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Studies of the supramolecular chemistry of iso‐tellurazole N‐oxides have been confined to non‐polar media until now. To overcome that limitation, an iso‐tellurazole N‐oxide was derivatized with a primary alcohol group; the compound is soluble in polar solvents and stable in acidic to neutral aqueous media. Nickel (II) and iron (II) form macrocyclic complexes with six molecules of that iso‐tellurazole N‐oxide in a hitherto not‐observed macrocyclic arrangement defined by CTe⋅⋅⋅O chalcogen bonds and κ6‐O bound to the metal ion. This behaviour is in sharp contrast with the κn‐Te (n=1,2,4) complexes formed by soft metal ions. [ABSTRACT FROM AUTHOR]

A new synthesis that avoids the use of Me2PH is reported for (Me2PCH2BMe2)2, and this method was extended to the synthesis of (Ph2PCH2BMe2)2. The ligand precursor (Me2PCH2BMe2)2 did not react with [{M(μ-Cl)(cod)}2] (cod = 1,5-cyclooctadiene; M = Ir and Rh) or [PtCl2(cod)] at room temperature. However, after 12–48 hours at 65–70 °C, these reactions afforded (a) [Ir(cod)(μ-Cl)(Me2PCH2BMe2)] (1), (b) an equilibrium mixture of (Me2PCH2BMe2)2, [{Rh(μ-Cl)(cod)}2] and [Rh(cod)(μ-Cl)(Me2PCH2BMe2)] (2), and (c) cis-[Pt(μ-Cl)2(Me2PCH2BMe2)2] (3), respectively. By contrast, reactions between the phenyl-substituted analogue, (Ph2PCH2BMe2)2, and [{M(μ-Cl)(cod)}2] (cod = 1,5-cyclooctadiene; M = Ir and Rh) proceeded over the course of 1 hour at 20 °C to generate [M(cod)(μ-Cl)(Ph2PCH2BMe2)] (M = Ir (4) and Rh (5)), indicative of room temperature (Ph2PCH2BMe2)2 dissociation. Room temperature reactions of (Ph2PCH2BMe2)2 with [{Rh(μ-Cl)(coe)2}2] (coe = cyclooctene) using a 1 : 1 or 3 : 1 stoichiometry also afforded [{Rh(coe)(μ-Cl)(Ph2PCH2BMe2)}2] (6) or [RhCl(Ph2PCH2BMe2)3] (7), respectively, where the latter is a borane-appended analogue of Wilkinson's catalyst, and reactions of (Ph2PCH2BMe2)2 with [PtX2(cod)] (X = Cl or Me) yielded cis-[Pt(μ-Cl)2(Ph2PCH2BMe2)2] (8) and cis-[PtMe2(Ph2PCH2BMe2)2] (9). Compounds 1–9, (Me2PCH2BMe2)2 and (Ph2PCH2BMe2)2 were crystallographically characterized. In compounds 1–5 and 8, each chloride co-ligand is coordinated by the borane of an R2PCH2BMe2 ligand. Additionally, in the solid state structure of 6, each bridging chloride ligand interacts weakly with a pendent borane, and in 7, the chloride ligand is tightly coordinated to the borane of one Ph2PCH2BMe2 ligand and weakly coordinated to the borane of a second Ph2PCH2BMe2 ligand. By contrast, both boranes in 9 (and one of the three boranes in 7) are non-coordinated. [ABSTRACT FROM AUTHOR]

Reactions of the ethylene hydride complex trans-[(dmpe)2MnH(C2H4)] (1) with secondary hydrogermanes H2GeR2 at 55–60 °C afforded the base-free terminal germylene hydride complexes trans-[(dmpe)2MnH(＝GeR2)] (R = Ph; 2a, R = Et; 2b). Room temperature reactions of 2a or 2b with an excess of the primary hydrogermanes H3GeR′ (R′ = Ph or nBu) afforded trans-[(dmpe)2MnH(＝GeHR′)] (R′ = Ph; 3a, R′ = nBu; 3b) in rapid equilibrium with small amounts of 2a/b, as well as the digermyl hydride complex mer-[(dmpe)2MnH(GeH2R′)2] {R′ = Ph (4a) or nBu (4b)} and the trans-hydrogermane germyl complex trans-[(dmpe)2Mn(GeH2R′)(HGeH2R′)] {R′ = Ph (5a) or nBu (5b)}. Pure 3b was isolated from the reaction of 2b with H3GenBu, whereas 3a decomposed readily in solution in the absence of free H3GePh, and a pure bulk sample was not obtained. Reactions of 1 with H3GeR′ (R′ = Ph or nBu) also proceeded at 55–60 °C to afford mixtures of 3a/b, 4a/b and 5a/b, accompanied by remaining 1. However, upon continued heating to consume 1, various unidentified manganese-containing intermediates were formed, ultimately affording the germanide complex [{(dmpe)2MnH}2(μ-Ge)] (6) in 17–49% spectroscopic yield. Pure trans,trans-6 was isolated in 27% yield from the reaction of 1 with H3GenBu, and it is notable that this reaction involves stripping of all four substituents from the hydrogermane. Complexes 2a, 3a, and 6 were crystallographically characterized, and the nature of the Mn＝Ge bonding in these species (as well as in 2b and 3b) was probed computationally. [ABSTRACT FROM AUTHOR]

Iso-tellurazole N-oxides are promising supramolecular building blocks. While in neutral solutions, they form tetra-and hexameric macrocyclic aggregates linked by Te ... O secondary bonding (t hole interactions or chalcogen bonds), protonation of the oxygen atom in acidic media disrupts such supramolecular association. The process is reversible and, consequently, can be used to switch on and off the self-assembly process. Hammett acidity measurements gave p[K.sub.a] values of-3.2 for the protonated molecules. Adducts with HCl and HBr were isolated and structurally characterized. Protonation in solution led to the crystallization of a new polymorph of 3-methyl-5-phenyl-1,2- tellurazole N-oxide, which features a unique polymeric arrangement. Key words: sigma-hole interactions, secondary bonding, chalcogens, supramolecular chemistry, main-group chemistry. Les isotellurazoles N-oxydes sont des synthons supramoleculaires prometteurs. Bien qu'en solution neutre, ils forment des agregats macrocycliques tetrameriques et hexameriques retenus par des liaisons secondaires Te ... O (interactions de trous t ou liaisons chalcogene), en milieu acide, la protonation des atomes d'oxygene perturbe une association supramoleculaire de ce type. Ce processus d'association est reversible et peut donc etre utilise pour provoquer ou inhiber le processus d'autoassamblage. Nous avons calcule, pour les molecules protonees, une valeur de p[K.sub.a] de -3,2 derivee des mesures de l'acidite en utilisant l'equation de Hammett. En outre, nous avons isole des adduits de HCl et de HBr et en avons caracterise les structures. La protonation en solution a entraine la cristallisation d'un nouveau polymorphe du 3-methyl-5-phenyl-1,2-tellurazole Noxyde presentant une structure polymerique unique. [Traduit par la Redaction] Mots-cles : interactions de trous sigma, liaison secondaire, chalcogenes, chimie supramoleculaire, chimie du groupement principal., Introduction The remarkable success of halogen bonding (1-4) in areas as diverse as crystal engineering, (2,5-14) supramolecular catalysis, (15) anion recognition, (16) optical materials, (17) and biomimetic chemistry (18-20) has [...]

Reaction of 2 equivalents of (Me2PCH2AlMe2)2 with [{RhCl(cod)}2] (cod = 1,5-cyclooctadiene) afforded [{κ2P,P-(Me3Al)ClMeAl(CH2PMe2)2}Rh(cod)] (1), which features a κ2-coordinated bis(phosphino)aluminate anion. In compound 1, an Al–Cl substituent bridges to a molecule of AlMe3, which could be removed in vacuo to provide [{κ2P,P-ClMeAl(CH2PMe2)2}Rh(cod)] (2). By contrast, reaction of 1 equiv. of (Me2PCH2AlMe2)2 with [{RhCl(cod)}2] yielded [Rh(cod)(μ-Cl)(Me2PCH2AlMe2)] (3) as the major product, where the phosphine donor of an intact Me2PCH2AlMe2 ligand is coordinated to rhodium and a chloride ligand bridges between Rh and Al. [Rh(cod)(μ-Cl)(Me2PCH2AlClMe)] (3A) and 2 were also formed as minor products. The aforementioned reactions were carried out in benzene or toluene, whereas the 1 : 1 reaction of (Me2PCH2AlMe2)2 with [{RhCl(cod)}2] in THF afforded [{Rh(μ-CH2PMe2)(cod)}2] (4). Reactions of (Me2PCH2AlMe2)2 with iridium(I), gold(I) and platinum(II) precursors were also explored. A 1 : 1 reaction of (Me2PCH2AlMe2)2 with [{IrCl(cod)}2] afforded [{κ2P,P-Cl2Al(CH2PMe2)2}Ir(cod)] (5) as one of two major phosphine-containing products; unlike 3, this compound features two chlorine substituents on aluminium. For comparison, the rhodium analogue of 5, [{κ2P,P-Cl2Al(CH2PMe2)2}Rh(cod)] (6), was also synthesized via the 1 : 1 reaction of {ClAl(CH2PMe2)2}2 with [{RhCl(cod)}2]. Reactions of (Me2PCH2AlMe2)2 with [AuCl(CO)] or [PtCl2(cod)] also resulted in chloride–methyl group exchange between the transition metal and aluminium. However, these reactions generated free (Me2PCH2AlClMe)2 accompanied by gold and ethane, or [PtMe2(cod)], respectively. Reaction of 1.5 equivalents of (Me2PCH2AlMe2)2 with [PtMe2(cod)] at 75 °C afforded zwitterionic [(PtMe{μ-κ1P:κ2P,P-MeAl(CH2PMe2)3})2] (7) which features two tris(phosphino)aluminate anions bridging between PtMe units. Compounds 1–2, 3/3A, 4–7 and (Me2PCH2AlClMe)2 were crystallographically characterized. [ABSTRACT FROM AUTHOR]

The use of high-strength polymer in automotive structural components is limited by insufficient understanding of microscopic aspects of deformation for accurate numerical predictions of the mechanical behavior during forming processes. One approach to meeting these critical data needs is a careful examination of the structure property relationships that directly influence formability. Different hot forming processes (solid-state extrusion, axial feed hot oil tube forming, and biaxial ball stretching test) are utilized in this work for investigating the effect of process conditions on the molecular orientation of polypropylene (PP) tubes. White-Spruiell representation of orientation factors based on the results form X-ray diffraction (XRD) patterns is utilized to analyze the development of orientation under extrusion and various forming conditions. POLYM. ENG. SCI., 51:1446-1454, 2011. © 2011 Society of Plastics Engineers, INTRODUCTION One of the main goals of manufacturing of structural automotive parts is to create lighter, good quality parts at lower costs. High modulus structural thermoplastics appear to be promising [...]

Acetylferrocene readily forms an adduct with B[F.sub.3]. The product is a neutral model for protonated acetylferrocene, a species that is a crucial intermediate in the formation of 1,3,5-trisferrocenyl-benzene and other conjugated heterometallic derivatives by cyclocondensation. The title compound's structure was determined in the solid state by X-ray diffraction and its spectroscopic properties were examined in detail, particularly the electronic excitation spectrum, which confirms the previous identification of the in situ generated protonated ketone. Key words: organometallic ketones, B[F.sub.3] adducts, ferrocenyl cations, density functional theory (DFT) calculations. L'acetylferrocene forme facilement un adduit avec le B[F.sub.3]. Le produit est un modele neutre pour un acetylferrocene, une espece qui est un intermediaire crucial dans la formation du 1,3,5-trisferrocenyl-benzene et d'autres derives heterometalliques par cyclocondensation. La structure du compose mentionne dans le titre a ete determinee a l'etat solide par diffraction des rayons X et on a examine ses proprietes spectroscopiques en detail, en particulier son spectre d'excitation electronique qui confirme l'identification anterieure de la cetone protonee generee in situ. Mots-cles : cetones organometalliques, adduits avec le B[F.sub.3], cations ferrocenyles, calculs d'apres la theorie de la fonctionnelle de la densite (TFD). [Traduit par la Redaction], Introduction Aldehydes and ketones are weak bases, with the typical [pK.sub.a] values of their conjugated acids being below -6, e.g., -6.99 in the case of benzaldehyde and -6.04 for acetophenone. [...]

A general synthetic route is developed for the resonance-stabilized pyrazine-bridged bisdithiazolyl framework, involving the reductive deprotection of 2,6-diaminopyrazine-bisthiocyanate and cyclization with thionyl chloride. Variable-temperature single-crystal conductivity measurements have shown that the conductivity is activated at room temperature.

The long-range proton transport in cell membrane constituent phosphoric acid-doped poly(benzimidazole) is dependent on the phosphate anion dynamics. The solid state NMR data show that the phosphate anions have a faster tetrahedral reorientation and a four-site jump compared to a slower reorientation and a three site jump as observed of the methane phosphonate.

Hexaethylbenzene (HEB) and [(p-cymene)Ru[Cl.sub.2] react in the melt to yield [[(HEB)Ru[Cl.sub.2]].sub.2] (6), the NMR spectra of which reveal the presence of [[(HEB).sub.2][Ru.sub.2][(μ-Cl).sub.3]]Cl in solution. In [[(HEB).sub.2][Ru.sub.2][(μ-Cl).sub.3]][[C.sub.5][(C[O.sub.2]Me).sub.5]] (7), the cation has [D.sub.3h] symmetry with alternating proximal and distal ethyl groups. Bridge cleavage of 6 with trimethyl phosphite or with trimethylphosphine gives (HEB)Ru[Cl.sub.2] [P[(OMe).sub.3]] (9) or (HEB)Ru[Cl.sub.2](P[Me.sub.3]) (10), respectively. The latter reaction also yields Ru[Cl.sub.2][([Me.sub.3]P).sub.4] (11), whose structure represents a relatively rare example of a crystallographically characterized trans isomer of this type. In 9, five of the ethyl ligands are distal, whereas in 10 all six substituents are distal. Attempts to prepare the sandwich dication [[[(HEB).sub.2]Ru].sup.2+] gave instead [(HEB)Ru[([H.sub.2]O).sub.3]][(B[F.sub.4]).sub.2] (8), whose NMR and X-ray data reveal the 1,3,5-distal-2,4,6-proximal arrangement of ethyls both in the solid state and in solution. (HEB)Mn[(CO).sub.2]Br (13) likewise adopts the 1,3,5-distal-2,4,6-proximal structure in the solid state but, surprisingly, there is no evidence for slowed ethyl rotation in solution. Key words: hexaethylbenzene conformations, hindered rotations, crystallography, NMR, ruthenium, manganese. L'hexaethylbenzene (HEB) et le [[(p-cymene)Ru[Cl.sub.2]].sub.2] reagissent a l'etat fondu pour conduire a la formation de [[(HEB)Ru[Cl.sub.2]].sub.2] (6) dont le spectre RMN en solution revele la presence de [[(HEB).sub.2][Ru.sub.2] [(μ-Cl).sub.3]]Cl. Dans le [[(HEB).sub.2][Ru.sub.2][(μ-Cl).sub.3]][[C.sub.5] [(C[O.sub.2]Me).sub.5]] (7), le cation est de symetrie [D.sub.3h] avec, en alternance, des groupes ethyles de type distal et proximal. Le clivage du pont du compose 6 avec du phosphite de trimethyle ou avec de la trimethylphosphine conduit, selon le cas, au (HEB)Ru[Cl.sub.2] [P[(OMe).sub.3]] (9) ou au (HEB)Ru[Cl.sub.2](P[Me.sub.3]) (10). La derniere reaction fournit aussi du Ru[Cl.sub.2][([Me.sub.3]P).sub.4] (11) dont la structure correspond a un rare exemple d'un isomere trans de type a etre caracterise par cristallographie. Dans le compose 9, cinq sur six ligands sont de type distal alors que dans le compose 10 les six ligands sont tous de type distal. Des essais en vue de preparer le dication sandwich [[[(HEB).sub.2]Ru].sup.2+] on plutot conduit a la formation de [(HEB)Ru[([H.sub.2]O).sub.3]][(B[F.sub.4]).sub.2] (8) dans lequel, selon les donnees de la RMN et de la diffraction des rayons X, on observe un arrangement 1,3,5-distal-2,4,6-proximal des groupes ethyles tant 5 l'etat solide qu'en solution. La structure du (HEB)Mn(C[O.sub.2])Br (13) adopte aussi une structure 1,3,5-distal-2,4,6-proximal a l'etat solide, mais il est surprenant d'observer que, en solution, on n'observe aucune donnee laissant croire a un ralentissement de la rotation des groupes ethyles. Mots cles : conformation de l'hexaethylbenzene, rotations empechees, cristallographie, RMN, ruthenium, manganese. [Traduit par la Redaction], Introduction Hexaethylbenzene (HEB) is a conformationally versatile ligand! When bonded to organometallic fragments, such as Cr[(CO).sub.3] (1), [[Fe([C.sub.5][H.sub.5])].sup.+] (2), or [[Mo[(CO).sub.3]Cl].sup.+] (3), the ethyl groups can adopt a variety of [...]

New synthetic routes to 1,2,3-dithiazolo-1,2,3-dithiazolylium salts, based on double Herz condensations of N-alkylated 2,6-diaminopyridium salts with sulfur monochloride, are developed. The two prototypal 1,2,3-dithiazolo-1,2,3-dithiazolyl radicals HBPMe and HBPEt are prepared and characterized in solution by cyclic voltammetry and EPR spectroscopy.

3-Ferrocenyl-2,4,5-tri-([beta]-naphthyl)cyclopentadienone undergoes a Diels--Alder reaction with di-([beta]-naphthyl)acetylene to yield, after elimination of carbon monoxide, ferrocenyl-penta-([beta]-naphthyl)benzene (4). [sup.1]H and [sup.13]C variable-temperature NMR studies on 4 reveal the existence of multiple diastereoisomers at low temperature. These data are interpreted in terms of slowed rotation of the naphthyl groups, and are supported by the X-ray crystal structure of 4, which exhibits disorder at three of the naphthyl sites. Key words: sterically crowded molecules, hindered rotations, crystallography, NMR.

Research reveals that the dehydration of (1,12-dicarba-closo-dodecaboran-1-yl)formamide with the Burgess reagent leads to the formation of a methyl carbamate, whereas with triphosgene 2,3-bis(p-carboran-1-ylimino)azetidine is formed. Results indicate that these products are unusual.

Research has been conducted on the tamoxifen's analogue nido-carborane. The preparation of this carborane as an antiestrogen and a boron neutron capture therapy agent has been investigated and the details are presented.

Research has been conducted on the cyclohexanols. The treatment of these cyclohexanols with the alkynyl anions has been carried out and their structures have been compared with the dicobalt hexacarbonyl complex conformations characterized in a solid state by the X-ray crystallography.

Research has been conducted on the S-Se-N-based heterocycle benzo[2,1-c:3,4-c']bis(1,2,3-thiaselenazole). The preparation of this compound via the 1,4-diaminobenzene-2,3-dithiol with selenium tetrachloride has been carried out and the results indicate that the crystal of the compound are not isomorphous with the related benzo[2,1-c:3,4-c']bis(1,2,3-dithiazole).

Research into the phosphorus chemical shift and dipolar coupling tensors for tetramethyldiphosphine disulfide as characterized by 31P single-crystal NMR is presented. There was very good agreement between the calculated and experimental phosphorus chemical shift tensor orientations.

Chemical research using single-crystal phosphate-31 nuclear magnetic resonance and X-ray diffraction analysis shows that the molecular structure of the molybdenum phosphine complex (5-methyldibenzophosphole)pentacarbonylmolybdenum(0) is monoclinic and consists of unit cells which are between 7.7917(5) and 122.135 angstroms wide. Each crystal has a mirror plane which bisects the dibenophosphole framework.

X-ray cyrstallographic studies on chloro(triphenylmethyl)mono-, -di- and -trisulfanes reveal that the mono- and disulfanes have triclinic (P1) space groups which vary in their a,b,c, alpha, beta and gamma values. The trisulfane has an orthorhombic space group. The monosulfanes decompose to allotropic sulfur and phenylchloromethane at temperatures above their melting point. All three sulfanes undergo similar nucleophilic substitution reactions.

The complexes ((eta5-cppH)Mn(CO)3)PF6 (13) and (eta6-cppH)Cr(CO)3 (2) are obtained from the 4H-cyclopenta(def)phenanthrene (cppH) tetracyclic system. A terminal ring binds the metal in the above cases. Zwitterionic intermediates are not obtained during the deprotonation of (2) and (13), which yields (eta5-cpp)Mn(CO)3 (15) and ((eta5-cpp)Cr(CO)3)- (7). A 10 pi acharacter similar to naphthalene is retained when the polycyclic ligand undergoes eta3-binding by a migrating organometallic fragment.