Evaluation of dispersion type metal···π arene interaction in arylbismuth compounds - an experimental and theoretical study.

The dispersion type Bi···π arene interaction is one of the important structural features in the assembly process of arylbismuth compounds. Several triarylbismuth compounds and polymorphs are discussed and compared based on the analysis of single crystal X-ray diffraction data and computational studies. First, the crystal structures of polymorphs of PhBi () are described emphasizing on the description of London dispersion type bismuth···π arene interactions and other van der Waals interactions in the solid state and the effect of it on polymorphism.

Syntheses of pentanuclear group 6 iridium clusters by core expansion of tetranuclear clusters with Ir(CO)2(η5-C5Me4R) (R = H, Me).

Metal cluster core expansion at tetrahedral group 6-group 9 mixed-metal clusters MIr3(μ-CO)3(CO)8(η(5)-L) (M = W, Mo, L = C5H5; M = Mo, L = C5Me5) with the iridium capping reagents Ir(CO)2(η(5)-L') (L' = C5Me5, C5Me4H) in refluxing toluene afforded the trigonal-bipyramidal clusters MIr4(μ-CO)3(CO)7(η(5)-C5H5)(η(5)-L') (M = Mo, L' = C5Me5, 1a; M = W, L' = C5Me5, 1b; M = Mo, L' = C5Me4H, 1c; M = W, L' = C5Me4H, 1d) and MoIr4(μ3-H)(μ-CO)2(μ-η(1):η(5)-CH2C5Me4)(CO)7(η(5)-C5Me5) (2). Related reactions with M2Ir2(μ-CO)3(CO)7(η(5)-L)2 (M = W, Mo, L = C5H5; M = Mo, L = C5Me5) afforded M2Ir3(μ-CO)3(CO)6(η(5)-C5H5)2(η(5)-L') (M = Mo, L' = C5Me5, 3a; M = W, L' = C5Me5, 3b; M = Mo, L' = C5Me4H, 3c; M = W, L' = C5Me4H, 3d), W2Ir3(μ-CO)4(CO)5(η(5)-C5H5)2(η(5)-C5Me4H) (4), and Mo2Ir3(μ-CO)3(CO)6(η(5)-C5Me5)3 (5). Single-crystal X-ray diffraction studies of 1a-1d, 2, 3a-3d, and 4 confirmed their molecular structures, including the μ-η(1):η(5)-CH2C5Me4 ligand at hydrido cluster 2, derived from a C-H bond activation of one of the methyl groups.

Remarkable in vitro bactericidal activity of bismuth(III) sulfonates against Helicobacter pylori.

Four new tris-substituted bismuth(III) sulfonates of general formula [Bi(O(3)SR)(3)] (R = phenyl 1, p-tolyl 2, 2,4,6-mesityl 3 and S-(+)-10-camphoryl 4) have been synthesised and characterised. Their synthesis by solvent-free (SF) and solvent-mediated (SM) methods has been explored and their activity against Helicobacter pylori has been investigated. The compounds 1-4 display a remarkable in vitro activity against three laboratory strains of H.

Caging peroxide: anion-templated synthesis and characterization of a rare-earth cluster.

Sequestration of peroxide derived from molecular oxygen has resulted in the templated synthesis of a terbium picolinate cluster, isolated as a 2D sodiated network in the solid state. This first example of an air-stable rare-earth peroxide cluster represents key evidence for a peroxide-containing intermediate in rare-earth-cluster-catalyzed oxidation reactions. Luminescent and magnetic properties have also been investigated.

Systematic study of the formation of the lanthanoid cubane cluster motif mediated by steric modification of diketonate ligands.

The treatment of ortho ring-functionalised 1-phenylbutane-1,3-dione ligands bearing nitro (Hnpd, Hnmc), methoxy (Hmmc) or fluoro (Hfpp) groups with hydrated lanthanoid salts has provided [Er(4)(μ(3)-OH)(4)(H(2)O)(2)(npd)(8)] (3), [Ln(4)(μ(3)-OH)(4)(nmc)(8)] (Ln = Gd (4), Tb (5), Dy (6) and Er (7)), [Er(4)(μ(3)-OH)(4)(mmc)(8)] (8) and [Er(4)(μ(3)-OH)(4)(H(2)O)(2)(fpp)(8)] (9), respectively. The products were all obtained as cubane clusters in the solid state, as distinct from previous diketonato clusters, with control over motif formation attributed to the steric influence of the ortho-positioned functional groups at the cluster periphery. This work highlights a means of targeting a specific lanthanoid cluster motif by the rational modification of ligands at key locations.

Synthesis, structural, and photophysical investigation of diimine triscarbonyl Re(I) tetrazolato complexes.

The synthesis, structural, and photophysical properties of a novel family of neutral fac-[Re(N(∧)N)(CO)(3)(L)] complexes, where N(∧)N is either 2,2'-bipyridine or 1,10-phenanthroline and L is a para functionalized 5-aryltetrazolate [namely, 5-phenyltetrazolate (Tph(-)), 4-(tetrazolate-5-yl)benzaldehyde (Tbdz(-)), 5-(4-acetylphenyl)tetrazolate (Tacy(-)), and methyl 4-(tetrazolate-5-yl)benzoate (Tmeb(-))] are reported. The complexes were prepared by direct addition of the corresponding tetrazolate anion to the acetonitrile solvated fac-[Re(N(∧)N)(CO)(3)](+) precursor. NMR data demonstrate that the coordination of the metal fragment is regiospecific at the N2 atom of the tetrazolate ring.

Anti-Leishmanial activity of homo- and heteroleptic bismuth(III) carboxylates.

Bismuth(III) complexes of NSAIDs (Non-Steroidal Anti Inflammatory Drugs) and substituted benzoic acids (o-methoxybenzoic acid, m-methoxybenzoic acid, o-nitrobenzoic acid, 3,5-diacetamidobenzoic acid, and 5-[(R/S)-2,3-dihydroxypropyl carbamoyl]-2-pyridine carboxylic acid) have been synthesised and fully characterised. Two new bis-carboxylato bismuth complexes have been characterised by single crystal X-ray diffraction, namely [PhBi(o-MeOC(6)H(4)CO(2))(2)(bipy)]·0.5EtOH (bipy=2,2'-bipyridine) and [PhBi(C(9)H(11)N(2)O(3)CO(2))(2)(H(2)O)]·6H(2)O.

Structural and solution studies of phenylbismuth(III) sulfonate complexes and their activity against Helicobacter pylori.

Three bis-phenylbismuth sulfonates [Ph(2)Bi(O(3)SR)](∞) (R = p-tolyl 1, mesityl 2 or S-(+)-10-camphoryl 3) have been synthesised and characterised. Their tendency for ligand redistribution in solution, and activity against the bacterium Helicobacter pylori have been investigated. The structures of 2 and 3 have been authenticated by X-ray diffraction crystallography.

Monitoring the stepwise assembly of a 3-D framework from a supramolecular lanthanoid synthon by in situ infrared spectroscopy.

Construction of a 3-D supramolecular network from [Ln(cpb)(3)(H(2)O)(2)] (Ln = Nd, Tb; Hcpb = 1-(4-cyanophenyl)-1,3-butanedione) by sequential displacement of a coordinated water by DMF, dimerisation by reciprocal hydrogen bonding in solution and pi-pi stacking and interdigitation of nitriles has been monitored by in situ fourier transform infrared spectroscopy.

Synthesis and structural characterization of cationic 5-hydroxy-1,3-diketonate stabilized dinuclear complexes and tetranuclear lanthanoid clusters.

5-Hydroxy-1,3-diketonate ligands have been found to stabilize dimeric complexes and tetrameric lanthanoid clusters dependent on the degree of steric bulk provided by the presence or absence of a methoxy group. Treatment of (R/S,Z)-1'-hydroxy-3-(hydroxy(phenyl)methylene)bi(cyclopentan)-2-one (Hhpb) and the p-methoxyphenyl derivative (Hhmb) with [LnCl(2)(H(2)O)(6)]Cl yields clusters of composition [Ln(4)(Cl)(2)(O)(hpb)(6)]Cl(2) (Ln = Nd (1), Ho (2), Tb (3), and Er (4)) and [Ln(2)(hmb)(5)]Cl (Ln = La (5), Nd (6), Tb (7), Dy (8), and Er (9)). Single crystal X-ray analysis of the tetranuclear cluster has revealed the lanthanoid core to be in a tetrahedral arrangement around a central mu(4)-oxygen, bridged by symmetrical chlorides and shrouded in six bridging hpb ligands.

Bismuth(III) 5-sulfosalicylate complexes: structure, solubility and activity against Helicobacter pylori.

Treatment of 5-sulfosalicylic acid (H(3)Ssal) with BiPh(3) results in the formation of the first dianionic carboxylate-sulfonate bismuth complex, [PhBi(HSsal)H(2)O](infinity) 1a, and its ethanol analogue [PhBi(HSsal)EtOH](infinity) 1b (space group P2(1)/c), while Bi(OAc)(3) gives the mixed monoanionic and dianionic complex, {[Bi(HSsal)(H(2)Ssal)(H(2)O)(3)](2) x 2 H(2)O}(infinity) 2 (space group P1). The three complexes are all polymeric in the solid state as determined by single crystal X-ray diffraction, with extended frameworks constructed from dimeric [Bi(HSsal)](2), 1a and 1b, or from [Bi(HSsal)(H(2)Ssal)](2) units, 2. The heteroleptic bismuth complexes 1a and 2 display remarkable aqueous solubility, 10 and 2.

A spectroscopic study of nicotine analogue 2-phenylpyrrolidine (PPD) using resonant two-photon ionization (R2PI), microwave, and 2D NMR techniques.

Conformational preferences of the nicotine analogue 2-phenylpyrrolidine (PPD) have been studied in both gaseous and solution phases. Theoretical calculations at the MP2 and B3LYP levels point to 5-6 stable conformers which differ in three degrees of conformational freedom; torsion between the two rings, inversion at the pyrrolidine (PY) amine, and PY ring puckering, characterized using the Cremer-Pople definition for pseudorotation. Only one conformer has a trans arrangement between the amino hydrogen and the phenyl substituent.

BiPh3--a convenient synthon for heavy alkaline-earth metal amides.

Environmentally friendly, commercially available BiPh3 reacts with heavy alkaline-earth metals (Ae) and bulky trimethylsilylamines to give the corresponding amides [Ae{N(SiMe3)(R)}2(thf)n] (R=SiMe3, 2,4,6-Me3C6H2, 2,6-iPr2C6H3) in good yields, providing proof of concept for a general synthetic method.

A new Na/Mg inverse crown ether.

A 'missing' member of the inverse crown ether family, namely mu(4)-oxo-tetrakis(mu-2,2,6,6-tetramethylpiperidinido)dimagnesium(II)disodium(I), [Na(2)Mg(2)O(C(9)H(18)N)(4)], has been synthesized by blocking the alternative aromatic metallation route via the use of sterically hindered 1,3,5-mesitylene as a solvent. [Na(2)Mg(2)O(NR(2))(4)] (NR(2) is 2,2,6,6-tetramethylpiperidinide) is shown to form a cationic planar eight-membered ring with alternating metal and N atoms, which captures at its core an oxide guest that lies on an inversion centre [principal dimensions: Na-O = 2.2405 (11) A, Na-N = 2.

Landmark Crystal Structure of an Experimentally Utilized Tetralithium-Tetrapotassium Amide-Alkoxide Superbase.

At long last an experimentally utilized superbase has been crystallographically characterized. Isolated from a lithium amide-potassium alkoxide-arene mixture, this landmark compound adopts a novel sixteen-vertex "carousel" arrangement stabilized by two distinct types of benzene ligation.