| Summary: | Photophysical properties of two Re(I) complexes [ReCl(CO)<sub>3</sub>(R-C<sub>6</sub>H<sub>4</sub>-terpy-κ<sup>2</sup>N)] with remote amine groups, <i>N</i>-methyl-piperazinyl (<b>1</b>) and (2-cyanoethyl)methylamine (<b>2</b>), were investigated. The complexes show strong absorption in the visible region corresponding to metal-to-ligand charge transfer (<sup>1</sup>MLCT) and intraligand-charge-transfer (<sup>1</sup>ILCT) transitions. The energy levels of <sup>3</sup>MLCT and <sup>3</sup>ILCT excited-states, and thus photoluminescence properties of <b>1</b> and <b>2</b>, were found to be strongly affected by the solvent polarity. Compared to the parent chromophore [ReCl(CO)<sub>3</sub>(C<sub>6</sub>H<sub>5</sub>-terpy-κ<sup>2</sup>N)] (<b>3</b>), both designed complexes show significantly prolonged (by 1–2 orders of magnitude) phosphorescence lifetimes in acetonitrile and dimethylformamide, contrary to their lifetimes in less polar chloroform and tetrahydrofuran, which are comparable to those for <b>3</b>. The femtosecond transient absorption (fsTA) measurements confirmed the interconversion between the <sup>3</sup>MLCT and <sup>3</sup>ILCT excited-states in polar solvents. In contrast, the emissive state of <b>1</b> and <b>2</b> in less polar environments is of predominant <sup>3</sup>MLCT nature.
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