Northwestern mourns Professor Emeritus Mark A. Ratner

Mark A. Ratner, the Lawrence B. Dumas Distinguished University Professor Emeritus in the Weinberg College of Arts and Sciences at Northwestern University, passed away on May 10 at age 83. He will be remembered as a brilliant scientist, enthusiastic researcher, supportive colleague and dedicated mentor.

Widely recognized as the “father of molecular electronics,” Ratner ’69 Ph.D. was a pioneering figure in theoretical chemistry whose work reshaped how scientists think about electronics at the smallest scales. In the 1970s, he showed, for the first time, that individual molecules could carry an electric current. At the time, this idea seemed almost implausible but since has become foundational to the field of nanoscience. That bold, seemingly improbable discovery laid the groundwork for designing tiny, molecular-scale circuits and devices that could power futuristic technologies, including molecular computers and quantum devices.

Over the decades, Ratner’s research spanned electron transfer, nanoscale transport and energy processes in complex systems, offering a unifying framework for understanding how electric charges move through matter. His insights not only advanced fundamental science but also opened the door to new technologies, built molecule by molecule. The impact of this work has rippled outward beyond the field of chemistry, influencing disparate disciplines from materials science to nanotechnology to computer engineering and more.

“Mark was wonderful man, a dear friend and a terrific scientist who had a tremendous impact on the worlds of chemistry, nanoscience, molecular electronics — and on Northwestern,” said Interim President and President Emeritus Henry S. Bienen. “My wife Leigh and I are very saddened to hear of his passing and send our condolences to Nancy and Mark’s entire family.”

Path to Northwestern

Born in 1942, Ratner grew up in Cleveland, Ohio, and often spent summers on Lake Erie. After earning a bachelor’s degree from Harvard University, Ratner joined Northwestern for the first time as a doctoral student in chemistry. From there, his career took him across the ocean to Germany and Denmark and eventually back to the United States, where he joined New York University as an assistant professor. But in 1974, Northwestern called, and Ratner seized the opportunity to return to the Midwest and to his family and friends.

At Northwestern, Ratner quickly rose to prominence as one of the University’s most influential scholars and educators. He twice chaired the department of chemistry and served as Weinberg’s associate dean and interim dean. Over the course of his career, he taught general chemistry to roughly 5,000 students. With his dedicated, encouraging mentorship, Ratner left a lasting imprint on others both through his ideas and through the generations of scientists and thinkers he helped train.

“Mark’s impact on his field and his department was profound,” said Weinberg Dean Adrian Randolph. “From his time as associate dean to his role as interim dean before my arrival, he dedicated himself fully to Weinberg College and to the virtues that are the foundation of our enterprise: compassion, generosity and a shared responsibility to one another. I feel incredibly fortunate that it was through his example that I received my welcome and introduction to the college. That spirit of care and commitment will be his lasting legacy.”

A career marked with honor

For his many scientific achievements, Ratner was recognized by the scientific community time and time again. He was inducted into the National Academy of Sciences, American Academy of Arts and Sciences, International Academy of Quantum Molecular Sciences and Royal Danish Academy of Sciences. He received the prestigious Langmuir and Gibbs Awards from the American Chemical Society and the Feynman Award from the Foresight Institute. Ratner also received honorary doctoral degrees from the University of Copenhagen and the Hebrew University of Jerusalem.

But, out of all his academic awards, Ratner was most proud of the honors that recognized his teaching. He was a member of Northwestern’s Faculty Teaching Honor Roll 11 times and received the Office of the Provost’s University Distinguished Teaching Award, given to faculty members whose sheer dedication to teaching transforms undergraduate learning. To honor this commitment, Northwestern established the Mark and Nancy Ratner Professorship. Former Northwestern chemistry professor and alumna Emily Weiss ’05 Ph.D received the inaugural professorship in 2018.

“I can think of no greater honor than the distinction of being the Mark and Nancy Ratner Professor,” Weiss said at the time. “And it’s even more special given that Mark is one of my primary influences, as a scientist and as a person. The Ratners have always been so generous to Mark’s students and colleagues and have always made them feel like family.”

A culture of curiosity and collaboration

Beyond his pioneering research, Ratner was known for his big, infectious smile and warm personality, bringing joy wherever he went. Ratner was a rare academic who paired visionary science with an instinct for building communities. During his four decades at Northwestern, Ratner proved himself as a generous mentor and trusted collaborator whose influence extended far beyond his own laboratory. He embraced new ideas and new people, helping to shape a culture of curiosity, ambition and collegiality that continues to define the department of chemistry to today.

“Those who knew Mark will remember far more than his scientific achievements,” said Omar K. Farha, professor and chair of the chemistry department. “He was deeply generous with his time, endlessly curious and uniquely gifted at making others feel valued. He had the rare ability to challenge and encourage simultaneously, leaving an indelible mark on everyone fortunate enough to work alongside him.”

“Mark and I shared a large number of bright and productive joint thesis students and postdocs, who stretched our minds and pushed our science beyond the frontiers,” said Tobin J. Marks, the Vladimir N. Ipatieff Professor of Catalytic Chemistry and chemical and biological engineering. “We jointly published 132 papers on topics ranging from pi-pi interactions in 1984 to nonlinear optics, plastic solar cells, transistor gate dielectrics and the last in 2020 on two-dimensional materials. It was thrilling to work with someone so bright and creative — a true scholar and caring person. Mark contributed so much to the chemistry department and to Northwestern. His memory will live on.”

Visionary builder

Ratner’s impact on Northwestern is woven into the University’s very fabric. He was a driving force behind the creation and growth of multiple institutes and centers, including the International Institute for Nanotechnology (IIN) and Chemistry of Life Processes Institute. He helped rally support, secure resources and articulate a vision that transformed Northwestern into a global leader in nanoscience. Since Ratner’s early support and ambitious vision, Northwestern’s investment in nanoscience has grown into one of the world’s largest and most influential nanoscience ecosystems, encompassing hundreds of affiliated faculty members, billions of dollars in research infrastructure and a culture built around interdisciplinary collaboration.

“Mark was a close friend, mentor and one of the driving forces behind the IIN,” said Chad A. Mirkin, IIN’s founding director and the George B. Rathmann Professor of Chemistry. “The two of us approached President Bienen and asked him to make a bet on nanoscience, and he did. Mark helped shape the future of IIN. He united administrators, philanthropists and faculty and worked hard to raise the resources to build our institute. The fact that it became one of the largest nanotechnology institutes in the world has a lot to do with him. Northwestern is a different and better place because of him.”

Along with David C. Dunand, a professor of materials science and engineering at the McCormick School of Engineering, Ratner served as the founding co-director of the Initiative for Sustainability and Energy at Northwestern (ISEN), now the Paula M. Trienens Institute for Sustainability and Energy. He also was founding co-director of Northwestern’s Center for Nanofabrication and Molecular Self-Assembly, one of the first federally and privately funded nanotechnology facilities of its kind.

“Professor Ratner was an inspired and inspiring scientist who nurtured multiple generations of scholars as well as Northwestern’s global excellence in chemistry and beyond,” said Ted Sargent, executive director of the Trienens Institute and the Lynn Hopton Davis and Greg Davis Professor of Chemistry. “Professor Ratner co-led ISEN, the precursor to the Trienens Institute, during its crucial development years from 2008 to 2013, in partnership with his co-director Professor David Dunand. Northwestern’s bold investment in ISEN, and Ratner and Dunand’s foundational leadership, led to the transformative gift announced in 2023 that the Institute would become the Paula M. Trienens Institute for Sustainability and Energy. At the Trienens Institute, we are all saddened by the loss of this great thought leader and colleague, but we continue to celebrate his vision and his legacy.”

Growth at Northwestern

Beyond the new centers and institutes, Northwestern grew exponentially during Ratner’s tenure. He witnessed — and helped drive — a remarkable transformation as Northwestern expanded its research enterprise, deepened its interdisciplinary culture and reached the top tier of global universities. To accommodate Northwestern’s explosive growth in chemistry and nanoscience, the University invested in new buildings, including Ryan Hall. Colleagues credit Ratner with helping attract exceptional researchers and recognizing emerging talent.

“Mark was the key person responsible for recruiting me to Northwestern 50 years ago,” said George Schatz, a Charles E. and Emma H. Morrison Professor of Chemistry. “When I first arrived, the chemistry department was probably ranked around 15th in the nation. But with the growth of nanoscience, the new buildings and the ability to recruit top faculty, Northwestern chemistry began to emerge in a much bigger way. Since around 2010, the department has often been ranked in the top five. Long after Mark retired, his importance to the scientific community has remained, which is something I encounter all the time at meetings and other events. He will be missed.”

“Mark represented the very best of Northwestern chemistry: brilliance without arrogance, achievement without self-importance and collegiality of the most generous kind,” said Mercouri Kanatzidis, a Charles E. and Emma H. Morrison Professor of Chemistry. “He was a giant of chemistry yet one of the sweetest human beings I’ve ever known. His presence made the department better, kinder and intellectually richer.”

A cherished colleague

Outside of work, Ratner loved spending time outdoors, enjoying the crisp breath of nature and fly fishing in sparkling rivers. Colleagues remember his unlimited optimism and how he delighted in small surprises and corny jokes. He brought the same curiosity to life that he brought to the lab, finding glee in unexpected moments and ordinary, sometimes mundane pleasures. His eyes often twinkled, bemused by the everyday idiosyncrasies of life. Inspired by this genuine interest in a wide range subjects, Ratner’s students and colleagues established the Mark A. Ratner Series of Scholars, an annual event that hosts scholars from fields outside of chemistry.

“I had the privilege of having an office adjacent to Mark for many years,” said Brian Hoffman, a Charles E. and Emma H. Morrison Professor of Chemistry. “My science and life were greatly enriched by our routine ‘back-and-forths’ from office to office, sharing insights and attacking puzzlements.”

Ratner’s love for the natural world was accompanied by a quiet dedication to preserving it. He cared deeply about the environment and devoted time and energy to protecting the landscapes and ecosystems he cherished. During his 2015 speech at Weinberg’s convocation, Ratner spoke of ISEN’s mission to develop new sustainable and energy-efficient technologies to help save the environment — a mission close to his heart.

“The most important place where technology meets society is the air we breathe and the water we drink,” he said. “It’s what we see when we wake up in the morning and the stars we look at at night. It’s the kind of life we’d like our children to have.”

Ratner is survived by his wife Nancy, his children and grandchildren. Details about a memorial celebration will be announced at a later date.