Novel Ir(III) Complexes with NHC-Based Ancillary Ligands for Efficient Nondoped OLEDs.

Nondoped organic light-emitting diodes (OLEDs) are of paramount importance for display and lighting applications owing to their advantages of facile fabrication and outstanding stability. However, nondoped OLEDs achieving extraordinary electroluminescence (EL) performance and low turn-on voltage (Von) remain sparse. Here, three Ir(III) complexes featuring N-heterocyclic carbene (NHC) auxiliary ligands functionalized with electron-deficient aromatic sulfonyl or phosphine oxide groups are reported as promising emitters for nondoped OLEDs. All Ir(III) complexes exhibit green emission with relatively high neat film efficiency. Although the photoluminescence spectra of three complexes reveal similarities, there are distinct differences in the nondoped EL performance. The nondoped device N3 based on tBu-Ir-ISO displays the most eminent EL performances and presents a low Von of 2.1 V, a power efficiency of 30.7 lm W-1, and a maximum current efficiency of 27.0 cd A-1, which can be attributed to steric hindrance and balanced carrier-transporting ability induced by electron-deficient substituents. Moreover, doped devices D1-D3 also realize excellent EL performance. It is believed that the strategy reported herein is a simple and efficient way of constructing excellent Ir(III) complexes for nondoped phosphorescent OLEDs.

[Relationships among risk knowledge, attitudes and ability to resist substance abuse in adolescents].

BACKGROUND: The Ministries of Justice and Education have implemented adolescent substance abuse prevention programs for many years. Rates of substance abuse among high school students continue to rise in spite of such programs. PURPOSE: This study investigates adolescents' substance abuse-related knowledge and attitudes and self-confidence to resist substance use in order to identify predictive factors of poor adolescent resistance to substance use. METHODS: A cross-sectional study survey gathered data on substance abuse-related knowledge and attitudes and self-confidence to resist substance use from 243 second-year senior high school students studying at two schools in northern Taiwan. RESULTS: Participants were most knowledgeable about tobacco (80.2%), followed by alcohol (72.0%), ecstasy (56.0%), and marijuana (30.0%). Only 19.3% demonstrated an understanding of the harmful effects of using Ketamine. A 10-point Likert scale measured participant substance use attitudes. Alcohol was the substance participants were most willing to use (2.18 ± 3.27), followed by tobacco (0.66 ± 2.19), ecstasy (0.45 ± 1.88), Ketamine (0.43 ± 1.93), and marijuana (0.38 ± 1.83). Participants had higher awareness of the harmful effects of Ketamine (t = -2.37, p = .018), marijuana (t = -2.33, p = .021), and tobacco (t = -2.02, p = .044), with participants reporting greater self-confidence to resist using these three substances. Multiple regression analysis found the three most important factors affecting participant self-confidence to resist substance use to be gender (ß= .26, p < .001), knowledge about the substance (ß= .15, p = .028), and attitude toward substance use (ß= -.20, p < .001). CONCLUSIONS / IMPLICATIONS FOR PRACTICE: Level of harmful effects knowledge and attitudes toward use varied among the various substances considered in this paper. Being female, having strong knowledge about the substance, and negative attitude toward substance use correlated with higher levels of self-confidence to resist substance use. Study results will be used in ongoing research designed to establish an empirical basis for adolescent substance use prevention and research, the results of which may be used directly by school nurses and military training education nurses.

Reactivity of the 16e Cp*Co half-sandwich complex containing a chelating 1,2-dicarba-closo-dodecaborane-1,2-dithiolate ligand towards alkynes.

The 16e half-sandwich complex Cp*Co(S(2)C(2)B(10)H(10))(1, Cp* = pentamethylcyclopentadienyl) reacts with N-1-naphthylpropargylamide to afford two 18e complexes (2) and (3). 2 is a 1 : 1 adduct containing a four-membered metallacycle. In 3 the alkyne is twofold inserted into one Co-S bond in a head-head mode. Reactions of 1 with 1-(2-furyl)-2-propyn-1-one and 1-ferrocenyl-2-propyn-1-one lead to two types of alkyne twofold inserted products (4)/(5) and (6)/(7), respectively. The reaction of 1 with phenylacetylene gives rise to the sole complex (8) of the same structural type as 3, 4 and 6, whereas the reaction of 1 with dimethyl acetylene dicarboxylate affords the sole 1 : 1 adduct (9). Complexes 2-9 have been characterized by IR, NMR, elemental analysis and mass spectrometry, and 3-9 have also been determined by single-crystal X-ray diffraction analysis.