Described are dialkyne compounds of the formula I
##STR1##
in which n, m, R.sup.1, R.sup.2, X.sup.1, X.sup.2, X.sup.3, X.sup.4,
Z.sup.1, Z.sup.2, A.sup.1, A.sup.2, Q, Y.sup.1 and Y.sup.2 are as defined
herein and the use of such compounds in liquid-crystal media.
Sono descritti i residui del dialkyne del ## del ## STR1 di formula I in cui la n, la m., R.sup.1, R.sup.2, X.sup.1, X.sup.2, X.sup.3, X.sup.4, Z.sup.1, Z.sup.2, A.sup.1, A.sup.2, la Q, Y.sup.1 e Y.sup.2 sono come definiti qui e l'uso di tali residui nei mezzi a cristalli liquidi.
