Regularities in formation of intramolecular hydrogen bonds with the metal atom Part I.α-Metallocenylcarbinols of the iron subgroup

Conditions for the formation of intramolecular hydrogen bonds in α-metallocenylcarbinols of the iron subgroup (MFe, Ru, Os) are determined. The combination of IR spectral data with conformational calculations has revealed situations where hydrogen bonding with the metal atom is determined by conformational preference. General rules governing the influence of the nature of the metal atom and the effect of substituents in the carbinol group andthe cyclopentadienyl rings on the formation constants and relative stability of OH⋯M intramolecular hdyrogen bonds, on the proton-donating ability of the OH group and on the competition between intra- and inter-molecular hydrogen bonds during self-association in the crystal, are established.