Arthur W. Sloan, 79, an organic chemist and former chairman of the Atlantic Research Corp. and then the Susquehanna Corp. in Alexandria, died Tuesday at Georgetown University Hospital. He had Parkinson's disease.

Atlantic Research, which he has helped found in 1949, and Susquehanna merged in 1967. Dr. Sloan, who had been chariman of the board and chief executive office of the former, became chairman of the board and chief executive officer of the latter. He stepped down in 1971.

Over the years, Dr. Sloan, who held numerous patents in his field, had played a major role in the development of solid propellants used in this country's rockets program.

He was born in Denver, Ill. A graduate of the University of Illinois, he earned master's and doctor's degrees from Harvard Univeristy. While at Harvard, he taught at Radcliffe College.

Dr. Sloan worked from 1926 to 1944 as a research chemist at the B. F. Goodrich Co. in Akron, Ohio, where he became director of rubber chemical research.

He then spent two years in Cairo, Egypt, as a chemical requirements officer for the Middle East of the U.S. Foreign Economic Administration. o

After working briefly for the office of Naval Research in New York City, he became director of the chemistry division of Engineering Research Associates in Arlington.

After the founding of Atlantic Research in 1949, Mr. Sloan became its president. He was named chairman in 1951, vice chairman in 1962 and then returned as chairman in 1965 after winning a well-publicized proxy fight for control.

In 1950-51, Dr. Sloan was on assignment with the Joint Chiefs of Staff as a consultant with the weapons systems evaluation group and was sent to Korea.

He was a former official of the Pan American Sulphur Co. He was the author of numerous publications in his field.

He belonged to the American Association for the Advancement of Science, the American Chemical Society, the American Ordnance Association, the Combustion Institute, the Operations Research Society, the American Institute of Aerospace and Astronautics and the Cosmos Club.

He had been active in the Washington Center for Metropolitan Studies, the board of the National Symphony Orchestra Association, of which he was a former first vice president. He had served on the council of the Harvard Graduate Society of Advanced Study and Research.

Dr. Sloan had been a resident of Washington for many years.

His wife, Dr. Ruth Catherine Sloan, an authority on Africa and the Near East, died in 1976.

He is survived by a brother, Robert C., of Hagerstown, Md., and three sisters, Agnes S. Larson and M. Beatrice Simmons, both of Springfield, Ill., and Madelene K. Thompson, of Ekalaka, Mont.