Organic compound and organic light emission device

An organic compound having a lone electron-pair and a π electron orbit, wherein:

• said organic compound is a heptazine derivative that is represented by Formula (1) below and that has three arbitrary substituents R1, R2, and R3 which are independent of each other;
• and
• the substituents R1, R2, and R3 are constituted by two types or three types of substituents.

An organic light emitting device, comprising a luminescent layer that contains a dopant compound and a host compound,

• the host compound being an organic compound which has a lone electron-pair and a π electron orbit and in which an energy gap ΔEST obtained by subtracting an energy level ET1 of a lowest triplet excitation state T1 from an energy level ES1 of a lowest singlet excitation mode S1 is negative or 0 eV≤ΔEST<0.0090 eV.

An organic light emitting device comprising a luminescent layer containing a dopant compound and a host compound,

• the host compound being a heptazine derivative that has a lone electron-pair and a 7E electron orbit, that is represented by Formula (1) below, and that includes an arbitrary substituent R1.