Syntheses and structures of new blue luminescent B(III) and Al(III) complexes: BPh2(acac-azain) and Al(CH3)(acac-azain)2, acac-azain=1-N-7-azaindolyl-1,3-butanedionato

A luminescent boron difluoride derivative of the YELLOW 101 dye

Inspired on the outstanding behavior of the BODIPY dye, a new fluorescent boron fluoride derivative of the classical 2,2'-dihydroxy-1,1'-naphtalazine or YELLOW 101 dye has been synthesized and investigated in this work. Analogously to YELLOW 101 (λ_emission = 510 nm), the new species, here denoted BYELLOW 101, exhibits strong fluorescence around 570 and 535 nm in the solid form and in organic solvents, respectively. The observed red shift of the luminescence emission can be explored in the superparamagnetic fluorescent materials employed in MPI (magnetic particle inspection) technology, decreasing the influence of the FRET mechanism, - a critical limitation in this type of system. BYELLOW 101 is stable in solid form, but in organic solvents, it hydrolyses very slowly regenerating the initial dye, keeping the fluorescence emission but exhibiting a small blue shift along the time.

Synthesis and characterization of the complexes of pentane-2,4-dione with nickel(II) and cobalt(III): [Ni(acac)2].0.5CH3OH and [Co(acac)2NO3].2H2O (acac = pentane-2,4-dione)

Two mononuclear complexes, [Ni(acac)2].0.5CH3OH (1) and[Co(acac)2NO3].2H2O (2) (acac = pentane-2,4-dione), have been synthesized and characterized by single crystal X-ray analysis. Complex 1 crystallizes in the monoclinic space group P2(1)/c with a = 9.295(4), b = 11.450(5), c = 12.974(6) A, V = 1379.1(11) A(3),beta = 92.854(7), and Z = 4. Complex 2 crystallizes in the triclinic space group P(-1) with a= 8.153(9), b = 9.925(11), c = 10.355(12), V = 746.3(15) A(3), alpha = 70.530(16), beta =71.154(15), gamma = 80.698(16) and Z = 2. Complex 1 has a one-dimensional chain-like structure, which is extended by weak hydrogen contacts, while complex 2 shows a three-dimensional network structure.

Isomerism of bis(7-azaindolyl)methane

Three isomers of bis(7-azaindolyl)methane have been synthesized and fully characterized. Isomers 1 and 2 contain 7-azaindolyl groups that are bound to the CH(2) group through nitrogen atoms. However, 1 contains two "normal" 7-azaindolyl groups, whereas 2 contains both a normal 7-azaindolyl group and a tautomer form of 7-azaindolyl. The third isomer 4 contains two 7-azaindolyl groups that are bound to the CH(2) group through the carbon atom at the position-3. These three isomers show distinct absorption and emission spectra, attributable to the different forms of 7-azaindolyl groups in the isomers, as indicated by the results of ab initio calculations. [structure: see text]

Syntheses, structures, and electroluminescence of Ln(2)(acac-azain)(4)(mu-acac-azain)(2) [acac-azain = 1-(N-7-azaindolyl)-1,3-butanedionato, Ln = Tb(III) and Y(III)]

Two new luminescent lanthanide complexes Ln(2)(acac-azain)(4)(mu-acac-azain)(2) [acac-azain = 1-(N-7-azaindolyl)-1,3-butanedionato, Ln = Tb(III), 1, Y(III), 2] have been synthesized and structurally characterized. These two dinuclear complexes are isostructural with the two lanthanide ions being bridged by two acac-azain ligands. Each of the two metal ions is further chelated by four oxygen atoms from two acac-azain ligands, resulting in a coordination number eight for each metal ion. 1 displays characteristic Tb(III) emission bands while 2 displays weak blue luminescence attributable to the ligand. Single-layer and double-layer electroluminescent devices for compound 1 were fabricated, where compound 1 doped PVK layer functions as both the emitting layer and the hole transport layer and PBD functions as an electron transport layer (in the double-layer device), demonstrating that compound 1 is a promising green emitter in electroluminescent devices.