director of research vs research director

director of research and research director both are nouns.

Word	Noun	Adjective	Verb	Adverb
director of research	Yes	No	No	No
research director	Yes	No	No	No

As nouns, director of research and research director are synonyms defined as:

director of research and research director: a supervisor in a research center

director of research (noun)	research director (noun)
a supervisor in a research center	a supervisor in a research center