Christopher L Cahill

• Doctor of Philosophy
• Chair at George Washington University

A series of compounds of the form [HAr]2[UO2X4] is reported here, wherein Ar is systematically varied between pyridine (1‐X), quinoline (2‐X), acridine (3‐X), 2,5‐dimethylpyrazine (4‐X), quinoxaline (5‐X), and phenazine (6‐X), and X=Cl or Br. With greater conjugation in the organic cation, a larger quenching in uranyl luminescence is observed in th...

A series of compounds of the form [HAr]2[UO2X4] is reported here, wherein Ar is systematically varied between pyridine (1‐X), quinoline (2‐X), acridine (3‐X), 2,5‐dimethylpyrazine (4‐X), quinoxaline (5‐X), and phenazine (6‐X), and X = Cl or Br. With greater conjugation in the organic cation, a larger quenching in uranyl luminescence is observed in...

Since their discovery in 1966, scorpionate ligands have been utilized to make coordination compounds for a variety of applications such as: studying organometallic reactions, biomimetic complexes, light-emitting materials and single-ion magnets. The recent development of a solvent-free pyrazole substitution chemistry has yielded the quantitative sy...

We report the synthesis, crystal structures, photophysical and magnetic properties of 11 novel lanthanide complexes with the asymmetrically functionalized trispyrazolylborate ligand 4-nitrotrispyrazolylborate, 4-NO2Tp-: [Ln(4-NO2Tp)3] (Ln = La-Dy, except Pm). In-depth photophysical characterization of the ligands via luminescence, reflectance and a...

Halide perovskites provide a versatile platform for exploring the effect of non-covalent interactions, including halogen bonding, on material properties such as band gap, luminescence, and frontier orbital landscape. Herein we report six new zero-dimensional tellurium iodide perovskite derivatives, consisting of [TeI6]2- octahedra charge balanced b...

We report the synthesis, crystal structures, photophysical and magnetic properties of 11 novel lanthanide complexes with the asymmetrically functionalized trispyrazolylborate ligand, 4-nitrotrispyrazolylborate, 4-NO2Tp–: [Ln(4-NO2Tp)3] (Ln = La – Dy, except Pm). In depth photophysical characterization of the ligands via luminescence, reflectance an...

A 1:1 reaction pot of lanthanide(III):1,3,5-benzenetrisbenzoate (Ln(III):BTB) in a 2:1 mixture of DMF/H2O was subject to solvothermal and sonochemical conditions in order to form new Ln-BTB polymorphs. Solvothermal crystal growth is time dependent, yielding a new MOF structure Nd4(BTB)4(H2O)10•(H2O)7 (1) after 1-2 days and two new analogues of Ln(B...

We report the synthesis of five new hybrid materials containing the [PuCl6]2- anion and charge-balancing, noncovalent interaction donating 4-X-pyridinium (X = H, Cl, Br, I) cations. Single crystals of the title compounds were grown and harvested from acidic, chloride-rich, aqueous media, and their structures were determined via X-ray diffraction. C...

Twelve novel Ag+/UO22+ heterometallic complexes have been prepared and characterized via structural, spectroscopic, and computational methods to probe the effects of Ag-oxo interactions on bonding and photophysical properties of the uranyl cation. Structural characterization reveals Ag-oxo interaction distances ranging from 2.475(3) Å to 4.287(4) Å...

Reported is a series of eight antimony halide perovskite derivatives synthesized from acidic aqueous solutions of antimony oxide and halogen substituted pyridines. These materials feature anionic one-dimensional antimony halide (SbX; X = Cl, Br, I) chains or ribbons charge-balanced by organic para-halopyridinium cations (XPy; X = H, Cl, Br) which a...

Reported are the syntheses and characterization of six new heterometallic UO22+/Pb2+ compounds. These materials feature rare instances of M-oxo interactions, which influence the bonding properties of the uranyl cation. The spectroscopic effects of these interactions were measured using luminescence and Raman spectroscopy. Computational density func...

Reported are the syntheses, structural characterizations and luminescence properties of three novel [UO2Cl4]2 bearing compounds containing substituted 1,1’-dialkyl-4,4’-bipyridinum dications (i.e. viologens). These compounds undergo photoinduced luminescence quenching upon exposure to UV radiation. Kinetic analyses indicate the degree of quenching...

Reported are the syntheses, structural characterizations and luminescence properties of three novel [UO2Cl4]2 bearing compounds containing substituted 1,1’-dialkyl-4,4’-bipyridinum dications (i.e. viologens). These compounds undergo photoinduced luminescence quenching upon exposure to UV radiation. Kinetic analyses indicate the degree of quenching...

Reported are the syntheses and characterization of six new heterometallic UO22+/Pb2+ compounds. These materials feature rare instances of M-oxo interactions, which influence bonding properties of the uranyl cation. The spectroscopic effects of these interactions were measured using diffuse reflectance, luminescence and Raman spectroscopy. Computati...

Reported are the syntheses and characterization of six new heterometallic UO22+/Pb2+ compounds. These materials feature rare instances of M-oxo interactions, which influence bonding properties of the uranyl cation. The spectroscopic effects of these interactions were measured using diffuse reflectance, luminescence and Raman spectroscopy. Computati...

Reported are the synthesis, crystal structures and photophysical properties of twenty-eight, novel lanthanide compounds across five structural types, [Ln(3-NO2Tp)2(NO3)] (1-Ln, Ln = La – Tm, except Pm), [Bu4N][Ln(3-NO2Tp)(NO3)3] (2-Ln, Ln = Yb, Lu), [Eu(3-NO2Tp)2Cl(H2O)]·2iPrOH (3-Eu), [{Ln(3-NO2Tp)2}2(μ2-CO3)] (4-Ln, Ln = La – Gd, except Pm) and [...

Reported is the high-pressure structural and optical characterization of a chloroindium(III) hybrid perovskite consisting of isolated anionic [In2Cl10]⁴⁻ dimers charge balanced by 4-iodopyridinium cations. No phase transitions were observed upon compression between 0 and 1.51 GPa. The metal-halide bond lengths of the dimers decrease slightly, resul...

Reported is the synthesis characterization of eight new halotellurate(IV) compounds consisting of isolated [TeX6]2- (X = Cl, Br) octahedra charge balanced by halopyridinium (XPy; X = H, Cl, Br, I) cations and assembled via non-covalent interactions (NCIs) in the second coordination sphere. Computational density functional theory (DFT) based natural...

The phenomenon of quantum confinement in hybrid low-dimensional lead-free perovskite derivatives continues to hinder the development of these materials for electron carrier devices such as next generation solar cells. Spatial separation of metal-halide octahedra within crystal structures yields materials with greater moisture and photodegradation r...

Correction for ‘An exploration of homo- and heterometallic UO 2 ²⁺ hybrid materials containing chelidamic acid: synthesis, structure, and luminescence studies’ by Paula M. Cantos et al. , CrystEngComm , 2013, 15 , 9039–9051, DOI: 10.1039/C3CE41655K.

The synthesis, structure, and spectroscopic characterization (luminescence, Raman, IR, and solid-state UV-Vis) of five new uranyl (UO22+) complexes containing 2,2’-bipyridine and either benzoic acid (1), 4-fluorobenzoic acid (2), 4-chlorobenzoic acid (3), 4-bromobenzoic acid (4), and 4-iodobenzoic acid (5) are described. Single crystal X-ray diffra...

The synthesis, structure, and spectroscopic characterization of the first transplutonium metal–organic framework (MOF) is described. The preparation and structure of Am‐GWMOF‐6, [Am2(C6H8O4)3(H2O)2][(C10H8N2)], is analogous to that of the isostructural trivalent lanthanide‐only containing material GWMOF‐6. The presented MOF architecture is used as...

The synthesis, structural, and spectroscopic characterization of the first transplutonium metal‐organic framework (MOF) is described. The preparation and structure of Am‐GWMOF‐6, [Am2(C6H8O4)3(H2O)2][(C10H8N2)], is analogous to that of the isostructural trivalent lanthanide‐only containing material GWMOF‐6. The presented MOF architecture is used as...

https://pubs.acs.org/toc/inocaj/58/11

The hydrothermal reaction of the uranyl cation, copper(II), and trans-3,3(pyridyal)acrylic acid (T33PA) has yielded two new bimetallic uranyl containing coordination polymers, (UO2)2(C8H6O2N)6Cu (1) and [(UO2)2(O)(H2O)(C8H6O2N)3CuCl]·H2O (2). Herein we discuss the synthesis, structure, and luminescent properties of the 2D compounds 1 and 2, both of...

A new thorium metal‐organic framework (MOF), Th(OBA)2, where OBA is 4,4′‐oxybis(benzoic) acid, has been synthesized hydrothermally in the presence of a range of nitrogen‐donor coordination modulators. This Th‐MOF, described herein as GWMOF‐13, has been characterized by single‐crystal and powder X‐ray diffraction, as well as through a range of techn...

Six new uranyl hybrid materials have been synthesized solvothermally utilizing the ligands 2,2′-bipyridine-3,3′-dicarboxylic acid (H 2 L) and 2,2′:6′,2′′-terpyridine (TPY). The six compounds are classified as either molecular complexes (I 0 O 0 connectivity), [ 3 ]·9H 2 O (6). A discussion of the influence of transition metal incorporation, chelati...

Two series of lanthanide metal-organic frameworks (MOFs) formulated as {Ln2(TBrTA)3(H2O)8•2H2O}n [Ln = La (1), Ce (2), Pr (3), Nd (4), Sm (5), Eu (6), Gd (7), Tb (8), Dy (9)] series 1, {[Ln3(TBrTA)6][Ln(H2O)8]•6H2O}n [Ln = Ho (10), Er (11), Tm (12), Yb (13), Lu (14)] series 2, respectively, were synthesized via slow evaporation with tetrabromoterep...

Four new [Pu(IV)(NO 3 )6-nCl n ] ²⁻ (n= 0, 2, 3) and [Pu(VI)O 2 (NO 3 )Cl 3 ] ²⁻ containing materials were crystallized from acidic, aqueous media and structurally characterized. The anions are assembled via hydrogen and halogen bonding motifs,...

Hybrid materials bearing elements from the 5f block display a rich diversity of coordination geometries, connectivities, and assembly motifs. In the Concept article by C. L. Cahill et al. on page 12747 ff., discuss examples of high anion media and coordination chemistry approaches to such materials, including delineation of assembly criteria, and t...

A series of nine new 4f-5f lanthanide-uranyl complexes, {[(UO2)2(O)(L1)(L2)2][UO2(L1)3][Ln(L1)3(L2)] • H2O}2, (where L1 and L2 are 2-thiophenecarboxylic acid (C5H3SO2) and 2,2’:6’2”-terpyridine (C15H11N3), respectively, and Ln = Pr3+ (1), Nd3+ (2), Sm3+ (3), Eu3+ (4), Gd3+ (5), Tb3+ (6), Dy3+ (7), Ho3+ (8), Er3+ (9)), and a uranyl only complex (10)...

The syntheses and crystal structures of four compounds containing the UO22+ cation and either benzoic acid (1), m-chlorobenzoic acid (2), m-bromobenzoic acid (3), or m-iodobenzoic acid (4) are described and the vibrational spectroscopic properties for compounds 3 and 4 are reported. Single crystal X-ray diffraction analysis of these materials shows...

An attractive method for valorization of glycerol is the catalytic transformation to lactic acid. By overcoming the solubility challenge associated with known homogeneous catalysts for this reaction, we show that thermally robust Ir(I), Ir(III), and Ru(II) N-heterocyclic carbene (NHC) complexes with sulfonate-functionalized wingtips are highly prol...

The synthesis and structural characterization of seven new [UO2(NCS)5]3-- and [UO2(NCS)4Cl]3--containing materials charge balanced by 4-phenylpyridinium or 4,4'-bipyridinium cations are reported. Assembly of these materials occurs via a diverse set of noncovalent interactions, with the most prevalent involving the terminal sulfur atoms, which can b...

The crystal structures of eight new binuclear peroxo-bridged uranyl (UO22+) complexes containing chelating N-donating ligands (2,2’-bipyridine [BPY] and 4,4’-dibromo-2,2’-bipyridine [BrBPY]) and various O-donating ligands (m-halobenzoic acid (where halo = fluoro, chloro, or iodo), p-toluic acid, 2-thiophenecarboxylic acid, acetate, benzoic acid, an...

A series of seven novel f-element bearing hybrid materials have been prepared from either methyl substituted 3,4 and 4,5-pyrazoledicarboxylic acids, or heterocyclic 1,3- diketonate ligands using hydrothermal conditions. Compounds 1, [UO2(C6H4N2O4)2(H2O)], and 3, [Th(C6H4N2O4)4(H2O)5]·H2O feature 1-Methyl-1H-pyrazole-3,4-dicarboxylate ligands (SVI-C...

Promotion of a synthon of choice for the non-covalent assembly of lanthanide tectons represents both a noteworthy challenge and opportunity within Ln(III) hybrid materials. We have developed a system wherein some control can be exercised over supramolecular assembly and, as part of continued efforts to improve this process we have generated a famil...

Crystals of a hydrated Pu(III) chloride, (C 5 H 5 NBr) 2 [PuCl 3 (H 2 O) 5 ] · 2Cl · 2H 2 O, were grown via slow evaporation from acidic aqueous, high chloride media. X-ray diffraction data reveals the neutral [PuCl 3 (H 2 O) 5 ] tecton...

The syntheses and crystal structures of six new complexes containing the UO22+ cation, m- or p-halobenzoic acid ligands (where halogens are Cl and I), and the chelating N-donors 1,10-phenanthroline (phen) (1, 3, 4, and 6) or 2,2':6',2"-terpyridine (terpy) (7 and 9) are described and compared to UO2-m-bromo- and p-bromobenzoic analogues (2, 5, and 8...

Six new heterometallic compounds containing the UO2²⁺ cation, o-, m-, and p-iodobenzoic acid ligands, and Tl⁺, Rb⁺, and Cs⁺ cations which adopt the role of both charge balancing cation and secondary metal center have been synthesized and their structural, supramolecular, and luminescent properties have been explored. Additionally, these compounds h...

Engaging the nominally terminal oxo atoms of the linear uranyl (UO22+) cation in non-covalent interactions represents both a significant challenge and opportunity within the field of actinide hybrid materials. We have developed an approach for promoting oxo atom participation in a range of non-covalent interactions through judicious choice of elect...

A family of twelve supramolecular [AnO2Cl4]²⁻ (An = U, Np, Pu) containing compounds assembled via hydrogen and halogen bonds donated by substituted 4-X-pyridinium cations, X = H, Cl, Br, I is reported. These materials were prepared from a robust room-temperature synthesis wherein crystallization of unhydrolyzed and valence pure [An(VI)O2Cl4]²⁻ (An...

The crystal structures of two new bimetallic uranyl–transition metal compounds with diglycolic acid [or 2-(carb­oxy­meth­oxy)acetic acid] have been hydro­thermally synthesized and structurally characterized via single-crystal X-ray diffraction. The compounds, namely catena-poly[[[tetra­aqua­manganese(II)]-μ-2,2′-oxydi­acetato-[dioxidouranium(VI)]-μ...

The enthalpies of formation from simpler components of four hybrid materials bearing the [UO2Cl4]²⁻ anion have been measured and compared to that of Cs2[(UO2)Cl4]. The hybrids contain protonated amines as charge balancing cations that form bifurcated H-bonding interactions with the chloro ligands of the anions. The structure of each material contai...

A one-dimensional La³⁺ coordination polymer, [La5(C15H11N3)(C7H4O2Br)15(H2O)]2 • H2O (compound 1), has been hydrothermally synthesized and characterized via single crystal and powder X-ray diffraction and crystallizes in the space group P . This compound has an asymmetric unit containing five lanthanum (La³⁺) metal centers and a repeating unit of t...

The synthesis and crystal structure of a new uranyl coordination polymer featuring 3-bromo-5-iodobenzoic acid is described and the luminescent and vibrational properties of the material have been explored. Compound (1), [UO2(C7H3BrIO2)2]n, features dimeric uranyl units chelated and then linked by 3-bromo-5-iodobenzoic acid ligands to form a one-dim...

Twenty-four new rare-earth p-bromobenzoic acid complexes, [RE(L¹)3(L²)(H2O)]2 (RE = La³⁺ (1), Ce³⁺ (2), Pr³⁺ (3), Nd³⁺ (4)), [RE(L¹)3(L²)(H2O)]2 (RE = La³⁺ (1′), Ce³⁺ (2′), Pr³⁺ (3′), Nd³⁺ (4′)), [RE(L¹)3(L²)]2·H2O (RE = Sm³⁺ (5), Eu³⁺ (6), Gd³⁺ (7), Tb³⁺ (8)), RE(L¹)3(L²)(H2O) (RE = Gd³⁺ (7′), Tb³⁺ (8′), Dy³⁺ (9), Ho³⁺ (10), Er³⁺ (11), Tm³⁺ (12),...

A series of twenty-one new rare-earth p-iodobenzoic acid complexes, [RE(L¹)3(L²)(H2O)]2 (RE = La³⁺ (1) Ce³⁺ (2)), [RE(L¹)3(L²)]2·H2O (RE = Ce³⁺ (2′), Pr³⁺ (3), Nd³⁺ (4), Sm³⁺ (5)), Eu³⁺ (6), Gd³⁺ (7), Tb³⁺ (8), Dy³⁺ (9), Ho³⁺ (10), Er³⁺ (11), Tm³⁺ (12), Yb³⁺ (13), Lu³⁺ (14), Y³⁺ (15)), [RE(L¹)3(L²)(H2O)]2 (RE = Yb³⁺ (13′), Lu³⁺ (14′), Y³⁺ (15′)), a...

The syntheses and crystal structures of 16 new rare-earth (RE = La(3+)-Y(3+))-3,5-dichlorobenzoic acid-terpyridine molecular materials characterized via single-crystal and powder X-ray diffraction are reported. These 16 complexes consist of four unique structure types ranging from molecular dimers (La(3+) and Ce(3+)) to tetramers (Pr(3+)-Y(3+)) as...

Orange crystals of K35 [(UO2)31Sm9(O2)51 (OH)22(H2O)6] (H2O)50—70 are prepared from aqueous solutions of UO2(NO3)2, Sm(NO3)3, KOH, and H2O2 (25 °C, 5 d).

A cage cluster consisting of 31 uranyl and 9 Sm(3+) polyhedra self-assembles in an alkaline aqueous peroxide solution and crystallizes (U31Sm9). Trimers of Sm(3+) polyhedra are templated by μ3-η(2):η(2):η(2)-peroxide groups and link to oxo atoms of uranyl ions. Three such trimers link into a ring through uranyl hexagonal bipyramids, and these are a...

Eight novel lanthanide metal organic frameworks (MOFs) and coordination polymers (CPs), La2(NTA)3(OH2)6 (1), [Nd(NTA)(HNTA)(OH2)2]·3H2O (2), [Nd2(NTA)3(OH2)2](H2O)3·2H2O (3), and [Ln2(NTA)3(OH2)2](H2O)2 (Ln = Sm (4), Eu (5), Gd (6), Tb (7), Er (8)), (H2NTA = 2-nitroterephthalic acid), have been synthesized under hydrothermal and slow evaporation co...

The syntheses and crystal structures of five new compounds containing the UO2²⁺ cation, 2,5-diiodobenzoic acid, and a chelating N-donor (2,2′-bipyridine (bipy) (1), 1,10-phenanthroline (phen) (2 and 3), 2,2′:6′,2′′-terpyridine (terpy) (4), or 4′-chloro-2,2′:6′,2′′-terpyridine (Cl-terpy) (5)) are described and the spectroscopic properties (both vibr...

Lanthanide-containing hybrid materials have garnered significant interest due to their rich structural diversity and have proven particularly attractive for a wide array of applications including gas storage, heterogeneous catalysis, magnetism, luminescence, and bioanalyses. Herein, we explore both polymeric and molecular lanthanide hybrid material...

The syntheses and crystal structures of six new compounds containing the UO22+ cation, 3,5-dichlorobenzoic acid, and a chelating N-donor [2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), 4,7-dimethyl-1,10-phenanthroline (dimethylphen), 2,2′:6′,2-terpyridine (terpy), 4′-chloro-2,2′:6′,2-terpyridine (Cl-terpy), or 2,4,6-tris(2-pyridyl)-s-triazine...

The structural chemistry of crystalline hybrid materials bearing the uranyl cation, [UO2]2 +, is reviewed. A theme of uranyl hydrolysis and complex aqueous speciation as drivers for structural diversity is developed for materials constructed from coordinate covalent bonding with various O- and N-donor ligands. We begin with results from a number of...

Four uranyl coordination polymers [UO2(C6H8O4)(H2O)2](C18H12N6)2 (1), [UO2(C8H4O4)(H2O)2](C18H12N6)2 (2), Na[(UO2)(C12H6O4)2](C18H13N6)·H2O (3), and Na[(UO2)(C16H8O4)(C6H3NO2)](C18H12N6)·H2O (4) containing aliphatic (adipic acid) or aromatic linkers (1,4-benzene dicarboxylic acid (BDC), 1,4-napthalene dicarboxylic acid (NDC), anthracene 9,10-dicarb...

Room temperature self-assembly of [UO2X4]2− (X=Cl, Br) with γ substituted pyridinium cations has resulted in the formation of twelve compounds that were studied via single crystal X-ray diffraction and fluorescence spectroscopy. Systematic variation of electron donating groups on the pyridinium species is shown to influence the presence and/or stre...

Eleven new lanthanide (Ln = Nd-Lu)-thiophene-2,5-dicarboxylic acid (25-TDC)-2,2':6',2''-terpyridine (terpy) coordination polymers () which employ a dual ligand strategy have been synthesized hydrothermally and structurally characterized by single crystal and powder X-ray diffraction. Two additional members of the series ( and ) were made with Ce(3+...

Seven uranyl coordination polymers [(UO2)(BrC8H3O4)(C15H11N3)] (1), [(UO2)(ClC8H3O4)(C15H11N3)] (2), [(UO2)(BrC8H3O4)(C18H12N6)] • H2O (3), [(UO2)(ClC8H3O4)(C18H12N6)] • 2H2O (4), [(UO2)(C8H3IO4)(C18H12N6)] • 2C3H7O (5), [(UO2)(C9H6O4)(C18H12N6)] • H2O (6), and [(UO2)(C6H2O4S)(C18H12N6)] • 2H2O (7) containing N-donor ligands 2,2’:6’,2”-terpyridine...

Thiophene 2,5-dicarboxylic acid (TDC) was reacted with uranyl acetate dihydrate and one (or none) of six N-donor chelating ligands (2,2’-bipyridine (BPY), 4,4’-dimethyl-2,2’-bipyridine (4-MeBPY), 5,5’-dimethyl-2,2’-bipyridine (5-MeBPY), 6,6’-dimethyl-2,2’-bipyridine (6-MeBPY), 4,4’,6,6’-tetramethyl-2,2’-bipyridine (4,6-MeBPY), and tetrakis(2-pyridy...

Three novel uranyl(VI) peroxide complexes, [(UO2)2(CH3COO)2(O2)(C10H8N2)] (1), [(UO2)2(CH3COO)2(O2)(C12H12N2)] (2), and [(UO2)3(CH3COO)4(O2)(C15H11N3)2] (3), have been synthesized and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, and luminescence spectroscopy. Each of these structures feature a [(UO2)2(O2)] dimer with...

The syntheses and crystal structures of twelve new compounds containing the UO22+ cation, a bromo-substituted benzoic acid linker (m-bromo-, p-bromo, or 3,5-dibromobenzoic acid) and a chelating N-donor (1,10-phenanthroline, 2,2′:6′,2′′-terpyridine, or 4′-chloro-2,2′:6′,2′′-terpyridine) are reported. Single crystal X-ray diffraction analyses of thes...

We report the first quantitative analysis of the structural evolution of a uranyl bearing coordination polymer in response to pressure. The material that is central to this study, (UO2)(O3PCH2CO2H) (1), is constructed from rigid 2D inorganic layers comprising edge sharing UO7 pentagonal bipyramids crosslinked by [PO3(COOH)](2-) anions. Strong hydro...

Eleven new rare earth (RE) p-chlorobenzoic acid-1,10-phenanthroline complexes have been hydrothermally synthesized and structurally characterized via single-crystal and powder X-ray diffraction. This series builds on four previous single complex studies to analyze the structural, supramolecular and luminescent properties of the set of binuclear mol...

Treatment of a molecular copper(II) 2,4-pyridinedicarboxylate metalloligand (CuL1) and a copper(11) 2,3-pyridinedicarboxylate coordination polymer (CuL2) with the uranyl cation (UO22+) under hydrothermal conditions has yielded three new coordination polymers: [(UO2)(H2O)(2)(C7H3NO4)(2)Cu] (1), [(UO2)(H2O)(2)(C7H3NO4)(2)Cu]center dot H2O (2), and [(...

Previous work from our group has focused on uranyl hybrid materials with para-substituted halogen benzoic acids.1 Applying a `cap and link' strategy we have successfully controlled the nuclearity of UO22+ in a series of coordination polymers and Ln3+ in a family of molecular materials.2,3 Here we have expanded on this strategy and produced a series...

Three dimensional lanthanide (Ln) framework compounds are renowned for their excellent photoluminescence properties, and there is growing interest in the development of this class of metal-organic framework (MOFs) materials for a diverse range of applications ranging from size-selective sensor technology to bio-imaging. Yet, although the physical a...

The development of a curriculum for nuclear materials courses targeting students pursuing Master of Arts degrees at The George Washington University is described. The courses include basic concepts such as radiation and radioactivity as well as more complex topics such the nuclear fuel cycle, nuclear weapons, radiation detection and technological a...

Four new UO22+ compounds were hydrothermally synthesized and incorporate 5-nitro-1,3-benzenedicarboxylic acid (n-bzdc): [(UO2)(C8N1O6H3)(H2O)]·H2O (1), [(UO2)2(C8N1O6H3)2H2O]·TEA (2); [(UO2)2(OH)(C8N1O6H3)2]·(TEAH)(H2O) (3); [(UO2)(C8N1O6H3)(C8N1O6H4)]·TMAH (4). Compound 1 consists of pentagonal bipyramidal uranyl monomers bridged via n-bzdc linker...

The synthesis and crystal structures of eight compounds containing the anionic uranyl isothiocyanate tecton [UO2(NCS)(4)(H2O)](2-), charge balanced by substituted pyridinium cations (4XpyH: X = Cl, Br, I, SCN, CH3, NH2, N(CH3)(2)) are reported. Hydrogen bonding interactions between coordinated water molecules and the non-coordinated sulfur atoms (O...

Uranyl-carboxyl­ate hybrid materials dominate the catalog of uranyl compounds owing in part to the affinity between COO⁻ functional groups and UO2²⁺. Polycarboxyl­ate organic ligands may present a degree of steric hindrance and could thus influence the resulting uranyl topology. Single crystals of the title compound, {(NH4)2[(UO2)2(C12O12)(H2O)2]}n...

Fifteen new lanthanide p-chlorobenzoic acid complexes, [PrL3(terpy)(H2O)]2 (1), [LnL3(terpy)(H2O)]2 (Ln = Nd (2), Sm (3), and Eu (4)), and [LnL3(terpy)(H2O)] (Ln = Sm (3′), Eu (4′), Gd (5), Tb (6), Dy (7), Ho (8), Er (9), Tm (10), Yb (11), Lu (12), and Y (13); HL: p-chlorobenzoic acid; terpy: 2,2′:6′,2′′-terpyridine), have been synthesized hydrothe...

Combination of CuI and tetrahydrothiophene (THT) in MeCN or neat THT produces various phases, depending upon experimental conditions. Green luminescent product (CuI)4(THT)2 (1) consists of Cu4I4 cubane units knit into a 3-D network by μ2-THT ligands. Dull yellow luminescent (CuI)10(THT)7(MeCN) (2)contains {[ Cu 4 I 4 (THT)]( μ 2 -THT) 2 (Cu 2 I 2 )...

Postsynthetic metalation of a uranyl isonicotinate starting material (UICP) with Ag(I) and Cu(II) under hydrothermal conditions has yielded two new coordination polymers: (UO2)(OH)(C6H4NO2)2Ag (1) and (UO2)2(O)(OH)(C6H4NO2)2Cu(OH2)Cl (2). The Ag(I) in 1 directly replaces a proton in UICP and thus generates a similar topology. Compound 2, however, i...

The reaction of two η5-cyclopentadienyliron(II)-functionalized terephthalate and phthalate metalloligands, namely [(η5-C5H5)FeII(η6-1,4-HO2CC6H4CO2H)][(η5-C5H5)FeII(η6-1,4-HO2CC6H4CO2)][PF6] and [(η5-C5H5)FeII(η6-1,2-HO2CC6H4CO2H)][(η5-C5H5)FeII(η6-1,2-HO2CC6H4CO2)][PF6]—hereafter [H2CpFeTP][HCpFeTP][PF6] and [H2CpFeP][HCpFeP][PF6], respectively—wi...

Aqueous reactions of copper(I) cyanide with 1-phenylpiperazine (PhPip) in the presence of KCN produce network compounds having CuCN:PhPip stoichiometries of 1:1, 3:2, and 4:1 depending on the mixing ratio used. In addition to these phases, hydrothermal synthesis yields a 5:3 network. Crystal structures of these four compounds are reported herein. T...

The synthesis, crystal structures, and Raman spectra of seven plutonium chloride compounds are presented. The materials are based upon Pu(VI)O2Cl4(2-) and Pu(IV)Cl6(2-) anions that are charge balanced by protonated pyridinium cations. The single crystal X-ray structures show a variety of donor-acceptor interactions between the plutonium perhalo ani...

Six homometallic and two heterometallic UO22+/M (M = Na+, Sm3+) hybrid materials were synthesized hydrothermally and incorporate either chelidamic acid (4-hydroxy-2,6-pyridinedicarboxylic acid) or its chlorine substituted derivative: 4-chloro-2,6-pyridinedicarboxylic acid (4-chloro-2,6-pydc): [UO2(C7H2NO5)·Et3NH] (1); [(UO2)2(C7H2NO5)2]·4H2O (2); [...

Three uranium(VI)-bearing materials were synthesized hydrothermally using the organic ligand 4,4'-biphenyldicarboxylic acid: (UO2)(C14O4H8) (1); [(UO2)2(C14O4H8)2(OH)]·(NH4)(H2O) (2); (UO2)2(C14O4H8)(OH)2 (3). Compound 1 was formed after 1 day at 180 °C in an acidic environment (pHi = 4.03), and compounds 2 and 3 coformed after 3 days under basic c...

The influence of pressure (over the 0–4.7 GPa range) on the photoluminescence emissions and crystal structure of the known 3D terbium-adipate metal-organic framework material Tb-GWMOF6 has been evaluated by high-pressure single-crystal X-ray diffraction and spectroscopic techniques. The results from this study show that this complex lanthanide fram...

A series of nonanuclear lanthanide(III) nanoclusters, (CH3)(3)NH[Ln(9)(L)(16)(mu(3)-OH)(8)(mu(5)-O)(2)](CH3OH) where Ln = Nd, Eu, Tb, Gd, Dy, Er, Yb and HL = (2-hydroxy-5-methylphenyl)propan-1-one, was successfully synthesized and characterized by photoluminescence, magnetic susceptibility and X-ray crystallography. (CH3)(3)NH[Gd-9(L)(16)(mu(3)-OH)...

The reaction of uranyl nitrate hexahydrate with 4-halopyridinium ions (X = Cl, Br, I) in high chloride media has resulted in three novel compounds, each of which is based around the [UO2Cl3(NO3)]2− tecton; (C5H5NCl)2[UO2Cl3(NO3)], (C5H5NBr)2[UO2Cl3(NO3)] and (C5H5NI)3[UO2Cl3(NO3)](NO3). In each material the halogen is involved in various forms of i...

Six novel uranyl terpyridine aromatic carboxylate coordination polymers, [UO(2)(C(6)H(2)O(4)S)(C(15)H(11)N(3))] (1), [UO(2)(C(6)H(2)O(4)S)(C(15)H(10)N(3)Cl)]·H(2)O (2), [UO(2)(C(8)H(4)O(4))(C(15)H(11)N(3))] (3), [UO(2)(C(8)H(4)O(4))(C(15)H(10)N(3)Cl)] (4), [UO(2)(C(12)H(6)O(4))(C(15)H(11)N(3))] (5), and [UO(2)(C(12)H(6)O(4))(C(15)H(10)N(3)Cl)] (6),...

Greenwoodie ideal formula Ba2-x(V3+OH)(x)V-9(Fe3+,Fe2+)(2)Si2O22, space group P (3) over bar m1, a 5.750(1) angstrom, c 14.459(1) angstrom, V 414.00(8) angstrom(3), Z = 1, is a new mineral from the Wigwam deposit of Southeastern British Columbia, Canada. It is a metamorphic mineral formed under greenschist-facies conditions as part of an assemblage...

Five isoreticular lanthanide (Ln) metal-organic frameworks (MOFs) – Er(bdc)(HCOO) (1a), Dy(bdc)(HCOO) (1b), Tb(bpdc)(HCOO) (2a), Gd(bpdc)(HCOO) (2b) and Tb(bpydc)(HCOO) (3) (bdc = 1,4-benzenedicarboxylate, bpdc = 4,4′-biphenyldicarboxylate and bpydc = 2,2′-bipyridine-5,5′-dicarboxylate) – were synthesized under solvothermal conditions. The complexe...

A study was conducted to demonstrate synthesis, speciation, and formation of solid-state structures of uranyl bearing hybrid materials. Investigations included uranyl hydrolysis, pH influence, building unit selectivity, and efforts to incorporate supramolecular tools to the formation of uranyl hybrids. A hybrid material was defined as a compound th...

Phase to phase: The in situ hydrolysis of 4-(bromomethyl)benzoic acid to 4-(hydroxymethyl)benzoic acid (HMBA) in the presence of the uranyl cation has resulted in the novel hybrid material (A)[UO(2) (HMBA)(3) ] (A=NH(4) (+) or H(3) O(+) ), which was characterized by X-ray diffraction. On exposure to ethanol the material undergoes a solid-state phas...