Your files have ISO88591 charset names (one byte per accentuated characters instead of 2), then they don’t fit the default charset which is UTF-8 nowadays.
To make ls not to escape these characters, you could type LANG=fr_FR.iso88591 (replace fr and FR by your language code, probably PT), then ls will not escape the accentuated ISO88591 characters. The available values are listed with localedef --list-archive. If none of the values are iso88591, you may need to add them with dpkg-reconfigure locales (Debian based system only).
But if you use a UTF8 terminal, characters won’t be printed normally… you should also use an iso88591 terminal.
An alternative to an iso88591 terminal is to type ls|iconv -f iso88591 -t utf-8 (Less practical).
Could you print us the $LANG value before changing its value (this will give the national code you should use instead of fr. Or type locale which is more complete). The localedef --list-archive output can be useful too. (Your environment also : KDE, Gnome…)
Note : if you plan to use these files in a UTF-8 environnement, you may need to rename them and avoid switching to an ISO88951 mode.
localeoutput?