A process for preparing metal compounds of the general formula, or with at least one ligand containing at least one nitrogen and bonded via at least one oxygen or sulfur atom [(L 1) n1 (L 2) n2 (L 3) n3 (L 4) n4] [(L 1) n1 (L 2) n2 (L 3) n3] 2 O [(L 1) n1 (L 2) n2] n in which M = Sn, Ti, Zr or Hf, n1, n2, n3, n4 are each 0 or 1 and n is greater than or equal to 2, L 1, L 2, L 3, L 4 are each mono-, di-, tri- or tetravalent ligands, where at least one ligand per M is defined as follows: -X-Y in which X = O, S, OC, OC, O S, O S Y = -R 1 -N(R 2)(R 3) or -R 1 -C(R 4)=NR 2, in which R 1, R 2, R 3 and R 4 are each independently saturated or unsaturated, cyclic or acyclic, branched or unbranched, substituted or unsubstituted hydrocarbyl radicals optionally interrupted by heteroatoms, or R 2, R 3, R 4 are each independently hydrogen, R 1 -X, or R 3 or R 2 and R 1 or R 3 and R 1 or R 4 and R 1 or R 4 and R 2 form a ring, where the remaining ligands are each independently -X-Y as defined above or are defined as follows: saturated or unsaturated, cyclic or acyclic, branched or unbranched, substituted or unsubstituted hydrocarbyl radicals optionally interrupted by heteroatoms, or halides, hydroxides, amide radicals, oxygen, sulfur, R 2 or XR 2, comprising the steps of (a) providing a compound of the formula ML 4 where L is independently R, OR or Hal, where: R = C 1 to C 8 -alkyl, Hal = Cl, Br or I and M = Sn, Ti, Zr or Hf, and (b) reacting the compound provided in process step (a) with at least one compound of the formula H-X-Y and/or M 1 -X-Y, where X and Y are each as defined above and M 1 = Li, Na, K, Ca, Mg or NH 4 +, characterized in that the reaction in process step (b) is performed in the presence of one or more compounds selected from NH 3, primary, secondary and tertiary amines, M 2 OH and M 2 O-R 5, where R 5 is a hydrocarbyl radical having 1 to 6 carbon atoms and M 2 is Li +, Na +, K +, Ca 2+ or Mg 2+. M = Sn, Ti, Zr or Hf, n1, n2, n3, n4 are each 0 or 1 and n is greater than or equal to 2, L 1, L 2, L 3, L 4 are each mono-, di-, tri- or tetravalent ligands, where at least one ligand per M is defined as follows: -X-Y in which X = O, S, OC, OC, O S, O S Y = -R 1 -N(R 2)(R 3) or -R 1 -C(R 4)=NR 2, in which R 1, R 2, R 3 and R 4 are each independently saturated or unsaturated, cyclic or acyclic, branched or unbranched, substituted or unsubstituted hydrocarbyl radicals optionally interrupted by heteroatoms, or R 2, R 3, R 4 are each independently hydrogen, R 1 -X, or R 3 or R 2 and R 1 or R 3 and R 1 or R 4 and R 1 or R 4 and R 2 form a ring, where the remaining ligands are each independently -X-Y as defined above or are defined as follows: saturated or unsaturated, cyclic or acyclic, branched or unbranched, substituted or unsubstituted hydrocarbyl radicals optionally interrupted by heteroatoms, or halides, hydroxides, amide radicals, oxygen, sulfur, R 2 or XR 2, comprising the steps of (a) providing a compound of the formula ML 4 where L is independently R, OR or Hal, where: R = C 1 to C 8 -alkyl, Hal = Cl, Br or I and M = Sn, Ti, Zr or Hf, and (b) reacting the compound provided in process step (a) with at least one compound of the formula H-X-Y and/or M 1 -X-Y, where X and Y are each as defined above and M 1 = Li, Na, K, Ca, Mg or NH 4 +, (a) providing a compound of the formula ML 4 where L is independently R, OR or Hal, where: R = C 1 to C 8 -alkyl, Hal = Cl, Br or I and M = Sn, Ti, Zr or Hf, and (b) reacting the compound provided in process step (a) with at least one compound of the formula H-X-Y and/or M 1 -X-Y, where X and Y are each as defined above and M 1 = Li, Na, K, Ca, Mg or NH 4 +,