Syndio-specific polymerization of styrene promoted by rare-earth metal bis(aminobenzyl) complexes bearing pyrrolyl-modified arylamide ligands

Publication date: Available online 15 August 2018Source: Journal of Organometallic ChemistryAuthor(s): Chaopan Wang, Min Li, Zehuai Mou, Yunjie LuoAbstractAcid-base reaction of the rare-earth metal tris(o-dimethylaminobenzyl) complexes Ln (CH2C6H4NMe2-o)3 with 1 equiv. of the pyrrolyl-modified arylamide ligands 2,5-Me2C4H2NSiMe2NHC6H4R (R = H, Cl-p, OMe-p) in toluene gave (2,5-Me2C4H2NSiMe2NC6H5)Ln (CH2C6H4NMe2-o)2 (Ln = Sc (1), Y (2), Lu (3)), (2,5-Me2C4H2NSiMe2NC6H4Cl-p)Y(CH2C6H4NMe2-o)2 (4), and (2,5-Me2C4H2NSiMe2NC6H4OMe-p)Y(CH2C6H4NMe2-o)2 (5) in good isolated yields. These complexes were well-characterized by elemental analysis and NMR spectroscopy. 1, 2 and 4 were structurally determined by single crystal X-ray diffraction. The catalyst systems of 1–5/AliBu3/[Ph3C][B(C6F5)4] were able to promote styrene polymerization to afford pure and highly syndio-tactic polystyrene (rrrr > 99%). Among these rare-earth metal complexes, the complexes with the central metal being the cheapest yttrium showed much higher activity than the expensive scandium analogues. The styrene polymerization catalyzed by 4/AliBu3/[Ph3C][B(C6F5)4] proceeded in a controlled fashion.Graphical abstract
Source: Journal of Organometallic Chemistry - Category: Chemistry Source Type: research

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Conclusions We present a quick, simple, and affordable method to decellularize a muscle flap through the vascular network. Our proposed method is efficient and can be completed in a significantly shorter time when compared with other methods. It is also safe and does not affect integrity of tissue, and this is essential for a reliable recellularization.
Source: Annals of Plastic Surgery - Category: Cosmetic Surgery Tags: Transplantation Surgery and Research Source Type: research
In conclusion, participants suggest that tailored secondary prevention programming that acknowledges and targets the unique exercise, psychological, and peer support needs of patients with SCAD, as well as increased education for healthcare providers, may be integral to promote patients in their recovery.
Source: Canadian Journal of Cardiology - Category: Cardiology Source Type: research
This study presents an exploratory characterization on the effect of build orientation on deformation behavior of Ti–6Al–4V rods produced through electron beam melting (EBM). Microstructural differences in horizontally and vertically printed rods were characterized using optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) coupled with energy dispersive spectroscopy (EDS), and electron backscatter diffraction (EBSD). A typical microstructure of the alloy consists of primary-α and vanadium-enriched β phases. Compared to the horizontal samples, vertically print...
Source: Materials Science and Engineering: A - Category: Materials Science Source Type: research
Publication date: Available online 11 November 2019Source: Materials Science and Engineering: AAuthor(s): Lei Dai, Zhong Liu, Liming Yu, Yongchang Liu, Zengmin ShiAbstractFe–9Cr ODS alloys elaborated by mechanical milling (MM) and followed by hot isostatic pressing (HIP) and hot rolling (HR) have been studied using transmission electron microscopy (TEM) and atom probe tomography (APT) to understand their microstructural characterization. The as-HIP alloy exhibited equiaxed ferrite and contained nanoparticles and low density of dislocations. The as-HR alloy manifested elongated ferrite and contained nanoclusters and h...
Source: Materials Science and Engineering: A - Category: Materials Science Source Type: research
This study investigated microstructure formation as a function of orientation-dependent surface tension anisotropy during directional solidification of Al-4.5%Cu alloy. Axial dendrites (AD), tilted dendrite (TD), and degenerate pattern (DP) were identified in the solidified microstructures of the single crystals. A single-crystal specimen with a stable DP, which was characterized by successive splitting tips, was carefully prepared and specifically investigated. The corresponding mechanical properties were compared with those of single-crystal AD and TD specimens. The ductility and toughness of the single-crystal specimen ...
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Publication date: Available online 11 November 2019Source: Journal of Materials Research and TechnologyAuthor(s): Michelle Souza Oliveira, Fabio da Costa Garcia Filho, Artur Camposo Pereira, Larissa Fernandes Nunes, Fernanda Santos da Luz, Fábio de Oliveira Braga, Henry Alonso Colorado, Sergio Neves MonteiroAbstractThe ballistic performance of multilayered armor system (MAS) with front ceramic tile, followed by a laminate of up to 50 vol.% of fique fabric-reinforced epoxy matrix and back by a 5062H34 aluminum alloy was evaluated. The backface signature (BFS) caused by the bullet in a block of clay witness behin...
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Source: Sensors and Actuators B: Chemical - Category: Chemistry Source Type: research
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