Photonics of coordination complexes of dipyrrins with p- and d-block elements for application in optical devices

In the present paper spectral–luminescent, lasing, photochemical, sensory, and photosensitized characteristics of a number of Zn(II) and B(III) coordination complexes of dipyrrins with different structures are investigated. The results show that alkyl-, phenyl-, and propargylamino-derivatives of dipyrrin core in these complexes have excellent luminescent characteristics and can be used as active media for tunable liquid and solid-state lasers. Zinc (Zn-dpm 2 ) and boron fluoride complexes of dipyrrins (BODIPYs) with halogen atoms and aza-substitution in meso- position in their ligands do not exhibit effective fluorescence, but some of them have long-lived emission due to increased nonradiative intersystem processes in an excited state proceeding by the mechanism of heavy atom and the presence of low-lying nπ- and σπ-states of different natures and multiplicities. The reason for the short-wavelength shift of the Zn-dpm 2 spectra compared to the corresponding BODIPY is studied using quantum-chemical calculation. For solid samples based on halogenated complexes, a dependence of the long-lived emission intensity on the oxygen concentration in the surrounding gas mixture is established that indicates the possibility of application of these complexes for the creation of optical oxygen sensors. Moreover, results of investigations of halogen-substituted tetraphenyl-aza-BODIPY complexes as photosensitizers of singlet oxygen production are presented. Such complexes are promising for creating media for generation of singlet oxygen, which is important for photodynamic therapy and oxidation catalysis. In addition, data on the stability of these compounds in different electronic states are presented.