Abstract: Molecular precursor chromium compounds and chromium on silica catalyst precursors suitable for sure in producing chromium on silica catalysts are disclosed. The molecular precursor compounds can be chromium(II) and/or chromium(III) and/or chromium (IV) compounds wherein all ligands are easily removable, in particular ligands selected from the group consisting of anionic ligands of the type —O—CR3R4—CH—R1—R2 or —O—Si—(O—CR3R4—CH—R1R2)3 wherein R1, R2, R3 and R4 may be the same or different and may be any group that does not affect decomposition of the ligand via elimination of beta-hydrogen from —CR3R4—CH—R1R2, amide anionic ligands of the type —N—Si—R5R6R7 and/or —N—C—R5R6R7, wherein R5, R6 and R7 can be the same or different and are preferably selected from hydrogen, methyl groups, ethyl groups, n-propyl groups, iso-propyl groups, tert-butyl groups or aromatic groups; as well as coordinating solvents.