Professor Eduard Hála was one of the most prominent and influential thermodynamicists of the twentieth century who along with his alter ego, Arnošt Reiser, founded and shaped the Czechoslovak school of physical chemistry. He was born in 1919, the same year in which the IUPAC was founded, so in 2019, as the IUPAC was celebrating its 100th anniversary, it seemed, at least for us, logical to commemorate his life and devoted research carrier in a symposium organized during the 47th IUPAC World Chemistry Congress at Palais des Congrès in Paris on the 10th July 2019.

The session welcomed Karel Aim, Hála’s pupil and long-term collaborator who talked to us about Hála’s extraordinary life, personality, and the way he influenced entire generations of physical chemists in Czechoslovakia and beyond. Dr. Aim’s keynote talk was followed by excellent contributions by Emmerich Wilhelm (Vienna University), Alex de Visscher (Concordia University), Richard Darton (Oxford University), Jean-Noël Jaubert (Université de Loraine), Luis Santos (University of Porto), Andreas Klamt (formerly COSMOlogic, now retired), and last, but not least another of Hála’s pupils Zdeněk Wagner (Institute of Chemical Process Fundamentals of the CAS). As a pre-symposium, Hála the musician was also deeply celebrated by an organ recital, at the St. Antoine des Quinze-Vingts on the 8th July 2019, given by Jan Rotrekl, then the youngest member of the research group of Thermodynamics of Task-Specific, which that takes its roots in the original Eduard Hála Laboratory of Thermodynamics.

This special issue is opened by the commemorative paper by Karel Aim followed by a sweeping review of solution chemistry “Solutions, in Particular Dilute Solutions of Nonelectrolytes: A Review” by Emmerich Wilhelm and by a new take on the Specific Ion Theory “Extended Specific Ion Theory (ESIT): Theoretical Development and Application to Harned’s Rule” by Alex de Visscher. These contributions along with those delivered at the Hála Symposium in Paris show that, although Eduard Hála spent the entirety of his life beyond the Iron Curtain, he was able to inspire and will stimulate his fellow researchers for decades on.