[K(Q)] [{ReH2(PMePh2)(2)}(2)(mu -H)(3)] is prepared by treatment of {ReH2(PMePh2)(2)}(2)(mu -H)(4) with potassium hydride and a crown ether (Q = 18-crown-6 or 1,10-diaza-18-crown-6). The [K(1,10 diaza-18-crown-6)](+) salt contains NH . . . HRe protonic-hydridic bonds and has been characterized by P-31 NMR, variable temperature H-1 NMR, IR, and X-ray crystallography. The pK(alpha)(THF) = 33 of {ReH2(PMePh2)(2)}(2)(mu -H)(4) was determined on the basis of its reaction with [K(2,2,2-crypt)][PO(OEt)(2)NPh]. [GRAPHICS]