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The design and synthesis of some cyclometalated iridium(III) complexes containing quinoline-type ligands as ancillary ligands are reported. The emission spectra of Ir(III) complexes containing a quinolinolate (6, 8, 10) moiety exhibit a single emission peak at ca. 590 nm, resulting in a red colored emission. However, Ir(III) complexes containing 8-sulfonamidoquinoline ligands (11, 13-21) exhibit two different emission peaks (dual emission) at ca. 500 nm and ca. 600 nm upon excitation at 366 nm, resulting in a red-colored emission for 11 and a pale yellow-colored emission for 14-18 at 298 K. Especially, a white emission was observed for 19 at 298 and 77 K in dimethyl sulfoxide. The mechanistic studies based on time-dependent density functional theory calculations and time-resolved emission spectroscopy suggest that this dual emission originates from two independent emission states.

Forty Candidate Plus Trees (CPTs) of Pongamia pinnata were selected based on the morphometric traits to identify suitable seed sources with high oil content and for production of quality seedlings for mass afforestation in different forestry and agroforestry programmes. Significant genetic variability and association were recorded among 40 CPTs for pod and seed traits. Maximum 100-seed weight (186.80 g) and pod-weight (403.94 g) was recorded in CPT-33, while CPT-18 showed maximum oil content (44.07%). In general, phenotypic coefficient of variation was higher than genotypic coefficient of variation indicating the predominant role of environment. High heritability (broad sense) and genetic gain observed for pod-seed ratio (99.00%, 87.78%), 100-seed weight (100.00%, 66.99%) and 100-pod weight (98.00%, 57.38%), respectively indicate additive gene action. Seed weight and pod weight showed positive and significant correlation with oil content. CPTs 18, 20, 33, 13 and 29 were found to be the best on the basis of oil content and pod-seed characters.

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We report on the efficient synthesis of tris-heteroleptic iridium (Ir) complexes based on the degradation of tris-cyclometalated Ir complexes (IrL, L: cyclometalating ligand) in the presence of Brønsted and Lewis acids such as HCl (in 1,4-dioxane), AlCl, TMSCl, and ZnX (X = Br or Cl), which affords the corresponding halogen-bridged Ir dimers (μ-complexes). Tris-cyclometalated Ir complexes containing electron-withdrawing groups such as fluorine, nitro, or CF moieties on the ligands were less reactive. This different reactivity was applied to the selective degradation of heteroleptic Ir complexes such as fac-Ir(tpy)(Fppy) (fac-12) (tpy: 2-(4'-tolyl)pyridine and Fppy: 2-(4',6'-difluorophenyl)pyridine), mer-Ir(tpy)(Fppy) (mer-12), and mer-Ir(mpiq)(Fppy) (mer-15) (mpiq: 1-(4'-methylphenyl)isoquinoline). For example, the reaction of mer-12 with ZnBr gave the heteroleptic μ-complex [{Ir(tpy)(Fppy)(μ-Br)}] 27b as a major product, resulting from the selective elimination of the tpy ligand of mer-12, and treatment of 27b with acetylacetone (acacH) afforded the corresponding tris-heteroleptic Ir complex Ir(tpy)(Fppy)(acac)18. In addition, another tris-heteroleptic Ir complex 35a having 8-benzenesulfonylamidoquinoline (8BSQ) ligand was synthesized. Mechanistic studies of this degradation reaction and the photochemical properties, especially a dual emission, of these newly synthesized tris-heteroleptic Ir complexes are also reported.

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