Structural Diversity of Four Metal–Organic Frameworks Based on Linear Homo/Heterotrinuclear Nodes with Furan-2,5-dicarboxylic Acid: Crystal Structures and Luminescent and Magnetic Properties

Four new homo- and heterometallic metal–organic frameworks (MOFs) based on linear homo/heterotrinuclear nodes, namely, {[NH 2 (CH 3 ) 2 ] 2 [Co 3 (FDA) 4 (CH 3 OH) 2 ]} n ( 1 ), {[NH 2 (CH 3 ) 2 ] 2 [Co 3 (FDA) 4 ]·2DMF} n ( 2 ), {[Gd 2 Co(FDA) 4 (H 2 O) 4 ]·2H 2 O} n ( 3 ), and {[Dy 2 Co(FDA) 4 (glycol) 2 ]·2H 2 O} n ( 4 ) (H 2 FDA = furan-2,5-dicarboxylic acid), were obtained under solvothermal conditions and characterized by single crystal X-ray diffraction, magnetic susceptibility, and luminescence measurements. The building blocks of four MOFs are linear trinuclear clusters stabilized by carboxylic groups, but the three-dimensional frameworks are different. MOFs 1 and 2 are both pcu nets with a point symbol of (4 12 .6 3 ), whereas MOFs 3 and 4 exhibit 3,10T9 and tfz-d nets with the point symbols of (4 18 .6 24 .8 3 )(4 3 ) 2 and (4 3 ) 2 (4 6 .6 18 .8 4 ), respectively. Magnetic susceptibility measurements indicate that there are antiferromagnetic interactions in 1 – 3, while 4 displays interesting ferromagnetic interactions between Co(II) and Dy(III) ions. Luminescence investigation of 4 shows intense and characteristic emission bands of Dy(III) ions in the solid state.