The crown-ether coordination compounds ZnX 2 (18-crown-6), EuX 2 (18-crown-6) (X: Cl, Br, I), MnI 2 (18crown-6), Mn 3 Cl 6 (18-crown-6) 2 , Mn 3 I 6 (18-crown-6) 2 , and Mn 2 I 4 (18-crown-6) are obtained by ionic-liquid-based synthesis. Whereas MX 2 (18-crown-6) (M: Zn, Eu) show conventional structural motives, Mn 3 Cl 6 (18-crown-6) 2 , Mn 3 I 6 (18-crown-6) 2 , and Mn 2 I 4 (18-crown-6) exhibit unusual single MnX 4 tetrahedra coordinated to the crown-ether complex. Surprisingly, some compounds show outstanding photoluminescence. Thus, rare Zn 2+ -based luminescence is observed and unexpectedly efficient for ZnI 2 (18-crown-6) with a quantum yield of 54%. Unprecedented quantum yields are also observed for Mn 3 I 6 (18-crown-6) 2 , EuBr 2 (18-crown-6), and EuI 2 (18-crown-6) with values of 98, 72, and 82%, respectively, which can be rationalized based on the specific structural features. Most remarkable, however, is Mn 2 I 4 (18crown-6). Its specific structural features with finite sensitizer−activator couples result in an extremely strong emission with an outstanding quantum yield of 100%. Consistent with its structural features, moreover, anisotropic angle-dependent emission under polarized light and nonlinear optical (NLO) effects occur, including second-harmonic generation (SHG). The title compounds and their optical properties are characterized by single-crystal structure analysis, X-ray powder diffraction, chemical analysis, density functional theory (DFT) calculations, and advanced spectroscopic methods.

By using a layer‐by‐layer (LbL) approach, lanthanide‐based, monolithic metal–organic framework (MOF) thin films are fabricated for optical applications. In particular, the LbL approach allows manufacturing of heteroepitaxial Tb(III)‐Eu(III)(BTC) coatings with precise thickness control. Adjusting the Tb(III)‐to‐Eu(III) ratio allows tuning of the emission color. The hetero‐multilayer architecture makes it possible to suppress the direct Tb(III)‐to‐Eu(III) energy transfer, an unwanted phenomenon present in the corresponding mixed‐metal bulk MOF structures. The resulting Ln‐MOF thin films, or Ln‐surface‐anchored MOFs (SURMOFs), are characterized by X‐ray diffraction, infra‐red reflection absorption spectroscopy, UV–vis, and photoluminescence measurements. The results demonstrate that the heteroepitaxial SURMOF architectures carry huge potential for fabricating optical coatings for a wide range of applications.

The positively charged and weakly polarizable s-block metals commonly do not usually have phosphine ligands in molecular complexes. Herein, we report mono- and dinuclear small diamidophosphine complexes of the alkaline-earth metals Mg, Ca, and Sr, which were prepared from simple precursors and a phosphine-functionalized diamine ligand N,N-bis(2-(diphenyl-phosphino)phenyl)ethane-1,2-diamine (PNHNHP). The alkaline-earth metal based complexes [(PNNP)Mg] and [(PNNP)M(thf) ] (M=Ca, Sr), exhibit unusual coordination spheres and show bright fluorescence, both in the solid state and in solution. For comparison, the even stronger luminescent Al and Zn complexes [(PNNP)Zn] and [(PNNP)AlCl] were prepared. Emission lifetimes in the nanosecond range and high photoluminescence quantum yields up to 93 % are observed at room temperature.

The prolific topic of development of solidstate lighting devices has focused over the last years on solid-state white light (SSWL) emitting materials, mainly due the long operation lifetime and excellent harvesting and saving energy. [1] Even today, incandescent and mercury-based fluorescent materials are employed as white-light sources due to their superior warm-white light impression. Moreover, the fabrication of environmentally safe white light-emitting diode (LEDs) with a "warm-white" impression remains still a challenge. Many of the "white" organic light-emitting diode/ LED materials cover only part of the visible spectrum and lack the required efficacy of 150-200 lm W −1 for white-light performance. [2] For this reason, the design of a new generation of SSWL materials is of continuous interest in materials science, especially in areas such as full-color flat-panel electroluminescent displays for mobile devices, optical telecommunications, lighting, and backlighting for liquid-crystals displays. [3] Besides, high-quality white-light performance requires the Commission International de l'Eclairage (CIE) x,y coordinates 0.333, 0.333, with a correlated color temperature (CCT) into the 2500-6500 K, and color rendering index above 80 which are standard requirements for lighting applications. [4] One of the explored strategies to obtain white light is by combining red, green, and blue (RGB) sources to cover the visible region (400-700 nm) in the electromagnetic spectrum. [5] Also, metal-organic frameworks (MOFs) have been the focus of interest due to their potential applications in gas storage/ separation , [6] catalysis, [7] optics, [8] magnetism, [9] sensing, [10] and biomedicine. [4,11,12] Due to a permanent porosity, structural diversity, functionalization capabilities and then, tunable luminescence, MOF possess interesting properties for the development of SSWL composites. In recent years, a large number of luminescent MOFs have been reported for this purpose. [5,13-24] Moreover, for uses in nanotechnology, it is mandatory that MOFs are anchored on solid substrates, being particularly evident in the case of optoelectronic applications. [25,26] According to specialized reviews such as those from Wöll group, [27] it is distinguishable the surface-supported metal-organic frameworks (SURMOFs) devices, fabricated using layer-by-layer (LbL) A new set of Ln-MOF (lanthanide-metal-organic framework) thin films, known as Ln-SURMOFs (surface-supported MOFs), is fabricated with a layer-by-layer, in order to generate solid-state white-lighting devices. A three-component approach is carried out for a rational combination of red, green, and blue (RGB) emitting Eu 3+ , Tb 3+ , and Gd 3+ containing layers in order to achieve white-light emission. The Ln-SURMOFs are fully characterized by powder X-ray diffraction, infrared reflection-absorption spectroscopy, scanning electron microscopy, and photoluminescence spectroscopy (excitationemission and chromaticity determination according to Commission International de l'Eclairage, C...

Inorganic-organic hybrid nanoparticles (IOH-NPs) with a general composition [ZrO] 2 + [R Dye OPO 3 ] 2À , [Ln] 3 + n/3 [R Dye (SO 3 ) n ] nÀ , [Ln(OH)] 2 + n/2 [R Dye (SO 3 ) n ] nÀ , or [LnO] + n [R Dye (SO 3 ) n ] nÀ (Ln: lanthanide) are a novel class of nanomaterials for fluorescence detection and optical imaging. IOH-NPs are characterized by an extremely high load of the fluorescent dye (70-85 wt-%), high photochemical stability, straightforward aqueous synthesis, low material complexity, intense emission and high cell uptake at low toxicity. Besides fullcolor emission, IOH-NPs are suitable for multimodal imaging, singlet-oxygen generation as well as drug delivery and drug release. This focus review presents the material concept of the IOH-NPs as well as their synthesis and characterization. Their characteristic features are illustrated by selected in vitro and in vivo studies to initiate application in biology and medicine.[a] B.