and copper (I) chloride, produced by ablation of silver, aluminum, and copper rods in the presence of chlorine gas, using a Q-switched Nd:YAG laser (532 nm).The high resolution and sensitivity available with the MWFT cavity spectrometer have permitted the first determination of nuclear spin-rotation coupling constants for AlCl and CuCl.These constants have been used to examine the electronic structures of the molecules.Values of the rotational and nuclear quadrupole coupling constants have also been improved for the three metal chlorides.
Characterization of oligomers of AlCl: Al-Cl versus Al-Al bonding
Himmel, Hans-Joerg
, p. 1886 - 1894 (2005)
Oligomers of AlCl have been characterized. By using the matrix isolation technique, the dimer Al2Cl2, which exhibits a Aursyrnmetric ring structure, was generated in significant quantities and analyzed by its IR and Raman spectra in combination with quantum chemical calculations. The structures of the trimer and tetramer have also been evaluated. A surprising result is that the minimum energy structure of the trimer (Cs symmetry) features direct Al-Al bonds, two terminal Al-Cl bonds, and one bridging Cl atom. A weak, isotopically structured IR band can be assigned to the antisymmetric v(Al-Clt) mode of this trimer (Cl t denotes a terminal Cl atom). The enthalpy change for each of the oligomerization steps has been calculated. For the dimerization of AlCl to give Al2Cl2, the Gibbs energy change was calculated as a function of temperature at different pressures. It turns out that neither the Al2Cl2 dimer nor any higher oligomers are present in significant quantities in the gas phase, at least under the conditions of the experiments. The thermodynamic properties show that matrix isolation represents the optimal method of generating and characterizing these species. On the basis of the experimental results the barrier for dimerization of AlCl should be next to zero. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
