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

Shahbaz Ahmad, Elisabeth A. Berry, Conor H. Boyle, Christopher G. Hudson, Oliver W. Ireland, Emily A. Thompson, Michael Bühl
2019 Journal of Molecular Modeling  
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
more » ... m 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. Scheme 2 General mechanism for transition-metal-catalyzed WGSR under basic conditions, where OH − is the nucleophile Scheme 1 Putative reaction sequence for complete methanol dehydrogenation 45 Page 2 of 8 J Mol Model (2019) 25: 45
doi:10.1007/s00894-018-3915-1 fatcat:qacw5bsgnvhk7jihdaanunoq2y