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AlB4O6N, Al0.97Cr0.03B4O6N, and Al0.83Cr0.17B4O6N are the first representatives of the recently established structure‐family of oxonitridoborates containing Al3+. These compounds are isotypic to CrB4O6N and are synthesized in a multi‐anvil press under high‐pressure/high‐temperature conditions of 7.0 GPa/1350 °C. Structural refinement by single‐crystal X‐ray diffraction shows that they crystallize in the space group P63mc (no. 186) with two formula units per cell. Detailed characterization including high‐temperature X‐ray powder diffraction (HT‐XRD), electron probe microanalysis (EPMA), measurements of second harmonic generation (SHG), hardness, photoluminescence properties, vibrational spectroscopy, and band structure calculations reveal intriguing physicochemical properties that strongly resemble the famous material ruby. [ABSTRACT FROM AUTHOR]

A structural study on the solid, microcrystalline chromophore roseolumiflavin was carried out. Based on rational design considerations three binary co-crystals were prepared with a primary focus set on utilizing the imide functional group. Therefore, robust supramolecular synthons, including a carboxylic acid–amide dimer, halogen bonding, as well as a hydrogen-bonded three-point binding motif, were successfully incorporated into the multicomponent systems. All the co-crystals showed a blue-shifted fluorescence in the red range compared to the near-infrared-emitting solid roseolumiflavin. Solvatochromic studies finally elucidated that the degree of close packing between the flavin molecules within the crystal structures was decisive for the emission colour. These results render new possibilities to investigate flavins in the aspect of crystal engineering to tune optical properties of organic chromophores in the solid state. [ABSTRACT FROM AUTHOR]

In an article published in Advanced Functional Materials, Markus Suta, Hubert Huppertz, and their colleagues introduce a new oxonitridoborate compound called AlB4O6N:Cr3+. This compound exhibits a highly efficient red line emission and has the potential to serve as an alternative luminescent pressure sensor. The researchers suggest that AlB4O6N:Cr3+ could offer more precise pressure calibration in diamond anvil cells compared to the current standard, ruby. The authors express gratitude to Abraham Siedler and Marie-Theres Wildauer for their contributions to the design of the inside back cover. [Extracted from the article]

Two new scandium‐containing coordination polymers, with the formulae {(CH3)2NH2}[Sc(BPDC)2] (1) and [Sc(OH) (BPyDC)] (2) were solvothermally synthesized by using the linear linker molecules biphenyl‐4,4'‐dicarboxylic acid (H2BPDC) and 2,2'‐bipyridine‐5,5'‐dicarboxylic acid (H2BPyDC). Crystal structures were determined from single‐crystal and powder X‐ray diffraction data, respectively. The crystal structures of 1 and 2 contain isolated ScO6 or chains of trans corner‐sharing ScO6 octahedra as the inorganic building unit (IBU), which are connected by the linker molecules to a 3D framework or a layered structure, respectively. The compounds were characterized by IR‐spectroscopy, elemental analysis, thermogravimetric analysis and photoluminescence spectroscopy. 1 shows blue emission at 400 nm, while 2 exhibits intense green emission at 550 nm with a high quantum yield (QY) of 69 %. [ABSTRACT FROM AUTHOR]

The synthesis and structural characterization of 1,7-bis(4-triphenylsiloxy-3-methoxy-phenyl)-1,6-heptadiene-3,5-dione (1 = Ph 3 SiCurcH) and 1,7-bis(4-methoxycarbonyloxy-3-methoxy-phenyl)-1,6-heptadiene-3,5-dione (2 = MeOC(O)CurcH) are reported. Compound 1 represents the first metal-organic curcumin derivative. The complexation of 1 and 2 with Cu2+ has been studied. The new copper(II) complexes (Ph 3 SiCurc) 2 Cu (3) and [MeOC(O)Curc] 2 Cu·4MeCN (4) have been prepared and their crystal structures determined by single crystal X-ray diffraction. Moreover, the optical properties of the solid compound 1 have been investigated in detail. The emission spectrum shows a vibronic fine structure that has been analysed in terms of Franck-Condon factors. The excitation spectrum is broad and structureless and may be interpreted in terms of an interband transition as is also confirmed by diffuse reflectance spectra. Due to the weak intermolecular interactions, an isolated-molecule model is used instead for the assignment of the transitions, which are thus characterized as S 1 ↔ S 0 or π * ↔ π fluorescent transitions. Despite the electric-dipole allowed nature of the transition, the quantum yield is Φ = (2.4 ± 0.3)% in agreement with other findings on curcumin derivatives. • The synthesis of the first Si-based metal-organic curcumin derivative is reported. • The solid compound shows yellow luminescence due to a direct interband transition. • The vibronic fine structure is analysed with an effective Huang-Rhys-Pekar model. • An interpretation as molecular S 1 →S 0 transition despite band formation is possible • The triphenylsiloxy functional groups do not affect the optical properties. [ABSTRACT FROM AUTHOR]

The crystal structures of ³∞[RE2(ADC)3(H2O)6]·2H2O (RE = Pr, Nd, Sm, Eu, Tb, Dy) were solved and refined from X-ray single crystal data. They crystallize in a structure type already known for RE = La, Ce and Gd (P1, no. 2, Z = 2), which is characterized by REO9 polyhedra forming dimeric units being the nodes of a 3D framework structure linked by ADC²- anions (-O2C-C≡C-CO2- = acetylenedicarboxylate). From synchrotron powder diffraction data it was shown that isostructural coordination networks are formed for RE = Ho, Er, Y, whereas for RE = Tm, Yb, Lu a new structure type crystallizing in a highly complex crystal structure with a large orthorhombic unit cell is found. All compounds are obtained by slow evaporation of an aqueous solution containing RE(OAc)3·xH2O and acetylenedicarboxylic acid (H2ADC). The coordination networks of composition ³∞[RE2(ADC)3(H2O)6]·2H2O were thoroughly investigated by thermal analysis and for RE = Eu, Tb, a strong red and green photoluminescence was observed and investigated by means of UV/Vis spectroscopy. [ABSTRACT FROM AUTHOR]