Dibenzyl isophthalates as versatile hosts in room temperature phosphorescence host–guest systems

We report a series of dibenzyl isophthalates (DBIs) as novel hosts for room-temperature phosphorescence (RTP) host-guest systems, achieving RTP quantum yields (QY) of up to 77% or lifetimes of up to 21.0 s with the guest coronene-<i>d</i> ₁₂. Furthermore, a 4,4'-Br substituted DBI was used to form host-guest RTP systems with 15 different aromatic guest molecules, to tune the phosphorescence emission color from blue to red and to demonstrate the versatility of the host. Mechanistic insights were gained through a host-guest-matrix system which shows RTP by trace combinations of a 4,4'-Br DBI host (0.10 wt%) and a pyrene-<i>d</i> ₁₀ guest (0.01 wt%) in an otherwise non-RTP-emissive aromatic matrix. This work establishes DBIs as readily available and versatile, tunable hosts for RTP host-guest systems, posing an alternative to polymeric hosts.