Extraction and coordination studies of a carbonyl–phosphine oxide scorpionate ligand with uranyl and lanthanide(iii) nitrates: structural, spectroscopic and DFT characterization of the complexes

Abstract

Hybrid scorpionate ligand (OPPh2)2CHCH2C(O)Me (L) was synthesized and characterized by spectroscopic methods and X-ray diffraction. The selected coordination chemistry of L with UO2(NO3)2 and Ln(NO3)3 (Ln = La, Nd, Lu) has been evaluated. The isolated mono- and binuclear complexes, namely, [UO2(NO3)2L] (1), [{UO2(NO3)L}2(μ2-O2)]·EtOH (2), [La(NO3)3L2]·2.33MeCN (3), [Nd(NO3)3L2]·3MeCN (4), [Nd(NO3)2L2]+·(NO3)−·EtOH (5) and [Lu(NO3)3L2] (6) have been characterized by IR spectroscopy and elemental analysis. Single-crystal X-ray structures have been determined for complexes 1-5. Intramolecular intraligand π-stacking interactions between two phenyl fragments of the coordinated ligand(s) were observed in all complexes 1-5. The π-stacking interaction energy was estimated from Bader's AIM theory calculations performed at the DFT level. Solution properties have been examined using IR and multinuclear ((1)H, (13)C, and (31)P) NMR spectroscopy in CD3CN and CDCl3. Coordination modes of L vary with the coordination polyhedron of the metal and solvent nature showing many coordination modes: P(O),P(O), P(O),P(O),C(O), P(O),C(O), and P(O). Preliminary extraction studies of U(VI) and Ln(III) (Ln = La, Nd, Ho, Yb) from 3.75 M HNO3 into CHCl3 show that scorpionate L extracts f-block elements (especially uranium) better than its unmodified prototype (OPPh2)2CH2.

Lanthanide phosphine oxide complexes

“…Heating the complexes in the solid state leads to ligand redistribution reactions which give yellow [Ln(NO 3 ) (19) 3 ](NO 3 ) 2 which were structurally characterised for Ln = Gd, Yb. The structures Ln(NO 3 ) 3 complexes of (Ph 2 P(O)) 2 CHCH 2 COMe, (20), have been determined and show [Ln(NO 3 ) 3 (20) 2 ] (Ln = La, Nd) to be isostructural with bidentate nitrates and(20)bonding through the phosphoryl oxygen atoms only[84]. Ionic complexes analogous to those formed by(19) were crystallised from ethanol as [Nd(NO 3 ) 2 (20) 2 ]NO 3 ÁEtOH.…”

Highly photo- and triboluminescent lanthanide(iii) coordination polymers based on diphosphine dioxides containing azaheterocyclic linkers

“…Yield: 0.120 g (77%). 31 P{ 1 H} NMR d (202.47 MHz, CDCl 3 ) 20.02, 16.96. 1 H NMR (500 MHz, CDCl 3 ) d 9.20-9.09 (m, 1H), 8.31 (q, J = 4.7 Hz, 1H), 7.69 (ddd, J = 20.9, 12.2, 7.4 Hz, 8H), 7.55 (q, J = 7.3 Hz, 4H), 7.44-7.32 (m, 8H).…”

“…Multidentate phosphine oxide ligands have been previously studied as selective extractants of Ln 3+ ions. [31][32][33] Recently, diphosphine dioxides have been increasingly used for the construction of coordination compounds with outstanding luminescence properties. 13,22,25,30,[34][35][36][37][38][39][40][41][42][43] Most diphosphine dioxides used for preparing lanthanide complexes contain linkers that are not involved in coordination to the Ln 3+ ion.…”

“…Multidentate phosphine oxide ligands have been previously studied as selective extractants of Ln 3+ ions. 31–33 Recently, diphosphine dioxides have been increasingly used for the construction of coordination compounds with outstanding luminescence properties. 13,22,25,30,34–43…”

Multifunctional Inorganic‐Organic U‐MOF Materials with Nitrogen Heterocyclic Carboxylate: Synthesis, Structure and Properties

“…It has been an active area of exploration on uranyl complexes since the suitable starting materials were discovered. [1,2] The uranium, as a good candidate element for mixed organicinorganic extended networks complexes has novel chemical compositions and physicochemical properties, [3][4][5][6][7] such as biomedical imaging, [8,9] luminescence sensors [10] and sensors over light-emitting devices (LEDs, OLEDs). [11,12] ion exchange, [13] proton conductivity, [14] intercalation chemistry, [15] photochemistry, [16] nonlinear optics, [17] selective oxidation catalysis, nuclear power, [18] X-ray attenuation and detection [19,20] and so on.…”