Structural, thermal and topological characterization of coordination networks containing flexible aminocarboxylate ligands with a central biphenylene scaffold. Issue 42 (9th October 2019)

• Record Type: Journal Article
• Authors: Balestri, Davide; Scilabra, Patrick; Carraro, Claudia; Delledonne, Andrea; Bacchi, Alessia; Mazzeo, Paolo Pio; Carlucci, Lucia; Pelagatti, Paolo
• Is Part Of: CrystEngComm. Volume 21:Issue 42(2019)
• Page Start: 6365
• Page End: 6373
• Publication Date: 2019-10-09
• Subjects: Crystals -- Periodicals; Crystal growth -- Periodicals; Crystallography -- Periodicals; Cristaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Cristallographie -- Périodiques; 548
• DOI: 10.1039/c9ce01230c
• Languages: English
• ISSNs: 1466-8033

Abstract

Abstract : Flexible aminocarboxylate ligands have been used to construct coordination networks containing Zr, Zn and Cd featured by different dimensionalities and topologies. Abstract : Herein, four different coordination networks were isolated and structurally characterized by combining two aminocarboxylate ligands, 4, 4′-[biphenyl-4, 4′-diylbis(azanediyl)]dibenzoic acid and 5, 5′-[biphenyl-4, 4′-diylbis(azanediyl)]diisophthalic acid (H2 L1 and H4 L2, respectively), with different transition metals (Zn(ii ), Zr(iv ) and Cd(ii )) under solvothermal conditions. The reaction between H2 L1 and Zn(NO3 )2 ·6H2 O led to two different coordination networks. In PUM flex 1-Zn, which has the formula {[Zn4 O(L1)3 (DMF)2 ](DMF)5 } n ·(DMF) x, the ligand always displays a syn conformation (with respect to the central biphenylene scaffold), whereas in the polymorph PUM flex 1.1-Zn, one of the three ligands composing the asymmetric unit adopts an anti conformation. Although the two supramolecular isomers have equivalent stoichiometry and dimensionality, they show different topologies and entanglement types: parallel polycatenation of the 6 3 -hcb and 2-fold interpenetration of the 4 4 -sql layers, respectively. In the case of PUM flex 1-Zr, with the formula {[Zr6 O4 (OH)8 (L1)4 (H2 O)2 ] n ·(DMF) x, H2 L1 exclusively adopts the syn conformation, forming 1D-chains of rugby-ball shaped aggregates (topological type 2, 8C1) interconnected through H-bonds with water molecules. In contrast, H4 L2 behaves as a dianionic ligand in PUM flex 2-Cd, with the formula [Cd(κ 2 -COO)2 (DMF)3 (DMF)] n, forming 1D zig-zag chains connected through the N–H⋯OC(OH) H-bonds to provide planar layers of sql topology. In all cases, the ability of the amine functions to interact with the H-bond active guests is structurally highlighted by the recurrent N–H⋯ODMF interaction modelled in the X-ray structures.