Deep blue phosphorescent iridium(III) cyclometalates with o-carboranes

Publication date: 1 September 2018 Source:Journal of Organometallic Chemistry, Volume 870 Author(s): Minji Kim, Min Hyung Lee Heteroleptic iridium(III) cyclometalates, [5-(2-MeCB)dfppy]2Ir(LX) (2-MeCB = 2-methyl-o-carboran-1-yl; dfppy = 2-(4,6-difluorophenyl)pyridinato-C2,N; LX = picolinate (5a) or tetrakis(1-pyrazolyl)borate (5b)), with o-carborane at the 5-position of the phenyl ring of the dfppy ligand were prepared to investigate the impact of the o-carborane cage on the blue phosphorescence of complexes. X-ray diffraction analysis of 5a revealed a distorted octahedral coordination geometry around the iridium center with the peripheral carborane substitution of the dfppy ligand. The absorption and emission bands of 5a and 5b were hypsochromically shifted relative to those of the sky blue (dfppy)2Ir(pic) (FIrpic) complex, resulting in deep blue phosphorescence (λ PL = 459 nm for 5a and 452 nm for 5b vs. 468 nm for FIrpic). The complexes showed high to moderate quantum efficiencies in toluene (ΦPL = 0.89 for 5a; 0.47 for 5b) and in PMMA film (ΦPL = 0.45 for 5a; 0.34 for 5b), despite a large decrease in quantum efficiency in THF. A slight decrease in quantum efficiency was observed with increasing doping concentrations of the complexes in PMMA films, indicating suppression of the emission quenching owing to the steric bulkiness of the 2-Me-o-carborane cage. Anodic shifts in the oxidation potentials of 5a and 5b compared with that...
Source: Journal of Organometallic Chemistry - Category: Chemistry Source Type: research

Related Links:

Publication date: Available online 18 November 2019Source: Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of LipidsAuthor(s): Zhen Wang, Hui Gyu Park, Dong Hao Wang, Riki Kitano, Kumar S.D. Kothapalli, J. Thomas BrennaAbstractBranched chain fatty acids (BCFA) and linear chain/normal odd chain fatty acids (n-OCFA) are major fatty acids in human skin lipids, especially sebaceous gland (SG) wax esters. Skin lipids contain variable amounts of monounsaturated BCFA and n-OCFA, in some reports exceeding over 20% of total fatty acids. Fatty acid desaturase 2 (FADS2) codes for a multifunctional enzyme that catalyz...
Source: Biochimica et Biophysica Acta (BBA) Molecular and Cell Biology of Lipids - Category: Lipidology Source Type: research
ConclusionsThe median h-index for an academic thoracic surgeon in Canada and the United States is 10. Surgeons who engage in Twitter activity are more likely to have their research cited by others.
Source: The Annals of Thoracic Surgery - Category: Cardiovascular & Thoracic Surgery Source Type: research
ConclusionsEarly-diastolic phase slope of the HVAD flow waveform might be a novel parameter that can estimate the presence of clinically significant AI.
Source: The Annals of Thoracic Surgery - Category: Cardiovascular & Thoracic Surgery Source Type: research
ConclusionsOnline education for cardiothoracic surgery is seeing increased public use, with high ratings for content and utility. Despite aggressive marketing to STS members, most remain unaware of this website’s existence. Those who are aware approve of its content, but adoption of referring patients to it has been slow. Improved strategies are necessary to make surgeons aware of this STS-provided service and to increase patient referrals to it.
Source: The Annals of Thoracic Surgery - Category: Cardiovascular & Thoracic Surgery Source Type: research
This study evaluated outcomes associated with treatment strategies for this nonagenarian population.MethodsTreatment and overall survival for patients 90 years and older with NSCLC in the National Cancer Data Base (2004-2014) were evaluated using logistic regression, the Kaplan-Meier method, and multivariable Cox proportional hazard models.ResultsThe majority (n = 4152, 57.6%) of the 7205 patients 90 years or older with stage I-IV NSCLC did not receive any therapy. For the entire cohort, receiving treatment was associated with significantly better survival when compared with no therapy (5-year survival, 9.3% [95% confidenc...
Source: The Annals of Thoracic Surgery - Category: Cardiovascular & Thoracic Surgery Source Type: research
ConclusionsThe delay in surgical resection of StageIIIa NSCLC is not associated increased early mortality, however it is associated with worse 3-year post-resection survival.
Source: The Annals of Thoracic Surgery - Category: Cardiovascular & Thoracic Surgery Source Type: research
Publication date: March 2020Source: Interdisciplinary Neurosurgery, Volume 19Author(s): Joel Kaye, Ahmed Meleis, Shabbar Danish, Zhenggang XiongAbstractMeningiomas are relatively slow-growing, typically benign tumors that arise from the arachnoid cells which form the meninges. They are the most common primary brain tumor and account for nearly one-third of all primary brain and spine tumors. Meningiomas can arise from any dural site, however they are infrequently found at the cerebellopontine angle (CPA). While WHO grade I meningiomas are benign and the slowest growing, WHO grade II meningiomas grow significantly faster, d...
Source: Interdisciplinary Neurosurgery - Category: Neurosurgery Source Type: research
We present a case of Moyamoya disease in an infant who presented with neurological symptoms including convulsions and motor deficits. He was misdiagnosed two times and finally investigated in a tertiary hospital with brain computed tomography and magnetic resonance imaging showing affected vessels with typical pattern of Moyamoya diseases in the brain. He underwent surgical intervention and scheduled for follow up.
Source: Interdisciplinary Neurosurgery - Category: Neurosurgery Source Type: research
ConclusionsIn the current series, the factors which were associated with an increased rate of iatrogenic pituitary injury were: increased manipulation of the gland intra-operatively, a firm tumor consistency not amenable to suction or curettage, and larger pituitary adenoma size. Recognition of the heterogeneity of macroadenoma consistency and growth patterns and appropriate usage of intra- and/or extra-capsular tumor resection techniques may help mitigate the risk of surgical pituitary injury.
Source: Interdisciplinary Neurosurgery - Category: Neurosurgery Source Type: research
Conclusion. The hexane extract of L. apiculata leaves showed the lower MIC against S. aureus when compared with extracts obtained from other parts of the plant. The growth curve and the colonies count suggest a bacteriostatic activity of the L. apiculata leaves extract against Staphylococcus aureus. PMID: 31737073 [PubMed]
Source: International Journal of Microbiology - Category: Microbiology Tags: Int J Microbiol Source Type: research
More News: Chemistry