Step-by-step assembly of 4d-4f-3d complex based on heptamolybdate anion

► A new 4d-4f-3d complex that containing 1D chain was obtained and discussed. ► New coordination geometry with higher coordination number of heptamolybdate. ► Series of heptamolybdate contained complexes were synthesized and characterized. ► Complexes mentioned above show antiferromagnetic behavior.