With great sadness, we inform that
Dr Serge S. Tratch
passed away on July 17, 2023.

His entire life from a student to leading researcher was associated with the Lomonosov Moscow State University. After graduation, he started his career as a synthetic organic chemist, but then in 1974 he switched to mathematical chemistry and, working with Professor Nikolay Zefirov, commenced the development of the principles of the formal-logical approach to organic reactions. As a result, a large series of papers was published on the applications of the formal-logical approach to multi-center processes with cyclic electron transfer, to tautomeric processes with new topologies, to the generation of equations characterizing ionic, radical, and redox processes, to organic processes with open and linear-cyclic bond redistribution topologies. Finally, symbolic equations were introduced and their applications to reaction design were discussed. The proposed approach allows easy generation of new types of organic reactions with various bond redistribution topologies using computer programs developed by Dr Tratch, his colleagues and students. Dr Tratch also had suggested new topological indices, introduced a number of mathematical models in stereochemistry, and solved many other important problems in the field of mathematical chemistry. Dr Tratch was a member of IAMC since its foundation in 2005 and actively participated in several IAMC meetings.

He was our friend and colleague, a very pleasant and nice person. The cherished memory of Serge Tratch will remain forever in our hearts.

We express sincere condolences to his family and friends.

On January 9, 2023, we were all shocked and saddened by the news of a premature and tragic departure of our colleague, friend and teacher, Alireza Ashrafi. His life was cut short by a reckless driver who hit Alireza while he was crossing a street on his way home.

Alireza Ashrafi was born in 1964. After graduating at Kharazmi University in 1988, he obtained his MSc degree at the Shahid Beheshti University in 1990 and then earned his PhD degree in computational group theory in 1994 from the University of Tehran. He spent most of his career at the Department of Mathematics of University of Kashan in Kashan, teaching numerous courses, mentoring dozens of MSc and PhD students, writing hundreds of papers, starting and managing several journals, and, along the way, opening vast new areas of research for his students and colleagues.

This note cannot do justice to all of Alireza's work and achievements. One of the reasons is that I am not knowledgeable enough about several areas of his work. The other, more important, is that there is so much of it that it is difficult to obtain exact, or even approximate, numbers of papers, conferences, coauthors and PhD students. Hence, I will restrict myself to my personal impressions and recollections, in particular those relevant for his activity in the areas of mathematical chemistry and chemical graph theory.

I first met Alireza in April 2009, when he invited me to Kashan to the second in series of conferences and workshop in mathematical chemistry. My first impression, of a kind and gentle man, was amply reinforced by our subsequent interactions. Along with it, during our collaboration on several papers and research projects, grew also my respect for his scientific prowess. Above all, I was impressed by his respect and affection for his many PhD students, the feelings which were reciprocated by each and every of them.

The next year, 2010, saw the appearance of the first issue of the Iranian Journal of Mathematical Chemistry, a new journal serving the dynamic and rapidly growing area devoted to applications of discrete mathematics to problems of interest in chemistry. As its spiritus movens and its Editor-in-Chief, Alireza managed to keep and preserve a delicate balance between the opposing forces of the sterile ivory-tower elitism and greedy publish-or-perish culture. The journal grew in both quality and prestige and became a standard venue for publishing timely and relevant research. Similar success has been in making for Mathematics Interdisciplinary Research, another scientific journal Alireza helped to start and manage a couple of years later.

Alireza's great contribution to mathematical chemistry was recognized by his election to the International Academy of Mathematical Chemistry, where he actively participated in its governing bodies and served for one term as its vice-president.

Alireza left a great legacy both as a scientist and as a teacher. He was at his best by combining both roles. By sharing his network of international collaborators with his students, and by sharing his circle of young and talented Iranian mathematicians with his foreign colleagues, he has created a vibrant and closely-knit community of researchers which helped to make Iran not only visible but also a prominent actor in the global mathematical chemistry community.

To finish on a very personal note, I will be always thankful to Alireza for his first invitation. He and other Iranian colleagues opened to me not only their hearts and homes, but also a window into the soul of Iran, allowing me thus to fall in love with the country and with its people.

Thank you, Alireza, and may your soul rest in peace.

Tomislav Došlić

The Mathematical Institute of the Serbian Academy of Sciences and Arts, the Faculty of Sciences of the University of Kragujevac and the Department of Mathematics, Physics and Geosciences of the Serbian Academy of Sciences and Arts are jointly organising an international conference on chemical graph theory in Sombor, Serbia from June 3–5, 2022.

The conference is primarily organised to celebrate recent introduction of the codes 05C09 Graphical indices (Wiener index, Zagreb index, Randić index, etc.), and 05C92 Chemical graph theory in the Mathematics Subject Classification 2020, which recognise chemical graph theory as an independent subject area within graph theory.

The conference will be held in Sombor, Serbia. While Sombor is already well known for its greenery, cultural life and beautiful historical city center, it is quickly becoming famous among chemical graph theorists also for the recently introduced Sombor index.

Conference website: https://sites.google.com/view/cgtc2022

Monthly research seminar for biomathematics and mathematical chemistry is intended for formal and informal acquaintance with the latest achievements in the fields that intertwine the use of mainly discrete mathematical and computer methods in chemistry and biosciences. At the seminar, researchers and doctoral students report on their results. On the other hand, it also enables informal meetings of those interested in joint research work on concrete open problems.

Announcements: https://www.famnit.upr.si/sl/raziskovanje/seminarji/ma-bio-seminar

If you would like to contribute a talk, please contact Dr Nino Basic via email.