Miserable escape string problem

Using this string: "{$var1: $var2}" ....of course it doesn't work as some might expect. But why in the name of [whatever, too many to list] doesn't this one below work? "\{$var1: $var2}" If \ is an escape character why does it also appear in the string output? Why does the above \ escape {$var1 and not only the {? Miserable.