Execution of
user@EWD-MacBook-Pro:~$ export property.name=property.value
Gives me
-bash: export: `property.name=property.value\
As others have said, bash doesn't allow it so you'll have to use your favourite scripting language to do it. For example, in Perl:
perl -e '$ENV{"property.name"} = "property.value"; system "bash"'
This will fire up a subshell bash with the property.name
environment variable set, but you still can't access that environment variable from bash (although your program will be able to see it).
Edit: @MarkEdgar commented that the env command will work too:
env 'property.name=property.value' bash # start a subshell, or
env 'property.name=property.value' command arg1 arg2 ... # Run your command
As usual, you only require quotes if you need to protect special characters from the shell or want to include spaces in the property name or value.