Forced Tie between non-equal notes?

[Nils]

Hello list,

for some reasons, mostly educational and theoretic, I want to create a tie 
between two different notes: enharmonic siblings. Between dis and ees for 
example. This seems to be not possible with a default Lilypond Tie (which is a 
very good setting!). Is there a way to force a tie to the next note or at least 
get the graphics without creating an svg curve through coordinates?

Nils