We report a comparative study of coordination behaviour of 2-(2-aminophenyl)benzothiazole (NH
2-
pbt) and its phosphorus-containing derivative, α-aminophosphine oxide (PCNH-
pbt), towards zinc halides. The corresponding coordination compounds [Zn(L)
2Hal
2] (L = PCNH-
pbt, Hal =
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We report a comparative study of coordination behaviour of 2-(2-aminophenyl)benzothiazole (NH
2-
pbt) and its phosphorus-containing derivative, α-aminophosphine oxide (PCNH-
pbt), towards zinc halides. The corresponding coordination compounds [Zn(L)
2Hal
2] (L = PCNH-
pbt, Hal = Cl,
1 and Hal = Br,
2) and [Zn(L’)Hal
2] (L’ = NH
2-
pbt, Hal = Cl,
3 and Hal = Br,
4) were obtained as single phases. As evidenced by single-crystal X-ray diffraction analysis, L’ ligand coordinates to Zn in a chelate manner via two N atoms. Despite a similar coordination mode in complexes
3 and
4, the spatial geometry of the ligand differs notably, which implies a relatively high flexibility of NH
2-
pbt. The L ligand exhibits another coordination mode, binding with Zn only via the oxygen of the P=O group. The differences in the structures of NH
2-
pbt,
3 and
4, and their counterparts, PCNH-
pbt,
1 and
2, induce differences in their solid-state photoluminescence properties. The former group of the compounds exhibits conventional single-band emission, while the latter group reveals two bands. The minor band at 450 nm is ascribed to a radiative transition for the regular amine species, while the major band at 520–550 nm can be associated either with the proton-transferred imine species (ESIPT mechanism) or with a charge transfer state (TICT) with a different geometry.
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