The thermally and chemically robust σ-alkane complex [Rh(Cy2PCH2CH2PCy2)(norborane)][B(3,5-(SF5)2C6H3)4] is characterized by micro-electron diffraction using on-grid single-crystal to single-crystal reactivity.

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., LnM(CO) + OH− → [LnM(CO2H)]−, M = Fe, Ru, Os, L = CO, PMe3, PF3, 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. Graphical abstractᅟ Electronic supplementary materialThe online version of this article (10.1007/s00894-018-3915-1) contains supplementary material, which is available to authorized users.