The influence of cage size on the reactivity of trimetallic nitride metallofullerenes: a mono- and bis-methanoadduct of Gd3N@C80 and a monoadduct of Gd3N@C84

A reactivity study of the higher TNT EMFs of gadolinium is reported here showing that the reactivity substantially decreases when the fullerene cage gets larger.     

Solvation effects with a photoresponsive two-component 12-hydroxystearic acid-azobenzene additive organogel

A "light-triggerable" azobenzene amine derivative (additive 1) was synthesized and then introduced into organogels of 12-hydroxystearic acid (HSA) in the molar ratio of 1:3. The organogels (HSA/1) consisting of additive 1 and HSA were analyzed by (1)H nuclear magnetic resonance (NMR), Fourier transform-infrared (FT-IR), and X-ray diffraction (XRD). The homogeneity of the gel networks was observed using field emission scanning electron microscopy (FE-SEM). Additive 1 formed a complex with HSA in HSA organogels due to salification between the terminal amine group of additive 1 and the carboxylic acid group of HSA. Additive 1 in the gels of HSA/1 showed the potential for photo-isomerization, and we achieved a reversible control of HSA/1 sol-gel transition in toluene by the alternating irradiation with UV and visible light. Interestingly, the opposite phenomenon was observed in CHCl(3) system, namely, the orange solution of HSA/1 in CHCl(3) was turned to a red-transparent gel by exposure to UV light.     

Atom tunneling in organic transformations

There and gone: atoms, such as hydrogen or deuterium, commonly disappear and reappear at different locations in molecular structures. For example, carboxylic acids and hydroxycarbenes isomerize through atom tunneling events. It could happen in your reaction!     

Multi-configurational quantum chemical studies of the Tc2X8(n-) (X = Cl, Br; n = 2, 3) anions. Crystallographic structure of octabromoditechnetate(3-)

The [Cs((2 + x))][H(3)O((1 - x))]Tc(2)Br(8)·4.6H(2)O (x = 0.221) salt has been synthesized and characterized by single crystal XRD. Multi-configurational quantum chemical calculations on Tc(2)X(8)(n-) (X = Cl, Br; n = 2, 3) have been performed and indicate the π component in the Tc-Tc bond to be stronger for n = 3.     

A new fatty aldol ester from the aerial part of Mimosa invisa (Mimosaceae)

A new aldol ester named 17-O-triacontanoylheptadecanal (1) was isolated from the aerial part of Mimosa invisa (Mimosaceae) together with eight known compounds identified as β-sitosterol (2), α-amyrine (3), lupeol (4), 4'-O-methylepinumisoflavone (5), alpinumisoflavone (6), betulinic acid (7), 3-O-β-D-glucopyranoside of sitosterol (8) and epirobinetinidol (9). The structures of compounds were determined on the basis of NMR and mass spectrometry data as well as by comparing the data reported in the literatures. The antimicrobial activities of the crude extract and compounds 1 and 9 were investigated against seven microbial species. The natural products showed moderate activities compared to that of the crude extract.     

Simultaneous analysis of plasma and CSF by NMR and hierarchical models fusion

Because cerebrospinal fluid (CSF) is the biofluid which interacts most closely with the central nervous system, it holds promise as a reporter of neurological disease, for example multiple sclerosis (MScl). To characterize the metabolomics profile of neuroinflammatory aspects of this disease we studied an animal model of MScl-experimental autoimmune/allergic encephalomyelitis (EAE). Because CSF also exchanges metabolites with blood via the blood-brain barrier, malfunctions occurring in the CNS may be reflected in the biochemical composition of blood plasma. The combination of blood plasma and CSF provides more complete information about the disease. Both biofluids can be studied by use of NMR spectroscopy. It is then necessary to perform combined analysis of the two different datasets. Mid-level data fusion was therefore applied to blood plasma and CSF datasets. First, relevant information was extracted from each biofluid dataset by use of linear support vector machine recursive feature elimination. The selected variables from each dataset were concatenated for joint analysis by partial least squares discriminant analysis (PLS-DA). The combined metabolomics information from plasma and CSF enables more efficient and reliable discrimination of the onset of EAE. Second, we introduced hierarchical models fusion, in which previously developed PLS-DA models are hierarchically combined. We show that this approach enables neuroinflamed rats (even on the day of onset) to be distinguished from either healthy or peripherally inflamed rats. Moreover, progression of EAE can be investigated because the model separates the onset and peak of the disease.     

Anthracene-tethered ruthenium(II) arene complexes as tools to visualize the cellular localization of putative organometallic anticancer compounds

Anthracene derivatives of ruthenium(II) arene compounds with 1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane (pta) or a sugar phosphite ligand, viz., 3,5,6-bicyclophosphite-1,2-O-isopropylidene-α-d-glucofuranoside, were prepared in order to evaluate their anticancer properties compared to the parent compounds and to use them as models for intracellular visualization by fluorescence microscopy. Similar IC(50) values were obtained in cell proliferation assays, and similar levels of uptake and accumulation were also established. The X-ray structure of [{Ru(η(6)-C(6)H(5)CH(2)NHCO-anthracene)Cl(2)(pta)] is also reported.     

Probing the Presence of Multiple Metal-Metal Bonds in Technetium Chlorides by X-ray Absorption Spectroscopy: Implications for Synthetic Chemistry

The cesium salts of [Tc(2)X(8)](3-) (X = Cl, Br), the reduction product of (n-Bu(4)N)[TcOCl(4)] with (n-Bu(4)N)BH(4) in THF, and the product obtained from reaction of Tc(2)(O(2)CCH(3))(4)Cl(2) with HCl(g) at 300 °C have been characterized by extended X-ray absorption fine structure (EXAFS) spectroscopy. For the [Tc(2)X(8)](3-) anions, the Tc-Tc separations found by EXAFS spectroscopy (2.12(2) ? for both X = Cl and Br) are in excellent agreement with those found by single-crystal X-ray diffraction (SCXRD) measurements (2.117[4] ? for X = Cl and 2.1265(1) ? for X = Br). The Tc-Tc separation found by EXAFS in these anions is slightly shorter than those found in the [Tc(2)X(8)](2-) anions (2.16(2) ? for X = Cl and Br). Spectroscopic and SCXRD characterization of the reduction product of (n-Bu(4)N)[TcOCl(4)] with (n-Bu(4)N)BH(4) are consistent with the presence of dinuclear species that are related to the [Tc(2)Cl(8)](n-) (n = 2, 3) anions. From these results, a new preparation of (n-Bu(4)N)(2)[Tc(2)Cl(8)] was developed. Finally, EXAFS characterization of the product obtained from reaction of Tc(2)(O(2)CCH(3))(4)Cl(2) with HCl(g) at 300 °C indicates the presence of amorphous α-TcCl(3). The Tc-Tc separation (i.e., 2.46(2) ?) measured in this compound is consistent with the presence of Tc═Tc double bonds in the [Tc(3)](9+) core.     

On the structure of β-molybdenum dichloride

The structure of β-molybdenum dichloride is compared with that of TcCl(2) using EXAFS spectroscopy. For TcCl(2), the Tc atom is surrounded by Tc atoms at 2.13(2), 3.45(3), 3.79(4), and 4.02(4) ?. For β-MoCl(2), the Mo is surrounded by Mo atoms at 2.21(2), 2.91(3), and 3.83(4) ?. The latter distances are consistent with the presence of an [Mo(4)Cl(12)] unit in the solid state, one constituted by two triply Mo-Mo-bonded [Mo(2)Cl(8)] units. First-principles calculations show that β-MoCl(2) with the TcCl(2) "structure type" is less stable than α-MoCl(2) (Mo(6)Cl(12)) or [Mo(4)Cl(12)] edge-sharing clusters.     

First and Second Order Necessary Conditions for Stochastic Optimal Control Problems

In this work we consider a stochastic optimal control problem with either convex control constraints or finitely many equality and inequality constraints over the final state. Using the variational approach, we are able to obtain first and second order expansions for the state and cost function, around a local minimum. This fact allows us to prove general first order necessary condition and, under a geometrical assumption over the constraint set, second order necessary conditions are also established. We end by giving second order optimality conditions for problems with constraints on expectations of the final state.