Combine 1 1/4 cups water and sugar in a microwave-safe bowl; microwave at HIGH for 3 minutes or until boiling. Stir until sugar dissolves. Stir in rind. Cool completely.
Strain mixture through a sieve into a bowl; discard rind. Stir in juice and liqueur. Divide mixture among 6 (4-ounce) ice-pop molds. Top with lid; insert craft sticks. Freeze 4 hours or until thoroughly frozen.