3D-supermolecular structure and electronic absorption of uranyl β-diketone [UO 2(tfa) 2(L)] (L = H 2O, OHCH 2CH 3) complex

• Published in: Journal of molecular structure Vol. 997; no. 1; pp. 1 - 6
• Main Authors: Al-Anber, Mohammed A., Daoud, Haneen M., Rüffer, Tobias, Lang, Heinrich
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2011
• Subjects: absorption; Butanedione; crystals; ethanol; hydrogen; Hydrogen bond; oxygen; Supramolecular; Uranyl ion; X-radiation; β-diketone; π–π interaction; Uranyl ion; Supramolecular; Butanedione; β-diketone; π–π interaction; Hydrogen bond
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2011.03.040

► The reaction of UO 2 2 + ion with 4,4,4,-trifluoro-1-(2-furyl)-1,3-butanedione yielded a mononuclear [UO 2(tfa) 2(H 2O)] (3) complex. ► The electronic absorption for 3 shows LMCT (384 nm (<10)), wherein the U(VI) center is only capable to function as acceptor site. ► Dissolving 3 in ethanol gave a single crystals of 3D-supramilecular polymer of [UO 2(tfa) 2(HOCH 2CH 3)] n ( 4). Uranyl β-diketone complex UO 2(tfa) 2·H 2O ( 3) (tfa = deprotonated 4,4,4,-trifluoro-1-(2-furyl)-1,3-butanedione) has been successfully prepared by reacting UO 2(OAc) 2·2H 2O (OAc = O 2CMe) with two equivalents of 4,4,4,-trifluoro-1-(2-furyl)-1,3-butanedione ( H-tfa: 1) in ethanol. Complex 3 was characterized by elemental analysis and FT-IR. Dissolving 3 in ethanol gave during several days single crystals of [UO 2(tfa) 2(OHCH 2CH 3)] ( 4), wherein one ethanol molecule replaces aqua ligand. The solid-state structure of 4 was determined by a single X-ray analysis. Crystal data of C 18H 14F 6O 9U: a = 13.7163(7), b = 20.7528(10), c = 7.4664(4) Å, β = 90.818(4)°, space group P2(1)/c, Z = 4 and d calc = 2.270 mg/m 3. Complex 4 adopted a distorted pentagonal bipyramidal geometry. The coordinated oxygen atoms of tfa ( deprotonated- 1) ligands are occupying equatorial positions, while the oxygen atoms of UO 2 2 + are still in the axial positions. The formation of the π–π interactions together with hydrogen bonded result in the set up a 3D-supramolecular architecture. The electronic absorption of 3 is reported and discussed.