Single crystal X-ray structural characterizations are recorded for a wide range of adducts of the form MX:dppx (1:1)((n)), M = silver(I) (predominantly), copper(I), X = simple (pseudo-) halide or oxy-anion (the latter spanning, where accessible, perchlorate, nitrate, carboxylate - a range of increasing basicity), dppx=bis(diphenylphosphino)alkane, Ph2P(CH2)(x)PPh2, x = 3-6. Adducts are defined of two binuclear forms: (i) [LM(mu-X)(2)L], with each ligand chelating a single metal atom, and (ii) [M(mu-X)(2)(mu-(P-L-P'))(2)M'] where both ligands L and halides bridge the two metal atoms; a few adducts Lire defined as polymers, the ligands connecting M(p-X)2M' kernels, this motif persisting in all forms. Synthetic procedures for all adducts have been reported. All compounds have been characterized both in solution (H-1, C-13, P-31 NMR, ESI MS) and in the solid state (IR). (C) 2004 Elsevier B.V. All rights reserved.