What kind of interactions we may get moving from zwitter to “dritter” ions: C–O⋯Re(O4) and Re–O⋯Re(O4) anion⋯anion interactions make structural difference between l-histidinium perrhenate and pertechnetate

Abstract

L-Histidinium perrhenate was synthesized by the reaction of magnesium perrhenate with the corresponding nitrogenous base in hydrochloric acid. Pertechnetate was obtained from the nitrous base by reaction with pertechnetic acid. Their crystal structure was studied using single-crystal XRD and a comparative analysis of noncovalent interactions in the obtained structures was carried out. Pertechnetate is the second example of the combination of technetium with this amino acid, and both compounds described in this work are the first examples of structures of tetrahedral transition metal anions with histidine. The histidine molecules in the present structures are in the open conformation (1)(g−). Not only are nitrogen atoms of imidazole rings and amino groups involved in the formation of N–H⋯O type hydrogen bonds, but also CH group atoms form weaker C–H⋯O type hydrogen bonds. Histidinium perrhenate contains anion⋯anion interactions, including those described for the first time: C–O⋯Re(O₄) between the carboxyl group and the rhenium atom of the perrhenate anion. This type of interaction can be found (but was not discussed) in other Re and Mn compounds but is absent for Tc. Hirshfeld surface analysis showed that the most important contribution to the packing organization is made by the O⋯H/H⋯O interaction for cations and anions.