Key binding "Cmd+<" not recognised on Mac

Hi !
I’m trying to create a keyboard shortcut in the atom-text-editor using the shortcut cmd+<. Here is the code, resp. in keymap.cson and init.coffee:

'atom-text-editor':
  'cmd-<': 'custom:insert-backslash'

atom.commands.add 'atom-text-editor',
  'custom:insert-backslash': ->
    atom.workspace.getActiveTextEditor()?.insertText('\\')

However this doesn’t work. Actually, the problem already occurs in the Key Binding Resolver: cmd+< is not recognised, although both cmd and < are recognised separately. Also, < is recognised as @, while @ is recognised as < (only in the Key Binding Resolver, not in the editor). Putting cmd+@ instead of cmd+< in the code works, although of course this is not the keybinding I want.

Does anybody have a clue? Thanks in advance for your help.

Note: I have a MacBook Pro with AZERTY keyboard, so that ‘@’ is on the left of the ‘1’ key and ‘<’ is on the left of the ‘w’ key.

Context: I’m typesetting in LaTeX, and I would like a similar keybinding for the backslash to the one with Windows keyboard, that is similar to AltGr+<.