Abstract: A novel organometallic complex that is highly convenient, useful, or reliable, and a light-emitting device are provided. The organometallic complex is represented by General Formula (G2). In General Formula (G2), each of R1 to R6, R8 to R22, and R31 to R34 independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, at least one of R31 to R34 represents an alkyl group having 1 to 10 carbon atoms or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, and n is an integer of 1 to 4.

Abstract: To provide a novel organometallic complex and a novel light-emitting device that are useful or reliable. The organometallic complex includes platinum (Pt), a cyano group, and a phenyl group that has two alkyl groups at the ortho-positions. The light-emitting device includes an organic compound layer held between a pair of electrodes; the organic compound layer includes a light-emitting layer; the light-emitting layer contains an organic compound and the organometallic complex; the organometallic complex includes platinum (Pt), a cyano group, and a phenyl group that has two alkyl groups at the ortho-positions; and the difference between the LUMO level of the organic compound and the HOMO level of the organometallic complex is greater than or equal to 2.5 eV and less than or equal to 3.0 eV.

Abstract: A method for preventing fouling of an electrodialysis membrane when conducting desalting of an inorganic salt-containing aqueous solution containing electrodialysis membrane-fouling substances, which is characterized by adjusting the pH of the solution to the isoelectric points of the fouling substances.