Diarylphosphate as a New Route for Design of Highly Luminescent Ln Complexes

Abstract

Organophosphate-chloride complexes [{(2,6-iPr2C6H3-O)2POO}2LnCl(CH3OH)4]·2CH3OH, Ln = Nd (1), Eu (2), Gd (3), and Tb (4) have been obtained and structurally characterized. Their reaction with 2,2′:6′,2″-terpyridine leads to the formation of 1:1 adducts ([{(2,6-iPr2C6H3-O)2POO}2LnCl(terpy)(H2O)2(CH3OH)], Ln = Eu (5), Gd (6), Tb (7) with exception of Nd, where tris-diisopropylphenylphosphate complex [{(2,6-iPr2C6H3-O)2POO}3Nd) (terpy)(H2O)(CH3OH)] (8) was obtained due to the ligand metathesis. A bright luminescence observed for the Eu and Tb organophosphate complexes is the first example of an application of organophosphate ligands for 4f-ions luminescence sensitization. Photophysical properties of all complexes were analyzed by optical spectroscopy and an energy transfer scheme was discussed. A combination of two types of ligands into the coordination sphere (phosphate and phenanthroline) allows designing the Eu surrounding with very high intrinsic quantum yield QEuEu (0.92) and highly luminescent Ln complexes for both visible and near-infrared (NIR) regions.

Air‐Stable Solid‐State Photoluminescence Standards for Quantitative Measurements Based on 4′‐Phenyl‐2,2′ : 6′,2′′‐Terpyridine Complexes with Trivalent Lanthanides

“…For their Tb 3+ analogues, they are 28.9(5) %/0.7077(6) ms for 2‐Tb and 23.0(4) %/0.4122(5) ms for 3‐Tb , noticeably lower than for 1‐Tb . The observed lifetimes and quantum yields of the complexes obtained are well comparable to trivalent europium and terbium coordination compounds with efficient sensitiser ligands, [57,72–76] especially with 2,2′ : 6′,2“‐terpyridine derivatives [50,52,55,67] . Simultaneous thermal analyses of 2‐Ln and 3‐Ln are presented in the SI (Figures S17‐S20).…”

Enhancing the Analysis of Eu3+ Photoluminescence in Coordination Compounds in the Solid State by Determining their Refractive Index

“…3. molecule, observed for Ln 3 + complexes before. [10] A lower Φ obs for 8 (19.3(4) %) than for 5 (33.4(9) %) is the result of the lower ligand sensitisation efficiency. For complexes 1-7, η sens is between 78 and 92 % (Table 1), while for product 8 it is 45 %.…”

“…Photoluminescence properties of Ln 3 + are generally studied in inorganic [1][2][3] or coordination compounds. [4][5][6][7][8][9][10][11] Furthermore, these metal ions could be used as dopants [12][13][14][15][16] or embedded in polymeric films. [17][18][19][20][21] In suitable coordination compounds, the organic ligand acts as an "antenna" for the sensitisation of Ln 3 + luminescence, being beneficial due to the low light uptake of lanthanide ions employing intra-4 ftransitions.…”

Eu3+‐doped LaF3‐based inorganic–organic hybrid nanostructured materials for broad‐spectrum excitation and strong photoluminescence

“…At this time, lanthanides coordination compounds [ 1 ] have been widely investigated due to their potential applications in photoluminescence materials, biological probes, solar cells, and other fields. [ 2–6 ] As one of the excellent host materials for Ln 3+ exciters, LaF 3 nanocrystals are characterized by low vibrational energy (~350 cm −1 ), and high thermal and environmental stability. [ 7–9 ]…”

“…[22][23][24][25] It also will be helpful to improve the conversion efficiency of silicon solar cells by converting the UV light to visible light, because silicon solar cells generally have low quantum efficiency in the UV spectrum but high efficiency in the visible range. [26] Shahi and colleagues [27] synthesized the Eu(TTA) 3 Phen complex and indicated it could detect low intensity UV light due to the efficient energy transfer from ligand to Eu 3+ ions.…”