The present invention concerns a metal-carbene complex of the general formula (I) in which R5 and R6 together, or R6 and R7 together, a unit of the formula: in which * denotes the connection to the carbon atoms of the benzene ring bearing the R5 and R6 radicals or R6 and R7 radicals, and the oxygen atom is connected to the carbon atom bearing the R5, R6 or R7 radical, and A is oxygen or sulfur. The present invention further concerns light-emitting layer comprising at least one metal-carbene complex according to the present invention and an organic light-emitting diode comprising a light-emitting layer according to the present invention, a device selected from the group consisting of stationary visual display units, mobile visual display units and illumination means and the use of a metal-carbene complex according to the present invention in organic light-emitting diodes, especially as emitter, matrix material, charge carrier material and charge blocker material.