NOVELTY - Ruthenium carbene complexes (I) are new.    USE - (I) are useful in device, which is consumer product or organic light emitting device (all claimed), where the consumer product includes flat panel displays, computer monitors, televisions, billboards, lights for interior or exterior illumination and/or signaling, heads up displays, fully transparent displays, flexible displays, laser printers, telephones, cell phones, personal digital assistants (PDAs), laptop computers, digital cameras, camcorders, viewfinders, micro-displays, vehicles, a large area wall, theater or stadium. (I) are useful in optoelectronic devices, which are organic solar cells and organic photodetectors, and organic devices, which is an organic transistor.    DETAILED DESCRIPTION - Ruthenium carbene complexes of formula (I) are new.    L1-L2=bidentate ligand a -1 charge, where auxiliary ligand has structure of formula (B1-Y1-C(((G) n)-C(Z-B4)(B3)) (B2)) bears no charge, the metal complex has an overall 0 charge, and the ring B5 is connected to the Ru through a carbene bond;    Ru=+2 charge;    ring A=aryl comprising 5- or 6-membered carbocyclic or heterocyclic group;    a, b=0-4;    X1=N-R1a, O or S;    X2=C or N;    R1A, R1B, R1a=H, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl and/or phosphino, where R1A each is optionally linked to form a ring fused A, R1B is optionally linked to form a ring fused to ring B5 and the fused ring is optionally substituted;    Y1, Z=C, N or P; either    B1-B4=H, deuterium, halide, alkyl,cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy,amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids,ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl and/or phosphino; or    B1B2, B3B4=5- or 6-membered cyclic group having 0-4 ring heteroatoms or 8-10-membered fused bicyclic group having 0-4 ring heteroatoms,optionally substituted with one or more substituents of H, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy,amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl,aryl, heteroaryl, acyl, carbonyl, carboxylic acids,ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl and/or phosphino;    G=alkyl or 1-5C alkenyl, where first end of G is bonded to Y1 or B2, and a second end of G is bonded to Z or B3; and    n=0 or 1.    Provided that when n is 0, G is absent. An INDEPENDENT CLAIM is included for a first device comprising an organic light emitting device, further comprising an anode (120); a cathode (160), and organic layer, disposed between the anode and the cathode, comprising (I).    DESCRIPTION OF DRAWING(S) - The figure shows cross-sectional view of organic light emitting device.    Substrate (110)    Anode (115)    Hole injection layer (120)    Hole transport layer (125)    Cathode. (160)