Excited-state intramolecular proton transfer with and without the assistance of vibronic-transition-induced skeletal deformation in phenol–quinoline

Skeletal deformation motion is demonstrated from the specific vibronic excitation of phenol–quinoline molecules.

Polymethine dyes

There are a lot of different dye classes with complete different chemical structures. On the basis of a common classification the term “polymethine dyes” was created in 1926. Common criteria are a conjugated polymethine chain with terminal functional groups and an odd number 2n + 3 of π-centers and 2n + 4 π-electrons (n is the number of vinyl groups), the vinylene shift of the 0–0 vibronic transition of about 100 nm per vinyl group, the influence of substituents or heteroatoms according to Dewar´s Rules and a bathochromic shift by twisting of the polymethine chain according to the Brunings–Corwin effect.

Narrow-band red-emitting KZnF3:Mn4+ fluoroperovskites: insights into electronic/vibronic transition and thermal quenching behavior

An in-depth study on a new red-emitting KZnF3:Mn4+ fluoroperovskite reveals the electronic/vibronic transition, the local coordination environment, the multiple crystallographic site occupation, and the thermal quenching behavior, of Mn4+.