Nag, Abanti Schmidt, Peter J. Schnick, Wolfgang Synthesis and Characterization of Tb[N(CN)<sub>2</sub>]<sub>3</sub>·2H<sub>2</sub>O and Eu[N(CN)<sub>2</sub>]<sub>3</sub>·2H<sub>2</sub>O:  Two New Luminescent Rare-Earth Dicyanamides Two new rare-earth dicyanamides, namely, Tb[N(CN)<sub>2</sub>]<sub>3</sub>·2H<sub>2</sub>O and Eu[N(CN)<sub>2</sub>]<sub>3</sub>·2H<sub>2</sub>O, have been prepared by ion exchange in aqueous solution, followed by evaporation of the solvent at room temperature. The structures of both compounds have been solved and refined from single-crystal and powder X-ray diffraction data, respectively. The two compounds are isostructural and are built up from irregular quadratic antiprismatic LnN<sub>6</sub>O<sub>2</sub> polyhedra connected to each other by three crystallographically independent dicyanamide ([N(CN)<sub>2</sub>]<sub>3</sub><sup>-</sup>) ions (Tb[N(CN)<sub>2</sub>]<sub>3</sub>·2H<sub>2</sub>O, <i>P</i>2<sub>1</sub>/<i>n</i>,<i> Z</i> = 4, <i>a</i> = 7.4632(15) Å, <i>b</i> = 11.523(2) Å, <i>c</i> = 13.944(3) Å, β = 94.06(3)°, <i>V</i> = 1196.2(4) Å<sup>3</sup>; Eu[N(CN)<sub>2</sub>]<sub>3</sub>·2H<sub>2</sub>O, <i>P</i>2<sub>1</sub>/<i>n</i>,<i> Z</i> = 4, <i>a</i> = 7.4780(3) Å, <i>b</i> = 11.5429(5) Å, <i>c</i> = 13.9756(7) Å, β = 93.998(4)°, <i>V</i> = 1203.41(10) Å<sup>3</sup>). Annealing of the hydrated phases of Ln[N(CN)<sub>2</sub>]<sub>3</sub>·2H<sub>2</sub>O (Ln = Eu, Tb) at 150 °C under an argon atmosphere leads to the formation of nonhydrated Ln[N(CN)<sub>2</sub>]<sub>3</sub> (Ln = Eu, Tb). Both the hydrated (Eu[N(CN)<sub>2</sub>]<sub>3</sub>·2H<sub>2</sub>O) and nonhydrated (Eu[N(CN)<sub>2</sub>]<sub>3</sub>) europium(III) dicyanamides show red luminescence due to the dominant intensity of <sup>5</sup>D<sub>0</sub>−<sup>7</sup>F<i><sub>J</sub></i> (<i>J</i> = 1, 2, 4) emission lines by excitation at 365 nm. The broad excitation band of europium(III) dicyanamide (fwhm = 8000 cm<sup>-1</sup>) ranging between 260 and 420 nm with λ<sub>max</sub> ≈ 30000 cm<sup>-1</sup> is ascribed to a Eu−N charge-transfer transition, which is significantly shifted to lower energy compared to that of oxo compounds due to the nephalauxetic effect. Similarly, both the hydrated (Tb[N(CN)<sub>2</sub>]<sub>3</sub>·2H<sub>2</sub>O) and nonhydrated (Tb[N(CN)<sub>2</sub>]<sub>3</sub>) terbium(III) dicyanamides show green emission at λ<sub>exc</sub> = 365 nm, arising mainly from the dominant <sup>5</sup>D<sub>0</sub>−<sup>7</sup>F<sub>4</sub> transition. However, unlike europium(III) dicyanamide, the broad excitation band of terbium(III) dicyanamide ranging between 250 and 400 nm with a maximum at 33000 cm<sup>-1</sup> can be assigned to the 4f<sup>8</sup>−4f<sup>7</sup>5d<sup>1</sup> transition of Tb<sup>3+</sup>. dicyanamide;nonhydrated;compound;antiprismatic LnN 6O polyhedra;365 nm;transition;Eu;cm;Tb;europium;excitation band 2006-11-28
    https://acs.figshare.com/articles/dataset/Synthesis_and_Characterization_of_Tb_N_CN_sub_2_sub_sub_3_sub_2H_sub_2_sub_O_and_Eu_N_CN_sub_2_sub_sub_3_sub_2H_sub_2_sub_O_Two_New_Luminescent_Rare_Earth_Dicyanamides/3044944
10.1021/cm0607029.s002