An organic light-emitting medium including a pyrene derivative represented by the following formula (1) and a phenyl-substituted anthracene derivative represented by the following formula (2):

##STR00001##

wherein Ar.sup.1 to Ar.sup.4 are independently a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 5 to 20 ring atoms.

An organic light-emitting medium including a pyrene derivative represented by the following formula (1) and a phenyl-substituted anthracene derivative represented by the following formula (2):

##STR00001##

wherein Ar.sup.1 to Ar.sup.4 are independently a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 5 to 20 ring atoms.

A method for reducing the mutagenicity of polycyclic aromatic compounds (PAC's) having one or more bay regions which involves alkylating the PAC's with an alkylating agent in the presence of a catalyst to lower the mutagenicity down to as much as about 0.1. The resulting alkylated polycyclic aromatic compounds retain their physical and chemical properties for safe industrial use including as rubber processing oils, inks, etc.

A method for reducing the mutagenicity of polycyclic aromatic compounds (PAC's) having one or more bay regions which involves alkylating the PAC's with an alkylating agent in the presence of a catalyst to lower the mutagenicity down to as much as about 0.1. The resulting alkylated polycyclic aromatic compounds retain their physical and chemical properties for safe industrial use including as rubber processing oils, inks, etc.

An organic light-emitting medium including a pyrene derivative represented by the following formula (1) and a phenyl-substituted anthracene derivative represented by the following formula (2): ##STR00001##
wherein Ar.sup.1 to Ar.sup.4 are independently a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 5 to 20 ring atoms.

An organic light-emitting medium including a pyrene derivative represented by the following formula (1) and a phenyl-substituted anthracene derivative represented by the following formula (2): ##STR00001##
wherein Ar.sup.1 to Ar.sup.4 are independently a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 5 to 20 ring atoms.

Disclosed herein are graphene nanoribbons, controllable and reproducible methods of synthesizing graphene nanoribbons, and uses thereof. Transistors containing graphene nanoribbons are also disclosed.

Disclosed herein are graphene nanoribbons, controllable and reproducible methods of synthesizing graphene nanoribbons, and uses thereof. Transistors containing graphene nanoribbons are also disclosed.

New methods for preparing bridged bi-aromatic ligands are disclosed. The methods employ aryl coupling of unprotected phenols. The ligands may be used to prepare transition metal compounds useful as catalysts in olefin polymerization.

New methods for preparing bridged bi-aromatic ligands are disclosed. The methods employ aryl coupling of unprotected phenols. The ligands may be used to prepare transition metal compounds useful as catalysts in olefin polymerization.