“…Considerable progress in the exploration of the fundamental chemistry of lanthanides was achieved in recent years [ 57 , 58 , 59 , 60 ], and specific properties of their compounds make them interesting for applications particularly in fields such as catalysis [ 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ], optical [ 71 , 72 , 73 , 74 ] and magnetic materials [ 75 , 76 , 77 ], but also in pharmacy and life science [ 78 , 79 , 80 , 81 ]. Although the present series of compounds would give a unique opportunity for a comprehensive comparative study, it cannot be the aim of the present, introducing paper to cover all these interesting issues of lanthanide chemistry.…”