Bright sky-blue fluorescence with high color purity: assembly of luminescent diphenyl-anthracene lutetium-based coordination polymer

Pure sky-blue fluorescence (FWHM: 50 nm) from lutetium-based coordination polymer with diphenyl-anthracene derivative is demonstrated for the first time. The observed high color purity is based on the tightly packed crystal structure of the coordination polymer with multiple CH–F interactions.

mL) and a 30% H 2 O 2 aqueous solution (2 mL) was added to the solution. The reaction mixture was stirred for 5 h. The product was extracted using CHCl 3 and washed with distilled water. The solvent was then evaporated to produce a powder. The recrystallization was performed using CH 2 Cl 2 /MeOH solvent (Yield: 210mg, 28%).   Single-Crystal X-ray Structure Determination: X-ray crystal structures and crystallographic data for DPA-P and [Lu(hfa) 3 DPA-P] obtained by the recrystallization process using the CH 3 OH (Lu(hfa) 3 (H 2 O) 2 ) / CH 2 Cl 2 (DPA-P ligand) solvent system are shown in Fig. 2 and Table S1. X-ray crystal structures and crystallographic data for [Lu(hfa) 3 DPA-P] obtained by the recrystallization process using the CHCl 3 (Lu(hfa) 3 (H 2 O) 2 ) / CH 2 Cl 2 (DPA-P ligand) solvent system is shown in Fig.   S5 and Table S3. Single crystals of the compounds were mounted on micromesh (MiTeGen M3-L19-25L) using paraffin oil. Measurements were made by using a Rigaku RAXIS RAPID imagingplate area detector or XtaLAB AFC11 (RCD3) with graphite-monochromated Mo-Kα radiation.
Non-hydrogen atoms were anisotropically refined. All calculations were performed using a crystalstructure crystallographic software package. The CIF data were confirmed by the check CIF/PLATON service. CCDC-2046734 (for DPA-P), CCDC-2046736 (for [Lu(hfa) 3 DPA-P] n obtained by the recrystallization process using the CH 3 OH/CH 2 Cl 2 solvent system), and CCDC-2058490 (for [Lu(hfa) 3 DPA-P] n obtained by the recrystallization process using the CHCl 3 /CH 2 Cl 2 solvent system) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.

S3. Shape measure calculation
To clarify the polyhedral structure, we calculated continuous shape measures. The continuous shape measure factor, S, was calculated to estimate the degree of distortion in the first coordination sphere of the coordination structure based on the crystal structure data. The S value is given by the following equation, where Q k represents the vertices of the actual structure, Q 0 is the center of mass of the actual structure, N is the number of vertices, and P k represents the vertices of the ideal structure. Based on the shape measure calculation, [Lu(hfa) 3 DPA-P] n was categorized as having SAP coordination geometry (S = 0.844).  Fig. S2. The X-ray crystal structures of the [Lu(hfa) 3 DPA-P] n obtained by the recrystallization process using the CH 3 OH/CH 2 Cl 2 solvent system (a: Lu(hfa) 3 (DPA-P) 2 without F atom, b: Lu 2 (hfa) 6 (DPA-P) 3 without F atom; c: Packing structure in [Lu(hfa) 3 DPA-P] n (Blue broken line: CH-F interaction). obtained by the recrystallization process using the CH 3 OH/CH 2 Cl 2 solvent system, and prompt curves (a, b, broken line).

CHCl 3 /CH 2 Cl 2 solvent system
We also prepared single crystals of [Lu(hfa) 3 DPA-P] n by recrystallization from the CHCl 3 /CH 2 Cl 2 solvent system (Fig S5). The crystal was identified by elemental analysis (C 65 H 39 F 18 O 8 P 2 Lu calcd for C 51.13, H 2.57, found: C 50.87, H 2.47). The structure of the obtained crystal (Fig. S5, Table   S3) is different from that of the single crystals obtained by recrystallization from the CH3OH/CH2Cl2 solvent system (Fig. 2b, Table S1). The structure of the [Lu(hfa) 3 DPA-P] n crystal obtained from the CHCl 3 /CH 2 Cl 2 solvent system belongs to the P2 1 space group (Table S3). The CH-F interactions (< 3.0 Å) between the hfa unit and the aromatic DPA-P ligands were also observed in the [Lu(hfa) 3 DPA-P] n (Fig. S5).  The emission and excitation spectra are shown in Fig. S6. The FWHM is estimated to be 63 nm and is narrower than that of the DPA-P ligand (77 nm). The emission quantum yield upon excitation at 380 nm is estimated to be 30% and is higher than that of the DPA-P ligand (18%). The results also support our concept; the characteristic lanthanide fixation system improved the emission color purity and emission quantum yield.
(b) [Lu(hfa) 3 DPA-P] n in their solid states, which is obtained by the recrystallization process using the CHCl 3 /CH 2 Cl 2 solvent system. The samples were 3000-fold dilution using KBr.