<, and %q{}
are your friends. Info on using them from the Programming Ruby
The Pragmatic Programmer's Guide.
Try mixing the various approaches:
%q{`~!@#$%^&*()_-+}+"{}"+%q{=|[]\\:";'<>?,./}
or alternatively, just use backslashes to escape the problematic chars:
"`~!@\#$%^&*()_-+{}=|[]\\:\";'<>?,./"