Tetraazacyclophanes by Palladium-Catalyzed Aromatic Amination. Geometrically Defined, Stable, High-Spin Diradicals
摘要:
[GRAPHICS]Neutral tetraazacyclophanes were prepared in a one-step palladium-catalyzed amination reaction, Simple oxidation of these materials creates dication diradicals that are stable at room temperature and that are geometrically well defined. The electronic and magnetic properties of the dications were investigated by CV, UV-vis, and EPR spectroscopy. These spectral data and solution phase magnetic susceptibility measurements indicate high spin ground states in certain media. EPR zero field splitting parameters for the diradical suggest that the distance between the two radical sites can be approximated simply by the distance between alternating nitrogens in the macrocycle.
Versatile Direct Cyclization Constructs Spiro‐acridan Derivatives for Highly Efficient TADF emitters
作者:He Liu、Zhiwen Liu、Ganggang Li、Huaina Huang、Changjiang Zhou、Zhiming Wang、Chuluo Yang
DOI:10.1002/anie.202103187
日期:2021.5.25
provide a wide possibility to assemble efficient TADF emitters. As an example, D2T‐TR with high photoluminescent quantum yield and proper TADF character is applied in organic lightemitting diodes (OLEDs) which achieves a maximum external quantum efficiency (EQE) of 27.1 %. This work shows us a bright inspiration on developing excellent organic optoelectronic materials and an effective tool to realize it
The present invention provides a novel polycyclic aromatic compound having a plurality of aromatic rings linked by a boron atom, a nitrogen atom, and the like, and thus increases the number of alternatives of a material for an organic electroluminescent (EL) device. Furthermore, the present invention provides an excellent organic EL device by using a novel polycyclic aromatic compound as a material for an organic EL device.
Process for preparing aqueous dispersions of acrylic-urethane graft copolymers
申请人:Polyvinyl Chemie Holland B.V.
公开号:EP0167188A1
公开(公告)日:1986-01-08
Ethylenically unsaturated aqueous urethane dispersions of controlled molecular weight are prepared by first reacting an active hydrogen atom containing polymerizable vinyl compound with a diisocyanate.
The adduct thus formed. being a nearly selectively made mono-ethylenically unsaturated mono-isocyanate compound, is used in preparing an aqueous urethane polymer dispersion by reacting this adduct with polyisocyanates, organic compounds containing active hydrogen atoms like polyols and polyamines and organic compounds containing at least one active hydrogen atom and at least one group capable of saltformation. foiiowed by neutralizing, dispersing in water ano chain-extending the prepolymer.
This ethyienically unsaturated aqueous urethane polymer dispersion is subjected to an emulsionpolymerization by conventional techniques with acrylate, methacrylate and related polymerizable compounds, yielding an aqueous dispersion of an urethane-acrylate graft copolymer.
These urethane-acrylate graft copolymers are particularly useful as binders for coatings, printing inks and related applications.
Disclosed is an aqueous coating composition which keeps in high nonvolatile contents during coating operation and capable of being effectively applied even under a relatively high humidity condition. The coating composition imparts high orientation of metallic pigment particles to the cured film. The aqueous coating composition of the present invention comprises a specific acryl polymer varnish (a) and a specific urethane oligomer dispersion.