C−H Activation by AlCl Monomers: Characterization of HAl(Cl)CH 3 as the Product of the Photoactivated Reaction Between AlCl and CH 4 in a Solid Ar Matrix at 12 K

In a solid Ar matrix at 12 K and upon photoactivation AlCl inserts into the C−H bond of CH 4 to give the new monomeric aluminium hydride HAl(Cl)CH 3 , which was identified and characterized with the aid of the IR spectra recorded for several isotopomers [Cl(H)Al 12 CH 3 , Cl(D)Al 12 CD 3 , and Cl(H)Al 13 CH 3 ], comparison with the known IR properties of related molecules and detailed quantum chemical calculations. Calculations yield a C s symmetric global energy minimum structure for this compound, and that the reaction is slightly exothermic (reaction energy of −43.2 kJ·mol −1 ). This work demonstrates impressively how reactive photoactivated AlCl molecules are. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)