A Single Crystal Hybrid Ligand Framework of Copper(II) with Stable Intrinsic Blue-Light Luminescence in Aqueous Solution

Abstract

Single-crystal solid–liquid dual-phase hybrid organic–inorganic ligand frameworks with reversible sensing response facilitated by external stimuli have received significant attention in recent years. This report presents a significant leap in designing electronic structures that display reversible dual-phase photoluminescence properties from single-crystal hybrid ligand frameworks. Three-dimensional Cu(C3N2H4)4Cl2 complex frameworks were formed through the intermolecular hydrogen bonding and π⋯π stacking supramolecular interactions. The absorption band peaks at 627 nm were assigned to d–d transition showing 10Dq = 15,949 cm−1 and crystal field stabilization energy (CFSE) = 0.6 × 10Dq = 114.4 kJmol−1, while the ligand-to-metal charge transfer (LMCT) of complexes was displayed at 292 nm. The intense luminescence band results from LMCT present at 397 nm. Considering its structure, air stability, framework forming and stable luminescence in aqueous solution, the Cu(C3N2H4)4Cl2 complex shows potential for luminescence Cu-based sensors using emission intensity to detect heavy metal ion species.

Fabrication of Spiny-like Spherical Copper Metal–Organic Frameworks for the Microextraction of Arsenic(III) from Water and Food Samples before ICP-MS Detection

“…Peaks relating to C-N stretching were found in the region between 1100 cm −1 and 1400 cm −1 . The XRD analysis confirmed the crystalline structure of the formed SSC-MOFs, with peaks at 2θ of 10.8, 11.3, 15.6, 16.5, 18.7, 19.9, 20.3, 32 and 34, as presented in the inset graph (Figure 5), in addition to the patterns detected at 37.4, 43.5, 76.9 and 81.17 [65][66][67]. These results indicate that the copper ions inside the MOF structure may have more than one transition state, which may be due to the occurrence of a co-ordination with oxygen atom in water molecules simultaneously with bonding formed to nitrogen from the imidazole ligand [66,68].…”

Methanol‐Induced Crystallization of Chiral Hybrid Manganese (II) Chloride Single Crystals for Achieving Circularly Polarized Luminescence and Second Harmonic Generation

“…As we know, the Jahn‐Teller (JT) effect strongly leads to the electron distribution that affects the arrangement of atoms in the crystal structure and the buckling of the inorganic lattice. [ 62–66 ] Thus, it is easy for NPA‐based Cu (II) hybrid materials to form but difficult for NPA‐based Mn (II) hybrid materials to form. After the crystallization of (R/S‐NPA) 2 CuCl 4 , the concentration of Cu 2+ ions in solution decreases.…”

“…[62,63] Thus, Jahn-Teller distortions prompt the formation of copper (II) coordination leading to the abundant Cu (II)-ligand bond geometries. [64] This strong JT effect caused the Cu(II)-based octahedra to elongate and led to a better fit of cations in the accessible space between chains. [65,66] However, Mn (II)-based coordination exhibited no Jahn-Teller distortions, which is difficult to obtain different Mn (II)-ligand bond geometries with largesize organic cations in the accessible space between chains.…”

“…As we know, the Jahn-Teller (JT) effect strongly leads to the electron distribution that affects the arrangement of atoms in the crystal structure and the buckling of the inorganic lattice. [62][63][64][65][66] Thus, and S8 (Supporting Information). The core Mn 2p peaks of (R/S-MBA)MnCl 3 •CH 3 OH located at ≈641.4 and 652.6 eV are attributed to Mn 2p 3/2 and Mn 2p 1/2 .…”

Lead-Free Low-Dimensional Tetraalkylammonium Manganese- and Copper-Based Hybrid Organic–Inorganic Perovskites for Visual Fluorometric Pb2+ Ion Detection

“…All compounds 1, 2, 3, and 4 are decomposed mainly in two steps, as shown in Figure S9(a)−(d), which are well-matched with the previously reported Mn-and Cu-based hybrids compounds. 26,29,52,55 Both 1 and 3, with TEA as an organic part, show a similar weight loss characteristic, where the first stage (∼220−300 °C) is associated with the carbonization of the cation part and metal bromide formation, whereas the second stage (∼300−400 °C) mostly corresponds to metal bromide and metal oxide residue formation [Figure S9(a),(c)]. 26 Similarly, Figure S9(b) and S9(d), with TBA as an organic part, show the TGA spectra for compounds 2 and 4, which are well-matched with the previously reported copper bromide-based organic hybrid compounds, where the compound was stable until 220 °C.…”