Ligands containing the {O=P} donor moiety are of paramount importance in the sensitization of Mn(ll) luminescence [1]. Besides mono- and polydentate phosphine oxides, ligands based on the phosphoramide skeleton revealed to be suitable for the preparation of luminescent Mn(II) complexes [2,3], and it was observed an improvement of the luminescence on increasing the light harvesting features of the substituents on the ligands. A potential fragment able to efficiently absorb UV radiation is the carbazolyl moiety. The phosphoramide N,N,N',N'-tetramethyl-P-carbazol-9-ylphosphonic diamide (L) was successfully coordinated to MnX2 halides (X = Cl, Br, I), obtaining tetrahedral complexes having generai formula [MnX2L2]. The structures were ascertained by means of single-crystal X-ray diffraction. The three complexes showed noticeable luminescence in the green region upon excitation with UV radiation, attributed to the Mn(II) 4T1(4G)-GA1(6S) transition. The luminescence lifetimes are strongly dependent upon the choice of the coordinated halide.
Carbazolyl-substituted phosphoramides as ligands for Mn(II) luminescent complexes
Valentina Ferraro
2022-01-01
Abstract
Ligands containing the {O=P} donor moiety are of paramount importance in the sensitization of Mn(ll) luminescence [1]. Besides mono- and polydentate phosphine oxides, ligands based on the phosphoramide skeleton revealed to be suitable for the preparation of luminescent Mn(II) complexes [2,3], and it was observed an improvement of the luminescence on increasing the light harvesting features of the substituents on the ligands. A potential fragment able to efficiently absorb UV radiation is the carbazolyl moiety. The phosphoramide N,N,N',N'-tetramethyl-P-carbazol-9-ylphosphonic diamide (L) was successfully coordinated to MnX2 halides (X = Cl, Br, I), obtaining tetrahedral complexes having generai formula [MnX2L2]. The structures were ascertained by means of single-crystal X-ray diffraction. The three complexes showed noticeable luminescence in the green region upon excitation with UV radiation, attributed to the Mn(II) 4T1(4G)-GA1(6S) transition. The luminescence lifetimes are strongly dependent upon the choice of the coordinated halide.Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
