Journal article

Authors list: Schreiner, PR; Schaefer, HF; Schleyer, PV

Publication year: 1995

Pages: 5565-5569

Journal: The Journal of Chemical Physics

Volume number: 103

Issue number: 13

ISSN: 0021-9606

DOI Link: https://doi.org/10.1063/1.470540

Publisher: American Institute of Physics

Abstract: 
Six candidate AlH5 structures were examined in detail using the self-consistent-field (SCF), configuration interaction including single and double excitations (CISD), and coupled cluster including single, double and perturbatively included connected triple excitations [CCSD(T)] methods in conjunction with double-zeta plus polarization (DZP), triple-zeta plus polarization (TZ2P), and augmented TZ2P(f,d) basis sets. The C-4v and the D-3h isomers are high in energy [72 and 84 kcal mol(-1), respectively, relative to the C-s(I) structure at DZP CCSD]. Although structure C-s(I) is the global minimum, the second C-s form, where AlH5 is comprised of nearly planar alane (AlH3) and dihydrogen, is essentially equal in energy. Hence, the rotation of the hydrogen moiety is virtually free. The global C-s(I) minimum was characterized by vibrational frequency analyses at TZ2P CCSD(T). Final energies were obtained at CCSD(T) TZ2P(f,d). At room temperature, the alane-dihydrogen complex AlH5 is unstable toward dissociation by 3.1 kcal mol(-1). However, at the absolute zero (0 K), the complex forms exothermically (-1.7 kcal mol(-1)). Hydrogen scrambling via the C-2v (3) transition structure seems to be very unlikely since the activation barrier for this process is at least 24.6 kcal mol(-1) higher than the dissociation energy of AlH5 into AlH3 and H-2.

Harvard Citation style: Schreiner, P., Schaefer, H. and Schleyer, P. (1995) Can AlH5 exist?, The Journal of Chemical Physics, 103(13), pp. 5565-5569. https://doi.org/10.1063/1.470540

APA Citation style: Schreiner, P., Schaefer, H., & Schleyer, P. (1995). Can AlH5 exist?. The Journal of Chemical Physics. 103(13), 5565-5569. https://doi.org/10.1063/1.470540