Key points are not available for this paper at this time.
The *NH x intermediates on M n @C 2 N are highly stable for n = 3 and unstable for n = 1, rendering M n @C 2 N as the optimal candidate for driving the eNRR owing to its moderate binding with NH x ( x = 0, 1, 2, 3).
Zhang et al. (Sat,) studied this question.