NOVELTY - Composition comprises a metal amidoborane and an amine.    USE - The composition is useful for generating hydrogen (claimed); and for low-temperature proton exchange membrane (PEM) fuel cells.    ADVANTAGE - The invention provides efficient, safe, and cost-effective processes for preparation of metal amidoboranes compositions of high purity and high hydrogen content.    DETAILED DESCRIPTION - Composition comprises a metal amidoborane comprising M(NH2BH3)x and an amine comprising NR1R2R3.    M=a metal selected from an alkali metal, an alkaline earth metal, and a transition metal;    R1, R2, and R3=independently selected from hydrogen, hydrocarbyl, substituted hydrocarbyl, and silyl, provided that any two of R1, R2, and R3 together may form a ring or a ring system selected from carbocyclic, heterocyclic, aryl, and heteroaryl; and    x=an integer equal to the valence of M.    INDEPENDENT CLAIMS are:    (1) a process for preparing a compound comprising M(NH2BH3)x comprising contacting ammonia borane with a compound comprising M(NR4R5)x in the presence of an amine solvent comprising NR1R2R3 to form the compound comprising M(NH2BH3)x;    (2) a composition comprising a metal amidoborane comprising M(NH2BH3)x and an amine comprising NR1R2R3, where the composition is prepared by a process comprising: (a) contacting ammonia borane with a metal amide comprising M(NR4R5)x in the presence of an amine solvent comprising NR1R2R3 to form the composition and an amine by-product comprising HNR4R5; and (b) isolating the composition by partially removing the amine solvent and/or the amine by-product; and    (3) a method for generating hydrogen comprising heating a composition comprising a metal amidoborane comprising M(NH2BH3)x and an amine comprising NR1R2R3 such that hydrogen is released.    M=a metal selected from an alkali metal, an alkaline earth metal, and a transition metal;    R1, R2, R3, R4, and R5=are independently selected from hydrogen, hydrocarbyl, substituted hydrocarbyl, and silyl, provided any two of R1, R2, and R3 together may form a ring or a ring system chosen from carbocyclic, heterocyclic, aryl, and heteroaryl, and R4 and R5 together may form a ring or a ring system selected from carbocyclic, heterocyclic, aryl, and heteroaryl; and    x=an integer equal to the valence of M.