A range of dialky α-hydroxyiminophosphonates R′C[double bond, length half m-dash]N(OH)P(O)(OR)2, with substituents of varying bulk (R = Et, R′ = Me L1, Et L2, cPr L3, 3-heptyl L4; R = iPr, R′ = Et L5, 3-heptyl L6; R = nBu, R′ = Pr L7) have been used to synthesise neutral metal complexes with nickel(II) [Ni(L1–3,5)Cl2], cobalt(II) [Co(L1–3,5)Cl2] and lanthanides (LaIII with L1,2,5, PrIII with L1,2,4–7, NdIII with L5, GdIII with L2,5 and DyIII with L2,5) the charge being balanced by anionic ligands chloride or nitrate. Included in this range are two 3-heptyl derivatives which have not previously been reported. All the metal complexes have been fully characterised by elemental analysis, IR, electronic and NMR spectroscopy and mass spectrometry. X-Ray crystallography has been used to establish the structure of six key metal complexes and one of the free ligands (L3). Three different bonding modes have been established. The d-block metal chlorides consistently show symmetrical bidentate coordination in [ML2Cl2], the lanthanide chlorides [ML3Cl3] are all asymmetrically bidentate and monodentate coordination was observed in the neodymium nitrate complex [NdL52(NO3)3(H2O)].