NOVELTY - Metal complex compounds (I)-(III) are new.    USE - (I)-(III) are useful as emitting compounds in at least one emitting layer of electronic devices, preferably organic electroluminescent devices (preferred), organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, light-emitting electrochemical cells and organic laser diodes; as a catalyst; or for generating singlet oxygen (all claimed).    ADVANTAGE - The organic electroluminescent device comprising (I), exhibits good service life, good efficiency.    DETAILED DESCRIPTION - Metal complex compounds of formula (I)-(III) are new.    M = Cu, Ag or Au;    E = Si, Ge or Sn;    L1 = coordinating group which is covalently bonded to E through single bond or bridging group, where 2 L1 which are bonded to same metal atom, are bonded with each other through single bond or bridging unit; either    L2 = monodentate ligand which coordinates to M, where L2 is bonded to L1 through single bond or bridging unit; or    2 L2 which coordinate to same metal = bidentate ligand; either    R = 1-20C alkyl or 1-20C (thio)alkoxy (both linear) or 3-20C alkyl or 3-20C (thio)alkoxy (both branched or cyclic), 2-20C alkenyl or 2-20C alkynyl (in all groups at least one non-adjacent CH2 group is optionally replaced by R1C=CR1, CC, Si(R1)2, C=O, NR1, O, S or CONR1, and at least one H is optionally replaced by D, F, Cl, Br, I or CN), (hetero)aromatic ring with 5-60 aromatic ring atoms, (hetero)aryloxy with 5-40 aromatic ring atoms, (hetero)aralkyl with 5-40 aromatic ring atoms, diarylamino with 10-40 aromatic ring atoms, diheteroarylamino with 10-40 aromatic ring atoms or arylheteroarylamino with 10-40 aromatic ring atoms (all optionally substituted by at least one group R1), H, D, F, Cl, Br, I, N(R1)2, CN, NO2, OH, COOH, C(=O)N(R1)2, Si(R1)3, B(OR1)2, C(=O)R1, P(=O)(R1)2, S(=O)R1, S(=O)2R1 or OSO2R1, where one R may be additionally coordinated to the metal; or    R+R = mono- or polycyclic and aromatic or aliphatic ring; either    R1 = 1-20C alkyl or 1-20C (thio)alkoxy (both linear) or 3-20C alkyl or 3-20C (thio)alkoxy (both branched or cyclic), 2-20C alkenyl or 2-20C alkynyl (in all groups at least one non-adjacent CH2 group is optionally replaced by R2C=CR2, CC, Si(R2)2, C=O, NR2, O, S or CONR2, and at least one H is optionally replaced by D, F, Cl, Br, I, CN or NO2), (hetero)aromatic ring with 5-60 aromatic ring atoms, (hetero)aryloxy with 5-40 aromatic ring atoms, (hetero)aralkyl with 5-40 aromatic ring atoms, diarylamino with 10-40 aromatic ring atoms, diheteroarylamino with 10-40 aromatic ring atoms or arylheteroarylamino with 10-40 aromatic ring atoms (all optionally substituted by at least one group R2), H, D, F, Cl, Br, I, N(R2)2, P(R2)2, CN, NO2, Si(R2)3, B(OR2)2, C(=O)R2, P(=O)(R2)2, S(=O)R2, S(=O)2R2 or OSO2R2; or    at least 2 adjacent R1 = mono- or polycyclic and aromatic or aliphatic ring; either    R2 = aliphatic and/or (hetero)aromatic 1-20C hydrocarbyl (in which at least one H is optionally replaced by F), H, D or F; or    at least 2 R2 = mono- or polycyclic and aromatic or aliphatic ring;    G = single bond through which L1 is bonded to E or bridging unit through which L1 is bound to E;    n, m = 1-3;    s = 1 or 2;    p = 3-n; and    q = 2-n.    Provided that when L2 is bonded to L1 through single bond or bridging unit, then L2 is not independent ligand, but a coordinating group. INDEPENDENT CLAIMS are also included for:    (1) preparing (I); and    (2) a formulation, preferably a solution or dispersion comprising (I)-(III) and at least one further compound, preferably a solvent.