A Series of Alkaline Earth Metal Ions Doped Cobalt(II) Heterometallic Cluster Complexes with N‐(phosphonomethyl) Iminodiacetic Acid and 1,3,5‐Benzenetricarboxylate Acid as Co‐ligands

Three alkaline earth metal ions doped Co II heterometallic cluster complexes and one monometallic magnesium cluster complex based on N‐(phosphonomethyl)imino‐diacetic acid (H 4 PMIDA) and 1,3,5‐benzenetricarboxylate acid (H 3 BTC) multifunctional ligands, [Co 13 Mg 2 (PMIDA) 6 (BTC) 2 (H 2 O) 12 ] · 6H 2 O ( 1 ), [Co 13 Ca 2 (PMIDA) 6 (BTC) 2 (H 2 O) 12 ] · 6H 2 O ( 2 ), [CoBa(PMIDA)(H 2 O) 2 ] · H 2 O ( 3 ), and [Mg 15 (PMIDA) 6 (BTC) 2 (H 2 O) 12 ] · 6H 2 O ( 4 ) were synthesized under hydrothermal conditions and characterized by elemental analyses, IR spectroscopy, thermal analyses, and single‐crystal X‐ray diffraction. Compounds 1 , 2 , and 4 are basically isostructural and feature a cubic 3D open framework constructed by [ M 15 (PMIDA) 6 (H 2 O) 12 ] ( M = Co 13 Mg 2 for 1 , Co 13 Ca 2 for 2 , and Mg 15 for 4 ) clusters and BTC 3– ligands. Compound 3 is characterized as a 3D framework containing rings with two tropisms along [010] and [101] directions, which are constructed by BaO 6 chains and CoNO 4 chains. Moreover, solid‐state fluorescent properties of these complexes were also investigated at room temperature, in which compound 4 exhibits the very strong emission band at 411 nm, and might serve as a candidate for hybrid inorganic‐organic fluorescent material.