A compound C for radio metal complexation comprising a chelator and one or more biological targeting vectors TV conjugated to said chelator, wherein - the chelator has structure based on 1,4-diazepine with groups R 1, R 2, R 3, R 4, X 1, X 2, X 3; - X 1 and X 2 are OH; - X 3 is OH; - R 1, R 2 are CH 2 -CO; - R 3 is CH 2 -CO; - R 4 is CH 3, CH(CH 3) 2, C(CH 3) 3, (C 6 H 5), (C 5 H 4 N), (C 4 H 5 NHO) or (C (5-k) H (5-k) N k); wherein - (C 6 H 5) designates a phenyl ring; - (C (5-k) H (5-k) N k) with k = 1, 2, 3 or 4 designates a pyrrole, imidazole, triazole or tetrazole residue; - (C 4 H 5 NHO) designates a pyrrolidone residue; - (C 5 H 4 N) designates pyridine residue; - the one or more targeting vectors TV are conjugated at R 4, via optional linker/spacer groups LS, whereby one or more hydrogen atoms of R 4, are substituted; and - the one or more targeting vectors TV independently of one another are selected from the group comprising amino acid residues; residues of amino acid derivatives, such as L-tyrosine, L-serine, L-lysine and Alpha-methyl-L-tyrosine; residues of peptides, such as bombesins and melanocortins; residues of Octreotide; residues of proteins; residues of micro proteins; antibodies, such as huKS (humanized antibody for EpCAM respectively KSA) and hul4.18 (humanized antibody for disialoganglioside GD2); recombinant antibodies; antibody fragments; bisphosphonates; sugars; glucose; fructose; sucrose; glutamine; glucosamine; lipids; nucleotides; nucleosides; DNA-components; hypoxia tracers, such as 2-nitroimidazole; azomycine (2-nitroimidazole-arabinoside); erythronitroimidazole; ethyltyrosine; 2-(2-nitro- H-imidazole-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)-acetamide; liposomes; polymers and nanoparticles. - the chelator has structure based on 1,4-diazepine with groups R 1, R 2, R 3, R 4, X 1, X 2, X 3; - X 1 and X 2 are OH; - X 3 is OH; - R 1, R 2 are CH 2 -CO; - R 3 is CH 2 -CO; - R 4 is CH 3, CH(CH 3) 2, C(CH 3) 3, (C 6 H 5), (C 5 H 4 N), (C 4 H 5 NHO) or (C (5-k) H (5-k) N k); wherein - (C 6 H 5) designates a phenyl ring; - (C (5-k) H (5-k) N k) with k = 1, 2, 3 or 4 designates a pyrrole, imidazole, triazole or tetrazole residue; - (C 4 H 5 NHO) designates a pyrrolidone residue; - (C 5 H 4 N) designates pyridine residue; - (C 6 H 5) designates a phenyl ring; - (C (5-k) H (5-k) N k) with k = 1, 2, 3 or 4 designates a pyrrole, imidazole, triazole or tetrazole residue; - (C 4 H 5 NHO) designates a pyrrolidone residue; - (C 5 H 4 N) designates pyridine residue; - the one or more targeting vectors TV are conjugated at R 4, via optional linker/spacer groups LS, whereby one or more hydrogen atoms of R 4, are substituted; and - the one or more targeting vectors TV independently of one another are selected from the group comprising amino acid residues; residues of amino acid derivatives, such as L-tyrosine, L-serine, L-lysine and Alpha-methyl-L-tyrosine; residues of peptides, such as bombesins and melanocortins; residues of Octreotide; residues of proteins; residues of micro proteins; antibodies, such as huKS (humanized antibody for EpCAM respectively KSA) and hul4.18 (humanized antibody for disialoganglioside GD2); recombinant antibodies; antibody fragments; bisphosphonates; sugars; glucose; fructose; sucrose; glutamine; glucosamine; lipids; nucleotides; nucleosides; DNA-components; hypoxia tracers, such as 2-nitroimidazole; azomycine (2-nitroimidazole-arabinoside); erythronitroimidazole; ethyltyrosine; 2-(2-nitro- H-imidazole-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)-acetamide; liposomes; polymers and nanoparticles.