Nothing was converted into capital (10)
I believe the answer is:
washington
'capital' is the definition.
(Washington is an example)
'nothing was converted' is the wordplay.
'converted' is an anagram indicator.
'nothing'+'was'='nothingwas'
'nothingwas' anagrammed gives 'WASHINGTON'.
'into' acts as a link.
(Other definitions for washington that I've seen before include "Old president" , "Irving" , "American general and president" , "Seattle's state" , "United States capital" .)