Reactions of CH₂(NMe₂)₂, (1), SiMe₂(NMe₂)₂, (2), [Ti(cp)(NMe₂)₃](cp =η-cyclopentadienyl), (3), and [Zr(cp)₂(NMe₂)₂], (4), with covalent metal halides MCl₄(M = Ti, Zr, Hf, Si, Ge, or Sn) and MCl₃(M = Ti, V, or Cr) fall into two categories: (a)N-donor chelation leading to complex formation and (b) halide–NMe₂ exchange. Compound (1) gives 1 : 1 complexes with MCl₄(M = Ti or Sn) and a 2 : 1 complex with VCl₃. Compound (2) provides 1 : 1 complexes with MCl₄(M = Ti, Zr, Hf, or Sn). The decomposition of TiCl₄·SiMe₂(NMe₂)₂→[TiCl₃(NMe₂)] invariably occurs in both the solid state and solution. There is no reaction of (2) with metal(III) chlorides. With MCl₄(M = Si or Ge)‘scrambling’ reactions involving halide–NMe₂ exchange occur and these have been monitored by ¹H n.m.r. spectroscopy. Reactions of (3) and (4) with MCl₄(M = Si, Ge, Sn, Ti, Zr, or Hf) consistently feature halide–NMe₂ exchange rather than adduct formation. All complexes have been characterised by analytical and spectroscopic (¹H n.m.r. and i.r.) investigations.