Thermodynamic evidence for quadruple bond formation in the molecule ThRu and possible maximum bond energy between ligand-free metal atoms

Abstract

The dissociation energies, D o o, of the molecules ThRu and RuC have been measured by high temperature Knudsen cell mass spectrometry as 140.5 ± 10 kcal mol −1 or 587.9 ± 42 kJ mol −1 and 154.0 ± 3 kcal mol −1 or 644.3 ± 12 kJ mol −1, respectively. The high value for the dissociation energy of ThRu indicates formation of a quadruple bond by this molecule. The maximum possible value of the bond energy between ligand-free metal atoms is estimated as 160 ± 20 kcal mol −1.