Essentially like the others, but maybe slightly simpler:

>perl -wMstrict -le
"my $s = '{key_1 : value_1}{key_2 : value of 2} {key n : 0}';
 my $spl = qr{ \s* [{}:] \s* }xms;
 my %hash = grep length($_), split $spl, $s;
 use Data::Dumper;
 print Dumper \%hash;
"
$VAR1 = {
          'key_1' => 'value_1',
          'key_2' => 'value of 2',
          'key n' => '0'
        };
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The grep is needed to filter out spurious zero-length sub-strings produced by the split regex, so you can't have a key or value that is a zero-length string. Note that embedded spaces are preserved within key and value sub-strings, but leading and trailing spaces are stripped.