Аннотация:The principles of the “multiphotonic emission”, i.e. multiple emission from one lanthanide ion, in heterometallic lanthanide terephthalates were determined. Thanks to it, another system with the same effect, namely EuxY1-x(dbm)3(Phen) (Hdbm – dibenzoylmethanate, Phen – o-phenanthroline) was found. The criteria for concentration quenching appearance were formulated and demonstrated.