A detailed experimental characterization and theoretical evaluation of optical as well as other relevant physicochemical properties of a series of 9,10-dihydro-9,10-diboraanthracene bis(8-oxyquinolinates) and a few other related systems is reported. The obtained compounds exhibit green luminescence with quantum yields of emission up to 63% in CH 2 Cl 2 . Single crystal X-ray diffraction studies indicate that 9,10-dihydro-9,10-diboraanthracene complexes exist either as bent conformers (stabilized by a weak intramolecular CH…O interaction bringing two 8-oxyquinolinato ligands closer to each other) or symmetrical ones (bearing both ligands related by the centre of symmetry and separated one from the other). Theoretical calculations revealed that the LUMO levels are lower for the bent conformers than for the symmetrical ones. This suggests that the luminescent properties of the studied compounds are affected by their specific structural properties. The obtained compounds were used as emitters for the construction of organic light emitting diodes (OLEDs). The highest luminance of ca. 2,000 cd·m −2 was recorded for the device containing only 2.0 wt% of 1,6-difluoro-9,10-dihydro-9,10-diboraanthracene core in the poly(Nvinylcarbazole/2-t-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PVK:PBD) matrix. The fabricated OLEDs exhibit current efficiency in the range from 0.5 to 1.1 cd·A −1 .
Al arge-scale synthesis of knownR uo lefin metathesis catalyst VII featuring an unsymmetrical N-heterocyclic carbene (NHC) ligand with one 2,5-diisopropylphenyl (DIPP) and one thiophenylmethylene N-substituent is reported. The optimised procedure does not requirec olumnc hromatography in any step and allows forp reparation of up to 0.5 kg batches of the catalystf rom simple precursors.T he application profile of the obtainedc atalystw as studied in environmentally friendly dimethyl carbonate (DMC). Although VII exhibited low efficiency in cross-metathesis (CM) with electron deficient partners, good to excellent results were noted for substrates featuring easyt oi somerise CÀCd ouble bonds. This includes polyfunctional substrates of medicinal chemistry interest, such as analogues of psychoactive 5F-PB-22 and NM-2201 and two PDE5i nhibitors-Sildenafil and Vardenafil. Finally,al arger scale ring-closing metathesis (RCM) of aV ardenafil derivativew as conducted in DMC, allowing for straightforwardi solation of the expectedp roduct (23 g) in high yield and with low Ru contamination level (7.7 ppm).
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