Items aren't being deleting in they're item form with custom NBT data

I'm trying to make a special ability system that allows you to throw down a sword that's glowing and it gives you special effects like healing and heart particles, well, I'm trying to delete this item in it's thrown form and it wont delete!
Here is the command:
/kill @e[type=Item,id=267] {Item:{id:minecraft:iron_sword,tag:{ench:[{id:16s,lvl:1s}]}}}
Put that in a command on a hopper clock and enchant an iron sword with sharpness I and toss it on the ground, and you'll see that it doesn't get deleted. If that happens, remove the NBT data a do it again, and it deletes it...