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A non-oxido V(v) complex with glutaroimide-dioxime (H3L), a ligand for recovering uranium from seawater, was synthesized from aqueous solution as Na[V(L)2]·2H2O, and the structure determined by X-ray diffraction., A non-oxido V(v) complex with glutaroimide-dioxime (H3L), a ligand for recovering uranium from seawater, was synthesized from aqueous solution as Na[V(L)2]·2H2O, and the structure determined by X-ray diffraction. It is the first non-oxido V(v) complex that has been directly synthesized in and crystallized from aqueous solution. The distorted octahedral structure contains two fully deprotonated ligands (L3–) coordinating to V5+, each in a tridentate mode via the imide N (R V–N = 1.96 Å) and oxime O atoms (R V–O = 1.87–1.90 Å). Using 17O-labelled vanadate as the starting material, concurrent 17O/51V/1H/13C NMR, in conjunction with ESI-MS, unprecedentedly demonstrated the stepwise displacement of the oxido V 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 O bonds by glutaroimide-dioxime and verified the existence of the “bare” V5+/glutaroimide-dioxime complex, [V(L)2]–, in aqueous solution. In addition, the crystal structure of an intermediate 1 : 1 V(v)/glutaroimide-dioxime complex, [VO2(HL)]–, in which the oxido bonds of vanadate are only partially displaced, corroborates the observations by NMR and ESI-MS. Results from this work provide important insights into the strong sorption of vanadium on poly(amidoxime) sorbents in the recovery of uranium from seawater. Also, because vanadium plays important roles in biological systems, the syntheses of the oxido and non-oxido V5+ complexes and the unprecedented demonstration of the displacement of the oxido VO bonds help with the on-going efforts to develop new vanadium compounds that could be of importance in biological applications.

New coordination assemblies furnish a rare crevice pyridine ligand or encapsulation of the closest not bonded CO3 2– species., The aerobic reaction of the multidentate ligand 2,6-bis-(3-oxo-3-(2-hydroxyphenyl)-propionyl)-pyridine, H4L, with Co(ii) salts in strong basic conditions produces the clusters [Co4(L)2(OH)(py)7]NO3 (1) and [Co8Na4(L)4(OH)2(CO3)2(py)10](BF4)2 (2). Analysis of their structure unveils unusual coordination features including a very rare bridging pyridine ligand or two trapped carbonate anions within one coordination cage, forced to stay at an extremely close distance (d O···O = 1.946 Å). This unprecedented non-bonding proximity represents a meeting point between long covalent interactions and “intermolecular” contacts. These original motifs have been analysed here through DFT calculations, which have yielded interaction energies and the reduced repulsion energy experimented by both CO3 2– anions when located in close proximity inside the coordination cage.

The initial use of 2-pyridyl-substituted oximes [(py)C(R)-NOH R = Me, Ph]/sulfate blend in nickel(II) chemistry has yielded a family of hexanuclear clusters. The syntheses, structures and magnetic properties are reported of [Ni6(SO4)4-(OH){(py)C(Me)NO} 3{(py)C(Me)NOH}3(MeOH)2(H2O)] (1), [Ni6(SO4)4(OH){(py)C(ph)NO}3{(py) C(ph)NOH}3(MeOH)3] (2) and [Ni6(SO 4)4(OH){(py)C(ph)NO}3{(py)C(ph)NOH} 3(H2O)3] (3), where (py)C(Me)NOH is methyl 2-pyridyl ketone oxime and (py)C(ph)NOH is phenyl 2-pyridyl ketone oxime. The hexanuclear molecules present in the three complexes have similar structures which contain the [Ni6(μ3-OH)(μ3-SO 4)3(μ3-ONR)3]2+ core. The core consists of six NiII ions arranged as two parallel equilateral triangular subunits, one small (Ni⋯Ni ca. 3.3 Å) and the other larger (Ni⋯Ni ca. 6.0 Å). Characteristic IR bands are discussed in terms of the known structures of 1-3. The magnetic properties of 1 and 2 have been studied by variable-temperature dc magnetic susceptibility techniques which indicate antiferromagnetic interactions. A simple 2-J model was found to be adequate to describe the similar thermal variation of the molar magnetic susceptibilities of 1 and 2. © Wiley-VCH Verlag GmbH & Co. KGaA, 2007. 18 2761 2774 Cited By :50

Metal-ion mediated reactions of 2-pyridinealdoxime and hexafluorophosphate lead to Zn II complexes containing picolinic acid, picolinamide and monofluorophosphate (-2) as ligands. © 2012 The Royal Society of Chemistry., S.P.P thanks the DFG-funded transregional collaborative research center SFB/TRR 88 “3MET” for support. C.D.P gratefully acknowledges University of Patras for an Erasmus Placement fellowship during her work in Karlsruhe and Alexander Onassis Public Benefit Foundation for a MSc fellowship (G ZG 034/ 2010-2011). E.M.-Z thanks the Research Committee of the University of Patras for financial support (C. Carathéodory Program, Grant 2008, C584). The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

International audience; The combined use of the anion of phenyl(2-pyridyl)ketone oxime (ppko(-)) and azides (N-3(-)) in nickel(II) carboxylate chemistry has afforded two new Ni-5(II) clusters, [Ni-5(O2CR')(2)(N-3)(4)(ppko)(4)(MeOH)(4)] [R' = H (1), Me (2)]. The structurally unprecedented {Ni-5(mu-N-3)(2)(mu(3)-N-3)(2)}(6+) cores of the two clusters are almost identical and contain the five Ni-II atoms in a bowtie topology. Two N-3(-) ions are end-on doubly bridging and the other two ions end-on triply bridging. The end-on mu(3)-N-3(-) groups link the central Ni-II atoms with the two peripheral metal ions on either side of the molecule, while the Ni center dot center dot center dot Ni bases of the triangles are each bridged by one end-on mu-N-3(-) group. Variable-temperature, solid-state direct(dc) and alternating-current (ac) magnetic susceptibility, and magnetization studies at 2.0 K were carried out on both complexes. The data indicate an overall ferromagnetic behavior and an S = 5 ground state for both compounds. The ac susceptibility studies on 1 reveal nonzero, frequency-dependent out-of-phase (chi(M)'') signals at temperatures below similar to 3:5 K; complex 2 reveals no chi(M)'' signals. However, single-crystal magnetization versus dc field scans at variable temperatures and variable sweep rates down to 0.04 K on 1 reveal no noticeable hysteresis loops, except very minor ones at 0.04 K assignable to weak intermolecular interactions propagated by nonclassical hydrogen bonds.

The employment of the anion of methyl 2-pyridyl ketone oxime (mpko(-)) as a tridentate chelating/bridging ligand in manganese chemistry is described. The inorganic anion (Br(-), ClO(4)(-)) used in the reaction affects the identity of the product. The reaction of MnBr(2) and one equivalent of mpkoH in the presence of a base affords [Mn(3)(OMe)(2)(mpko)(4)Br(2)] (3), which is mixed-valence (2Mn(II), Mn(IV)). The central Mn(IV) atom in each of the two, crystallographically independent, centrosymmetric molecules is coordinated by four oximate oxygen atoms belonging to the eta(1):eta(1):eta(1):mu mpko(-) ligands, and two eta(1):mu MeO(-) groups, while six coordination at each terminal Mn(II) atom is completed by four nitrogen atoms belonging to the 'chelating' part of two mpko(-) ligands, and one Br(-) ion. The Mn(II) atoms have trigonal prismatic coordination geometry. The reaction of Mn(ClO(4))(2).6H(2)O, mpkoH and OH(-) (1:2:1) in MeOH gives [Mn(8)O(4)(OMe)(mpko)(9)(mpkoH)](ClO(4))(4) (4), which is also mixed-valence (2Mn(II), 6Mn(III)) and possesses the novel [Mn(8)(mu(3)-O)(4)(mu-OMe)(mu-OR'')(2)](11+) core. The latter possesses a U-shaped sequence of four fused {Mn(II)Mn(III)(2)(mu(3)-O)}(6+) triangular units, with a Mn(III)-Mn(III) edge being shared between the central triangles. Variable-temperature, solid-state dc and ac magnetic susceptibility studies were carried out on complexes 3 and 4 . The dc susceptibility data for 3 in the 5.0-300 K range have been fit to a model with two J values, revealing weak ferromagnetic Mn(II)Mn(IV) (J = +3.4 cm(-1)) and Mn(II)Mn(II) (J' = +0.3 cm(-1)) exchange interactions. Fitting of the magnetization vs. H/T data by matrix diagonalization and including only axial anisotropy (ZFS, D) gave ground state spin (S) and D values of S = 13/2, D = +0.17 cm(-1) for and S = 3, D = -0.09 cm(-1) for 4 . The combined work demonstrates the usefulness of mpko(-) in the preparation of interesting Mn clusters, without requiring the co-presence of carboxylate ligands.

Ring a ring of roses: Spectacular nanoscale molecular assemblies have been created by design of individual polymetallic components that are then linked together through simple reactions. These include an assembly where six octametallic rings surround a dodecametallic central ring. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.