capital of Ireland vs Irish capital

capital of Ireland and Irish capital both are nouns.

Word	Noun	Adjective	Verb	Adverb
capital of Ireland	Yes	No	No	No
Irish capital	Yes	No	No	No

As nouns, capital of Ireland and Irish capital are synonyms defined as:

capital of Ireland and Irish capital: capital and largest city and major port of the Irish Republic

Other synonyms of capital of Ireland include Dublin.

capital of Ireland (noun)	Irish capital (noun)
capital and largest city and major port of the Irish Republic	capital and largest city and major port of the Irish Republic