New Pt...H-N bonding modes in two cycloplatinated complexes, [Pt(C6H4CH2NMe2-2-C,N) (C6H4CH2NMe2H-2-C,H)Br] (1) and [Pt(1-C10H6NMe2-8-C,N)(1-C10H6NMe2H-8-C,H)Br] (2), were characterized by N-15-filtered and 2D NOESY H-1 measurements. Both 1 and 2 show markedly different interactions of an RNMe2H+ group with a platinum centre; the 1J(N-15,H-1) values of 69 and 59 Hz for 1 and 2, respectively, are considerably less than those of the related free and protonated organic amine systems. The corresponding 1J(Pt-195,H-1) values are 72 and 180 Hz, respectively. An approach both to understanding and recognizing these Pt...H-N interactions is presented.