QR 3733 then IB 5424 at Barcelona
Mahón → Barcelona → London Heathrow
Timetable, Barcelona time
19:25QR 3733 from Mahón at the gate
18:45IB 5424 to London Heathrow leaves the gatealso LL 5424, VY 7642, BA 8084
23 h 20 apart on the timetable, overnight
IB 5424 leaves 23 h 20 after QR 3733 arrives on the timetable: more than half a day, so not a connection we count.