Electroluminescent material and device thereof

A metal complex, comprising a metal M and a ligand La coordinated with the metal M, wherein the metal M is selected from metals having a relative atomic mass greater than 40, and the ligand La has a structure represented by Formula 1:

• wherein
• Z1 and Z2 are each independently selected from C or N, and Z1 and Z2 are different;
• W is, at each occurrence identically or differently, selected from B, N or P;
• ring A, ring C, and ring D are, at each occurrence identically or differently, selected from a five-membered unsaturated carbocyclic ring, an aromatic ring having 6 to 30 carbon atoms or a heteroaromatic ring having 3 to 30 carbon atoms;
• ring B is selected from a hetero ring having 5 to 30 ring atoms;
• Ra, Rb, Rc, and Rd represent, at each occurrence identically or differently, mono-substitution, multiple substitutions or non-substitution;
• Ra, Rb, Rc, and Rd are, at each occurrence identically or differently, selected from the group consisting of:
• hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted arylalkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermanyl having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a sulfanyl group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;
• adjacent substituents Ra, Rb, Rc, and Rd can be optionally joined to form a ring.