Academician Yusif Heydar Mammadaliyev (1905-1961) was born in the Nakhchivan Autonomous Republic, Ordubad city. In 1926, he graduated from the Higher Pedagogical Institute named after V.Lenin. In 1929, he was admitted to the Chemistry Faculty at Moscow State University and graduated in 1931. He completed his diploma thesis under the supervision of N. Zelinsky, an academician of the USSR Academy of Sciences. In 1942, he defended his doctoral dissertation on the topic "Synthesis of toluene by alkylation and dealkylation of aromatic hydrocarbons". In 1943, he was awarded the title of professor in the specialty "Petrochemistry". He worked as an assistant, associate professor and professor at Azerbaijan State University (ASU) in addition to his scientific research work starting in 1934. In 1943, Mammadaliyev established the department of Petrochemistry (now the department of Petrochemistry and chemical technology) at ASU and headed it until the end of his life. It can be noted with full justification that Y. Mammadaliyev was one of the founders of the Academy of Sciences of the Azerbaijan SSR in 1945. An entire period of the development of chemical science in the Republic is associated with the name of this famous scientist. In 1945, he was elected an academician of the Academy of Sciences of the Azerbaijan, a member of the Presidium and the director of the Oil Institute of the Academy. He was one of the 15 prominent figures who founded the academy and became the first academician of Azerbaijan. In 1951-1954, he was the academic secretary of the Physics, Chemistry and Petroleum department of the Academy of Sciences of the Azerbaijan and in 1954-1958, he was the rector of the Azerbaijan State Univesity named after S.Kirov. His main scientific work was in the field of catalytic processing of oil and oil gases. He also conducted significant work in several areas, including the catalytic aromatization of the gasoline fraction from Baku oil, the production of detergents and organic silicon compounds, the creation of plastic materials from pyrolysis products and the study of the mechanism of action of Naftalan oil. Academician Mammadaliyev made significant studies during the Second World War, inventing high-octane gasoline and the well-known "Molotov cocktail." He authored over 200 scientific works, including six monographs and trained 12 doctors of science and 29 doctors of philosophy. He had participated in international scientific congresses and symposiums held in the USA, France, England, Poland, Mongolia and other countries. One of his notable achievements was developing a method for synthesizing isopropylbenzene by alkylating benzene with propylene. This method was crucial in providing high-octane fuel for soviet aviation during the war. His research in this field received high recognition from the state and in 1944, he was awarded the "Order of Lenin," followed by the "Stalin Prize" in 1946.