Influence of the steric properties of pyridine ligands on the structure of complexes containing the {LnCd2(bzo)7} fragment

The reaction of Cd(NO 3 ) 2 · 4H 2 O and Eu(NO 3 ) 3 · 6H 2 O or Tb(NO 3 ) 3 · 6H 2 O with potassium 3,5-di- tert -butylbenzoate (Kbzo) and N -donor ligands (1,10-phenanthroline (phen), 2,4-lutidine (2,4-lut), 3,4-lutidine (3,4-lut), phenanthridine (phtd), 2,3-cyclododecenopyridine (cdpy), acridine (acr)) afforded heterometallic LnCd 2 complexes: [EuCd 2 (bzo) 7 (EtOH) 2 (phen)] (2) , [LnCd 2 (bzo) 7 (2,4-lut) 4 ] (Ln = Eu (3) , Tb (4)) , [EuCd 2 (bzo) 7 (H 2 O) 2 (2,4-lut) 2 ] · MeCN (5) , [EuCd 2 (NO 3 )(bzo) 6 (EtOH) 2 (2,4-lut) 2 ] (6) , [EuCd 2 (bzo) 7 (H 2 O)(EtOH)(3,4-lut) 2 ] · 5EtOH (7) , 3[EuCd 2 (bzo) 7 (H 2 O) 2 (phtd) 2 ] · 4phtd (8) , [EuCd 2 (bzo) 7 (EtOH) 3 (cdpy)] (9) , 2[EuCd 2 -(bzo) 2 (EtOH) 4 ] · acr (10). The structures of complexes 2, 3 , and 5–10 were determined by single-crystal X-ray diffraction. The isostructurality of complexes 3 and 4 was confirmed by powder X-ray diffraction. T he structure of the trinuclear {Ln 2 Cd} metal core is stable and independent of the type of peripheral ligands coordinated to cadmium atoms. Photoluminescent properties of compounds 3 and 4 were studied.