The TIP31 (NPN) is a poor choice, as it needs 20-40mA base current from the 3.3volt pin for 1Amp. A logic level (SMD) mosfet could do better there. With a 5volt supply, you could have two IR LEDs in series, for double the power.
What are you using this for (modulation type). 1Amp LED current is a lot. Most common remotes top at 200mA peak. For that you can use a 2N2222. With 200mA peak you can bridge a 50m beambreak sensor.
Leo..