Formation of metallacarboxylic acids through Hieber base reaction. A density functional theory study

Using density functional theory (B97-D/ECP2/PCM//RI-BP86/ECP1 level), we have studied the effects of ligand variation on OH(−) uptake by transition-metal carbonyls (Hieber base reaction), i.e., L(n)M(CO) + OH(−) → [L(n)M(CO(2)H)](−), M = Fe, Ru, Os, L = CO, PMe(3), PF(3), py, bipy, Cl, H. The viability of this step depends notably on the nature of the co-ligands, and a large span of driving forces is predicted, ranging from ΔG = −144 kJ/mol to +122 kJ/mol. Based on evaluation of atomic charges from natural population analysis, it is the ability of the co-ligands to delocalize the additional negative charge (through their π-acidity) that is the key factor affecting the driving force for OH(−) uptake. Implications for the design of new catalysts for water gas shift reaction are discussed. [Figure: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00894-018-3915-1) contains supplementary material, which is available to authorized users.