Chiral Silver–Lanthanide Metal–Organic Frameworks Comprised of One-Dimensional Triple Right-Handed Helical Chains Based on [Ln₇(μ₃-OH)₈]¹³⁺ Clusters

Abstract

Three new isostructural chiral silver-lanthanide heterometal-organic frameworks [AgLn(μ-OH)(bpdc)(NO)(HO)](NO)·2HO [Ln = Eu (1), Tb (2, Sm (3); Hbpdc = 2,2'-bipyridine-3,3'-dicarboxylic acid] based on heptanuclear lanthanide clusters [Ln(μ-OH)] comprised of one-dimensional triple right-handed helical chains were hydrothermally synthesized. Various means such as UV-vis spectroscopy, IR spectroscopy, elemental analysis, powder X-ray diffraction, and thermogravimetric/differential thermal analysis were used to characterize the compounds, wherein compound 3 was crystallographically characterized. In the structure of compound 3, eight μ-OH groups link seven Sm ions, forming a heptanuclear cluster, [Sm(μ-OH)], and the adjacent [Sm(μ-OH)] clusters are linked by the carboxylic groups of bpdc ligands, leading to the formation of a one-dimensional triple right-handed helical chain. The adjacent triple right-handed helical chains are further joined together by coordinating the pyridyl N atoms of the bpdc ligands with Ag, resulting in a chiral three-dimensional silver(I)-lanthanide(III) heterometal-organic framework with one-dimensional channels wherein NO anions and crystal lattice HO molecules are trapped. The compounds were studied systematically with respect to their photoluminescence properties and energy-transfer mechanism, and it was found that Hbpdc (the energy level for the triplet states of the ligand Hbpdc is 21505 cm) can sensitize Eu luminescence more effectively than Tb and Sm luminescence because of effective energy transfer from bpdc to Eu under excitation in compound 1.

Monitoring Ultraviolet Radiation Dosage Based on a Luminescent Lanthanide Metal–Organic Framework

“…Tb atoms adopt three different coordination environments in Tb-IDA. Both Tb1 and Tb2 centers display nine-coordinate tricapped trigonal prismatic geometry, while Tb3 resides in eight-coordinate snub disphenoid polyhedra. , The Tb–O bond lengths are all within the range from 2.289 to 2.536 Å (Table S3) and are similar to previously reported distances for trivalent Tb–O compounds . Three Tb1 atoms are connected by a μ 3 -OH to form a trinuclear unit [Tb 3 (μ 3 –OH)] 8+ .…”

Various Silver Phosphinate Inorganic Architectures in Three-Dimensional Frameworks with Argentophilic Interactions

“…The most intriguing characteristic of the structure is the existence of a 3D inorganic skeleton in 3 , which is a very important part to bolster the framework. The 3D inorganic skeleton (Figure d) is generated from silver phosphinite chain (Figure e) joined by Ag–Ag interactions (Ag1–Ag1 2.968(3) Å and Ag4–Ag4 2.9731(17) Å), which has never been reported in Ag compounds up to now. ,− Moreover, the Ag–Ag interactions between neighboring chains are strengthened by isophthalate groups of (L 3 ) 5– ligands.…”

Synthesis and characterization of single-phase Tb3+/Eu3+ doped metal–organic framework phosphors for warm light WLED applications

“…29 The Δ E of H 2 bpdc (S 1 : 34 014 cm −1 and T 1 : 21 505 cm −1 ) was 12 509 cm −1 , which indicates that the ISC process might be effective. 30 Based on the luminescence characterization, there might be two energy transfer ways in Ln@bio-MOF-1 (Fig. 7).…”