New polymorphic modification of Y, Ho, Tm and Lu tris-2,2,6,6-tetramethyl-heptane-2,4-dionates: Structure, volatility and luminescence

• Published in: Polyhedron 2021-04, Vol.198, p.115077, Article 115077
• Main Authors: Stabnikov, Pavel A., Pervukhina, Natalia V., Kuratieva, Natalia V., Kryuchkova, Natalia A., Korolkov, Ilya V., Urkasym kyzy, Samara, Sysoev, Sergey V., Babailov, Sergey P.
• Format: Article
• Language: English
• Subjects: AIM analysis; Crystal structure; DFT calculations; Ln(III) β-diketonates; Luminescence; NMR; Volatility
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2021.115077

[Display omitted] •It was established a new high-temperature phase Ln(thd)3 (Ln = Y, Ho, Tm, Lu)•For Y(III) complexes with thd-ligands the phase of dimeric molecules is energetically more stable.•The volatility of complexes increases from Yb(thd)3 to Ln(thd)3.•The highest QE of luminescence are obtained for Tb(thd)3 (77%) and Dy(thd)3 (5%). The crystal structure of new isostructural complex Y(thd)3 (I), Ho(thd)3 (II), Tm(thd)3 (III) and Lu(thd)3 (IV) are determined: space group Pna21, Z = 8 (a = 41.956(8) Å, b = 17.837(4) Å, c = 9.742(2) Å, V = 7291(3)Å3 for I; a = 41.778(2) Å, b = 17.8045(6) Å, c = 9.6862(3) Å, V = 7204.9(4)Å3 for II; a = 41.884(5) Å, b = 17.758(2) Å, c = 9.672(1) Å, V = 7193.7(2)Å3 for III,a = 41.942(8) Å, b = 17.712(4) Å, c = 9.711(2) Å, V = 7214(2)Å3 for IV). The crystal structures of I–IV are molecular and consist of discrete monomeric Ln(thd)3 molecules (Ln = Y, Ho, Tm, Lu). The highest quantum yields of luminescence are obtained for Tb(thd)3 (77%), [Tb(thd)3]2 (25%) and Dy(thd)3 (5%), [Dy(thd)3]2 (0.4%). Thermogravimetric investigations show that the volatility of complexes increases from Yb(thd)3 to Pr(thd)3. Melting points of the complexes are close to the known literature data. The complex compounds we synthesized were characterized by NMR in a CDCl3 solution. Quantum chemical calculations are shown that the phase of dimeric molecules is energetically more stable for the Y(III) complexes with thd-ligands.