Esters containing aromatic groups as solvents for organic electronic formulations

A formulation comprising

• (A) at least one ester solvent according to General Formula (II):
• wherein R1 is H or R3;
• R2 is H or R3;
• and R3 may be the same or different from each other and is on each occasion selected independently from the group consisting of hydrogen, straight-chain alkyl groups having from 1 to 12 carbon atoms, straight-chain alkenyl or alkynyl groups having from 2 to 12 carbon atoms, branched-chain alkyl or alkenyl groups having from 3 to 12 carbon atoms and branched-chain alkynyl groups having from 4 to 12 carbon atoms, wherein one or more non-adjacent CH2 groups may be optionally replaced by —O—, —S—, or —Si(R5)2—, or
• R1 and R2 taken together represent=CH2;
• and R3 is selected from the group consisting of hydrogen, straight-chain alkyl groups having from 1 to 12 carbon atoms, straight-chain alkenyl or alkynyl groups having from 2 to 12 carbon atoms, branched-chain alkyl or alkenyl groups having from 3 to 12 carbon atoms and branched-chain alkynyl groups having from 4 to 12 carbon atoms, wherein one or more non-adjacent CH2 groups may be optionally replaced by —O—, —S—, or —Si(R5)2—;
• and
• wherein X on each occasion is selected independently from N or CR4 with the provision that no more than three X are selected as N;
• R4 on each occasion is selected independently from the group consisting of hydrogen, straight-chain alkyl or alkoxy groups having from 1 to 12 carbon atoms, straight-chain alkenyl or alkynyl groups having from 2 to 12 carbon atoms, branched-chain alkyl, alkoxy or alkenyl groups having from 3 to 12 carbon atoms, branched-chain alkynyl groups having from 4 to 12 carbon atoms and SiR53;
• R5 on each occasion is selected independently from the group consisting of hydrogen, straight-chain alkyl or alkoxy groups having from 1 to 12 carbon atoms and branched-chain alkyl or alkoxy groups having from 3 to 12 carbon atoms;
• Q2 is absent;
• and
• wherein at least one R4 is a straight-chain alkoxy group having from 1 to 12 carbon atoms or a branched-chain alkoxy group having from 3 to 12 carbon atoms;
• and
• (B) at least one organic functional material is selected from the group consisting of fluorescent emitters, phosphorescent emitters, host materials, matrix materials, exciton-blocking materials, electron-transport materials, electron-injection materials, hole-transport materials, hole-injection materials, n-dopants, p-dopants, wide-band-gap materials, electron-blocking materials and hole-blocking materials.