The reaction of [UO2Cl4]2− with tBu-calix[6]arene (H6L) in the presence of lanthanum triflate in pyridine leads to the formation of [U{(H2L)LaCl2(NC5H5)4}2] (1); in the course of the reaction, the uranyl cations (UO22+) are transformed into U(+VI) alkoxides (1) and “UO6” oxides at the centre of the decametallic cluster [ULa9O8Cl15(O3SCF3)6(NC5H5)9]4− (2); complexes 1 and 2 are the first 4f–5f heterometallic complexes to be reported.

Reduction of the uranium(IV) thiolates Cp*2U(SR)2 (Cp* = η-C5Me5, R = Ph, Me, iPr or tBu) with sodium amalgam afforded the corresponding U(III) complexes Na[Cp*2U(SR)2] (R = Ph, 2a; Me, 2b; iPr, 2c) or the U(IV) sulfide Na[Cp*2U(StBu)(S)]. C−S bond cleavage of a thiolate ligand was also observed during the thermal decomposition of 2c into the sulfide Na[Cp*2U(SiPr)(S)], whereas 2b was transformed in refluxing THF into the thiametallacyclopropane complex Na[Cp*2U(SMe)(SCH2)], resulting from C−H bond activation of a SMe group. The X-ray crystal structures of [Na(18-crown-6)(THF)2][Cp*2U(SiPr)2], [Na(18-crown-6)][Cp*2U(StBu)(S)], and [Na(18-crown-6)(THF)2][Cp*2U(SMe)(SCH2)] have been determined.

The reactions of tBu-calix[6]arene (H6L) with Ln(O3SCF3)(3) (Ln = La, Sm, Yb) were used to isolate [{La(O3SCF3)(pyridine)(7)}(2)H2L] (1), [{SM(O3SCF3)(pyridine)(4)}(2)H2L] (2) and [{Yb(O3SCF3)(terpyridine)(pyridine)}(2)H2L] (3), three novel bimetallic calixarene complexes of the lanthanides. The solid state structures of 2 and 3 were determined by X-ray crystallography revealing compounds where the two metal cations are anchored on both sides of the macrocycle in the 1,2,3-alternate conformation. Compounds 1-3 are the first bis-alkoxy triflate species {M(OR)(2)(O3SCF3)} to be characterized in lanthanide coordination chemistry.

Octa(p-ydroxy)octakis(propyloxy)calix[8]arene.9(pyridine).2(H 2 O) crystallises in the triclinic space group P -1, a = 14.083(2), b = 14.478(2), c = 15.652(2) Å, α = 70.109(4), β = 74.146(3), γ = 75.572(4)°, V = 2843(1) Å 3 , Z = 1. Refinement led to a final R 1 value of 0.0757 for 4693 reflections. The calixarene sits around a crystallographic centre of inversion and is in the `chair-like' conformation. All p-hydroxyl groups form hydrogen bonds with either pyridine or water molecules leading the extended structure to be composed of infinite ribbons parallel to the [1,0,-1] direction.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The reactions of UCl4 with tBu-calix[4, 5, and 6]arenes (tBu-calix[n]arene = HnL[n]) were used to isolate [{UCl(L[4])}3O] (1), [{U(L[5])}2O]2− (2), and [U(H3L[6])2] (4). The dianionic species 2 could be oxidized to its UVI homologue [{U(L[5])}2O] (3). In contrast to 1−3 that are located around a μ-oxo bridge, 4 can be viewed as a homoleptic alkoxide. 1−4 are the first “non-uranyl” calixarene complexes of uranium to be reported.

Titration of the sulfonic protons of (p-sulfonato) calix [4] arene (H8L) with two equivalents of ethylenediamine affords [H3NCH2CH2NH3](2)[H4L(H2O)(3)].H2O, a molecular complex in which water is included inside the macrocycle. Deprotonation of one of the phenolic groups expels the water molecules from the aromatic cavity, leading to the formation of [H3NCH2CH2NH3](1.5)[(H3L) (H3NCH2CH2NH3)].(H2O)(5.5), which represents an unprecedented example of the inclusion of a dication in a calixarene. Further addition of ethylenediamine affords the mixed salt [H3NCH2CH2NH3](2)-[(H3L) (H3NCH2CH2NH2)].(H2O)(4.5) in which the monocation [H3NCH2CH2NH2](+) is preferentially bound to the cavity through a non-classical hydrogen bond involving an N-H...pi facial aromatic contact. Inclusion phenomena are indicated both by NMR and X-ray structure determinations. In the same way as their inorganic-organic counterparts, these clay-like materials are organised into parallel organic-organic layers.

C92H120O20. triclinic, P (1) over bar (No. 2), a=16.162(3)Angstrom, b = 16.234(3) Angstrom, c = 18.301(4) Angstrom, alpha = 75.82(3)degrees beta = 79.79(3)degrees, gamma = 71.16(3)degrees, V = 4380.6 Angstrom(3) Z= 2, R-gt(F)= 0.079, wR(ref)(F-2)= 0.229, T= 100 K.

tert-Butylcalix[12]arene (H12L) encompasses two uranyl bimetallic units inside its cavity to form [HNEt3](2)[{(UO2)(2)(NO3)(py)}(2)(H4L)] 1, the first metal complex of a large calixarene; the comparison of the crystal structures of 1 and H12L shows a relatively limited influence of metal coordination on the conformation of the macrocycle.

Gadolinium nitrate forms a complex with terpyridine at the interface between an aqueous solution of the metal cation and a chloroform solution of the organic ligand. The title complex, [Gd(terpy)(NO 3 ) 2 (H 2 O) 3 ]NO 3 (terpy = terpyridine, C 15 H 11 N 3 ), is ten-coordinate and its coordination polyhedron can be described as a distorted bicapped square antiprism. The coordinated nitrates are bidentate. The three water ligands form hydrogen bonds in the lattice.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The CS bond cleavage of a thiolate ligand of [U(Cp*)(2)(SBut)(2)] was induced by treatment with Na(Hg) and the title compound was isolated after addition of 18-crown-6; the crystal structure exhibited the unsupported U-S-Na linkage of the molecular complex, with a U-S bond distance of 2.462(2) Angstrom.

The reaction of [UO2Cl4]2– with tBu-calix[6]arene (H6L) is made possible by the presence of Cs+ leading to the formation of a trimetallic inclusion complex. An alkali metal can definitely influence the coordination chemistry of tBu-calix[6]arene.

Triscyclopentadienyl uranium (IV) thiolates were prepared by two principal methods namely (1) substitution of the chloride group of [U(cp)3(Cl)] (cp = η-C5H5) by Sr− and (2) oxidation of the trivalent precursors [U(cp)3(THF)] (THF = tetrahydrofuran), [U(C5H4SiMe3)3] and [U(C5H4tBu)3] with the disulfide RSSR (R = Me, Et, iPr, tBu or Ph).Similar treatment with MeSeSeMe afforded [U(cp)3(SeMe)] and [U(C5H4SiMe3)3(SeMe)]. The crystal structure of [U(cp)3(SMe)] was determined. Several reactions ofthese complexes are described, namely cleavage of the U-S bond by acidic substrates or iodine, insertion of Cs2 and CO2 into the U-S bond, and reduction into the corresponding U(III) anions. The synthesis, structure and reactivity of the thiolate compounds are compared with those of the alkoxide analogues.

Uranium(IV) tetrathiolate complexes were made by (a) reaction of U(NEt(2))(4) with RSH (R = Et, Pr-i, Bu(n) or Bu(t)), (b) treatment of U(BH4)(4) with RSH (R = Bu(n) or Ph) or of U(SBu(n))(4) with PhSH or (c) oxidation of uranium metal by RSSR (R = Et, Pr-i or Ph). Rearrangement of [U(SBu(t))(4)(py)(3)] (py = pyridine) in toluene gave the trinuclear cluster [U3S(SBu(t))10] with liberation of Bu(t)SH and Me(2)C=CH2. Reaction of U(SPri)(4) with [NEt(3)H][BPh(4)] in the presence of hexamethylphosphoric triamide (hmpa) afforded the cationic compound [U(SPri)(2)(hmpa)(4)][BPh(4)](2) which presents a trans-octahedral crystal structure. Iodinolysis of U(SPri)(4) in pyridine led to the formation of [U(SPri)(2)I-2(py)(3)] which adopts a pentagonal-bipyramidal configuration in its crystalline form. The trithiocarbonate ((PrS)-S-i)(2)C=S was obtained by reaction of U(SPri)(4) with CS2.

The absolute uraniumligand bond disruption enthalpies for the series of compounds U(Cp′)3SEt, U(Cp★)3SX (X  Et or tBu) and U(Ind★)3SEt [Cp′ C5H4tBu, Cp★  C5H4SiMe3 and Ind★  C9H6SiMe3] have been measured by an oxidative addition process involving batch-titration solution calorimetry in toluene. The derived values are as follows (kJ mol−1): 252 ± 8 (Cp′, Et); 266 ± 9 (Cp★, Et); 158 ± 8 (Cp★, tBu) and 158 ± 8 (Ind ★, Et).

The monocyclooctatetraene uranium bis(thiolate) complexes [U(cot)(SR)2] (cot = eta-C8H8, R = Bu(n) or Pr(i)) were prepared by treating [U(cot)(BH4)2] 1 with the corresponding thiol or NaSR reagent. The isopropane thiolate derivative is a dimer in the crystalline form, with four bridging SPr(i) ligands, and this structure is retained in solution. Reaction of 1 with NaSBu(t) afforded the anion [U(cot)(SBu(t))3]- which adopts a three-legged piano-stool configuration.