Controlling dimensionality via a dual ligand strategy in Ln-thiophene-2,5-dicarboxylic acid-terpyridine coordination polymers

Abstract

Eleven new lanthanide (Ln = Nd-Lu)-thiophene-2,5-dicarboxylic acid (25-TDC)-2,2':6',2''-terpyridine (terpy) coordination polymers () which employ a dual ligand strategy have been synthesized hydrothermally and structurally characterized by single crystal and powder X-ray diffraction. Two additional members of the series ( and ) were made with Ce(3+) and Pr(3+) and characterized via powder X-ray diffraction only. The series is comprised of three similar structures wherein differences due to the lanthanide contraction manifest in Ln(3+) coordination number as well as the number of bound and solvent water molecules within the crystal lattice. Structure type I (Ce(3+)-Sm(3+)) contains two nine-coordinate Ln(3+) metal centers each with a bound water molecule. Structure type II (Eu(3+)-Ho(3+)) features a nine and an eight coordinate Ln(3+) metal along with one bound and one solvent water molecule. Structure type III (Er(3+)-Lu(3+)) includes two eight-coordinate Ln(3+) metal centers with both water molecules residing in the lattice. Assembly into supramolecular 3D networks via π-π interactions is observed for all three structure types, whereas structure types II and III also feature hydrogen-bonding interactions via the well-known C-HO and O-HO synthons. Visible and near-IR luminescence studies were performed on compounds , , , and at room temperature. As a result characteristic near-IR luminescent bands of Pr(3+), Nd(3+), Sm(3+), and Yb(3+) as well as visible bands of Sm(3+) were observed.

Two Series of Lanthanide Coordination Polymers and Complexes with 4′‐Phenylterpyridine and their Luminescence Properties

“…Quantum yields of the Dy 3+ , Pr 3+ , Ho 3+ , and Tm 3+ products obtained could not be determined reliably due to low intensity of emission in the visible, and of Nd 3+ and Yb 3+ products due to emission in the NIR. However, the respective metal ion based emission lifetimes were also successfully determined for the Dy 3+ , Pr 3+ , Ho 3+ , Tm 3+ , and Yb 3+ products (Table ), which are also close to the values presented in the literature , …”

Three-dimensional terbium(III) metal–organic framework constructed by thiophene-2,5-dicarboxylate: synthesis, crystal structure and fluorescent properties

“…Metal-organic frameworks (MOFs) have attracted great interests due to the fluorescent properties [1][2][3][4][5], as well as the significant applications, such as magnetism [6][7][8], gas adsorption and separation [9][10][11], sensors or detectors [12][13][14][15][16][17], proton conduction [18], etc. Lanthanide coordination polymers including lanthanide-organic frameworks, one of the important MOFs, are generally synthesized by hydrothermal methods which require high pressure and high temperature that has impeded scalable synthesis of lanthanide MOFs and their industrial utilization [19][20][21]. Other reported synthetic methods such as solvothermal, microwave-assisted solvothermal, and sonochemical synthesis are also energy consumable [22][23][24].…”

Probing the Influence of N‐Donor Capping Ligands on Supramolecular Assembly in Molecular Uranyl Materials

“…Polypyridyl chelating N‐donors feature relatively large binding affinities for f‐element ions (specifically the [UO 2 ] 2+ cation) 36. Some of the ligands of this class, such as 1,10‐phenanthroline (phen) and 2,2′:6′,2″‐terpyridine (terpy) (and its derivatives), have been explored as “capping” ligands in the synthesis uranyl coordination polymers,18,37–40 molecular uranyl materials,41–44 and lanthanide hybrid materials 45–47. Herein we are using these ligands explicitly as tools for crystal engineering by the chelation of part of the equatorial uranyl coordination sphere, thus promoting further assembly by halogen or hydrogen bonding, π–π stacking interactions, or a combination thereof.…”