Three transition metal complexes with 3,5-bis((4′-carboxylbenzyl)oxy)benzoic acid and 4′-(4-pyridyl)-2,2′:6′,2″-terpyridine: Syntheses, structures and properties

ABSTRACT

Three transition metal complexes, [Cu(PYTPY)₂]·Hbcb·2H₂O (1), [Ni(PYTPY)₂]·Hbcb·2H₂O (2) and [Cd(H₂bcb)₂(PYTPY)] (3) [where, H₃bcb = 3,5-bis((4’-carboxylbenzyl)oxy)benzoic acid, PYTPY = 4′-(4-pyridyl)-2,2′:6′,2″-terpyridine], were synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. Single-crystal X-ray diffraction analyses reveal that the complexes 1 and 2 crystallize in the same monoclinic P2(1)/n space group with similar cell parameters. In complexes 1 or 2, an asymmetric unit contains one Cu²⁺/Ni²⁺ ion, two PYTPY ligands, one free Hbcb²⁻ ligand and two free water molecules. The metal center is six-coordinate via six nitrogen atoms derived from two different PYTPY ligands in a distorted octahedral coordination geometry. The isostructural complexes 1 and 2 exhibit two dimensional supramolecular layer structures based on c-π stacking interactions and hydrogen bonds. And the complex 3 crystallize in the triclinic P-1 space group. The discrete unit of 3 consists of one Cd²⁺ ion, two H₂bcb⁻ and one PYTPY molecule. Each Cd²⁺ ion is six-coordinated by three carboxylate oxygen atoms from two different H₂bcb⁻ ligands, and three nitrogen atoms from one PYTPY molecule. Zero dimensional structure of 3 is also further extended by π-π interactions and hydrogen bonds to form three dimensional supramolecular network. Furthermore, the complexes 1 and 2 exhibit relevant magnetic properties, and the complex 3 exhibit photoluminescence at room temperature in the solid state.

KEYWORDS:

• transition metal complex
• 3,5-bis((4’-carboxylbenzyl)oxy)benzoic acid
• 4′-(4-pyridyl)-2,2′:6′,2″-terpyridine
• crystal structure
• photoluminescence
• magnetic property

Funding

The authors gratefully acknowledge the financial support of the National Natural Science Foundation (No. 21576112, 21546006, 21607051), Natural Science Foundation Project of Jilin Province (20150623024TC-19) and the Science and Technology Development Plan of Siping City (2015049).

Supplementary material

Crystallographic data (excluding structure factors) for the structural analysis have been deposited with the Cambridge Crystallographic Data Center as supplementary publication Nos. CCDC 1439228(1), 1439230(2) and 1445057(3).