Bond dissociation energies of diatomic transition metal selenides: TiSe, ZrSe, HfSe, VSe, NbSe, and TaSe

作者：Sorensen Jason J; Persinger Thomas D; Sevy Andrew; Franchina Jordan A; Johnson Eric L; Morse Michael D

来源：Journal of Chemical Physics, 2016, 145(21): 214308.

DOI：10.1063/1.4968601

Predissociation thresholds have been observed in the resonant two-photon ionization spectra of TiSe, ZrSe, HfSe, VSe, NbSe, and TaSe. It is argued that the sharp onset of predissociation corresponds to the bond dissociation energy in each of these molecules due to their high density of states as the ground separated atom limit is approached. The bond dissociation energies obtained are D-0(TiSe) = 3.998(6) eV, D-0(ZrSe) = 4.902(3) eV, D-0(HfSe) = 5.154(4) eV, D-0(VSe) = 3.884(3) eV, D-0(NbSe) = 4.834(3) eV, and D-0(TaSe)= 4.705(3) eV. Using these dissociation energies, the enthalpies of formation were found to be Delta H-f,0K(o)(TiSe(g)) = 320.6 +/- 16.8 kJ mol(-1), Delta H-f,0K(o)(ZrSe(g)) = 371.1 +/- 8.5 kJ mol(-1), Delta H-f,0K(o)(HfSe(g)) = 356.1 +/- 6.5 kJ mol(-1), Delta H-f,0K(o)(VSe(g)) = 372.9 +/- 8.1 kJ mol(-1), Delta(f,) H-0K(o)(NbSe(g)) = 498.9 +/- 8.1 kJ mol(-1), and Delta H-f, 0K(o)(TaSe(g)) = 562.9 +/- 1.5 kJ mol(-1). Comparisons are made to previouswork, when available. Also reported are calculated ground state electronic configurations and terms, dipole moments, vibrational frequencies, bond lengths, and bond dissociation energies for each molecule. A strong correlation of the measured bond dissociation energy with the radial expectation value, h r i nd, for the metal atom is found. Published by AIP Publishing.

• 出版日期2016-12-21