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Oncostatin M (OSM) and leukemia inhibitory factor (LIF) signaling protects the heart after myocardial infarction (MI). In mice, oncostatin M receptor (OSMR) and leukemia inhibitory factor receptor (LIFR) are selectively activated by the respective cognate ligands while OSM activates both the OSMR and LIFR in humans, which prevents efficient translation of mouse data into potential clinical applications. We used an engineered human-like OSM (hlOSM) protein, capable to signal via both OSMR and LIFR, to evaluate beneficial effects on cardiomyocytes and hearts after MI in comparison to selective stimulation of either LIFR or OSMR. Cell viability assays, transcriptome and immunoblot analysis revealed increased survival of hypoxic cardiomyocytes by mLIF, mOSM and hlOSM stimulation, associated with increased activation of STAT3. Kinetic expression profiling of infarcted hearts further specified a transient increase of OSM and LIF during the early inflammatory phase of cardiac remodeling. A post-infarction delivery of hlOSM but not mOSM or mLIF within this time period combined with cardiac magnetic resonance imaging-based strain analysis uncovered a global cardioprotective effect on infarcted hearts. Our data conclusively suggest that a simultaneous and rapid activation of OSMR and LIFR after MI offers a therapeutic opportunity to preserve functional and structural integrity of the infarcted heart.

Hypoxia signaling plays a major role in non-malignant and malignant hyperproliferative diseases. Pulmonary hypertension (PH), a hypoxia-driven vascular disease, is characterized by a glycolytic switch similar to the Warburg effect in cancer. Ras association domain family 1A (RASSF1A) is a scaffold protein that acts as a tumour suppressor. Here we show that hypoxia promotes stabilization of RASSF1A through NOX-1- and protein kinase C- dependent phosphorylation. In parallel, hypoxia inducible factor-1 α (HIF-1α) activates RASSF1A transcription via HIF-binding sites in the RASSF1A promoter region. Vice versa, RASSF1A binds to HIF-1α, blocks its prolyl-hydroxylation and proteasomal degradation, and thus enhances the activation of the glycolytic switch. We find that this mechanism operates in experimental hypoxia-induced PH, which is blocked in RASSF1A knockout mice, in human primary PH vascular cells, and in a subset of human lung cancer cells. We conclude that RASSF1A-HIF-1α forms a feedforward loop driving hypoxia signaling in PH and cancer., Pulmonary hypertension is characterized by a metabolic switch similar to the Warburg effect in cancer. Here Dabral et al. describe a RASSF1a-HIF-1α feedforward loop driving the Warburg effect both in a mouse model of hypoxia-induced pulmonary hypertension and a subset of human cancer cells.

The element lithium has been discovered 200 years ago. Due to its unique properties it has emerged to play a vital role in industry, esp. for energy storage, and lithium-based products and processes support sustainable technological developments. In addition to the many uses of lithium in its inorganic forms, lithium has a rich organometallic chemistry. The development of organometallic chemistry has been hindered by synthetic problems from the start. When Wilhelm Schlenk developed the basic principles to handle and synthesize air- and moisture-sensitive compounds, the road was open to further developments. After more information was available about the stability and solubility of such compounds, they started to play an essential role in other fields of chemistry as alkyl or aryl transfer reagents.

Cardiac healing after myocardial ischemia depends on the recruitment and local expansion of myeloid cells, particularly macrophages. Here we identify Reg3β as an essential regulator of macrophage trafficking to the damaged heart. Using mass spectrometry-based secretome analysis, we found that dedifferentiating cardiomyocytes release Reg3β in response to the cytokine OSM, which signals through Jak1 and Stat3. Loss of Reg3β led to a large decrease in the number of macrophages in the ischemic heart, accompanied by increased ventricular dilatation and insufficient removal of neutrophils. This defect in neutrophil removal in turn caused enhanced matrix degradation, delayed collagen deposition and increased susceptibility to cardiac rupture. Our data indicate that OSM, acting through distinct intracellular pathways, regulates both cardiomyocyte dedifferentiation and cardiomyocyte-dependent regulation of macrophage trafficking. Release of OSM from infiltrating neutrophils and macrophages initiates a positive feedback loop in which OSM-induced production of Reg3β in cardiomyocytes attracts additional OSM-secreting macrophages. The activity of the feedback loop controls the degree of macrophage accumulation in the heart, which is instrumental in myocardial healing.

Sirtuins (Sirt1-Sirt7) are NAD+-dependent protein deacetylases/ADP ribosyltransferases, which play decisive roles in chromatin silencing, cell cycle regulation, cellular differentiation, and metabolism. Different sirtuins control similar cellular processes, suggesting a coordinated mode of action but information about potential cross-regulatory interactions within the sirtuin family is still limited. Here, we demonstrate that Sirt1 requires autodeacetylation to efficiently deacetylate targets such as p53, H3K9, and H4K16. Sirt7 restricts Sirt1 activity by preventing Sirt1 autodeacetylation causing enhanced Sirt1 activity in Sirt7-/- mice. Increased Sirt1 activity in Sirt7-/- mice blocks PPARγ and adipocyte differentiation, thereby diminishing accumulation of white fat. Thus, reduction of Sirt1 activity restores adipogenesis in Sirt7-/- adipocytes in vitro and in vivo. We disclosed a principle controlling Sirt1 activity and uncovered an unexpected complexity in the crosstalk between two different sirtuins. We propose that antagonistic interactions between Sirt1 and Sirt7 are pivotal in controlling the signaling network required for maintenance of adipose tissue.

Lithium-containing hydrides and some derivatives are mainly used in synthetic chemistry for the selective reduction of functional groups. Hydrogen storage applications of complex Li hydrides and reactive mixtures with other metal hydrides or amides have been investigated thoroughly, but practical applications are hampered due to limited reversibility and unfavorable conditions for the sorption and desorption of hydrogen. In the field of electrochemical energy storage, complex Li-containing hydrides are investigated as Li-ion-conducting materials and as active materials for anodes of non-aqueous batteries.

Binder formulations based on N-methylpyrrolidone/polyvinylidene fluoride (NMP/PVdF) or water/carboxymethyl cellulose (H2O/CMC) are state of the art in the fabrication of anodes for lithium-ion battery (LIB) applications. However, in combination with metallic lithium these materials tend to degrade. Therefore, for the production and operation of anodes employing metallic lithium particles another binder system, which is flexible, chemically and electrochemically inert, inexpensive, commercially available and, especially for industrial applications, usable within a broad temperature range, is needed. Polyisobutylene (PIB) is able to fulfil these criteria. The advantages of this binder are its inert structure and its solubility in alkanes (e.g. heptane), which are inert against lithium metal, as well. In this work we will introduce heptane/PIB as a binder formulation for the preparation of electrodes from coated lithium powder (CLiP) particles. We demonstrate that CLiP electrodes fabricated with this binder system exhibit better electrochemical performance than electrodes made with NMP/PVdF or tetrahydrofuran (THF)/PVdF formulations. Furthermore, CLiP immersed in heptane/PIB show also better thermal stability compared to CLiP immersed in NMP/PVdF and THF/PVdF.

The article contains sections titled: 1. Introduction 1.1. History 2. Properties 2.1. Physical Properties 2.2. Chemical Properties 3. Occurrence 3.1. Important Lithium Minerals 3.1.1. Lithium Aluminum Silicates 3.1.2. Micas 3.1.3. Lithium Phosphates 3.1.4. Lithium Boron Silicates 3.1.5. Other Lithium Ores 3.2. Lithium Resources and Reserves 3.2.1. Resources in Minerals 3.2.2. Resources in Continental Brines 4. Process Technology 4.1. Concentrate Production 4.2. Mineral Conversion 4.2.1. Acid-Roast Conversion 4.2.2. Lime-Roast Conversion 4.2.3. Ion-Exchange Processes 4.2.4. Clay Roasting Process 4.3. Brine Purification and Concentration 4.4. Lithium Carbonate Production from Brine Concentrate 5. Lithium Metal and Lithium Alloys 5.1. Production of Lithium Metal 5.2. Uses of Lithium Metal 5.3. Lithium Alloys 6. Lithium Compounds 6.1. Inorganic Lithium Compounds and Lithium Salts 6.2. Organolithium Compounds, Lithium Alkylamides, and Lithium Alkoxides 7. Quality Specifications and Analysis 8. Recycling 9. Economic Aspects 10. Toxicology and Occupational Health

Pulmonary arterial hypertension (PAH) is a progressive disorder characterized by remodeling of the pulmonary vasculature and a rise in right ventricular (RV) afterload. The increased RV afterload leads to right ventricular failure (RVF) which is the reason for the high morbidity and mortality in PAH patients. The objective was to evaluate the therapeutic efficacy and antiremodeling potential of the phosphodiesterase type 5 (PDE5) inhibitor sildenafil and the soluble guanylate cyclase stimulator riociguat in a model of pressure overload RV hypertrophy induced by pulmonary artery banding (PAB). Mice subjected to PAB, one week after surgery, were treated with either sildenafil (100 mg/kg/d, n=5), riociguat (30 mg/kg/d, n=5), or vehicle (n=5) for 14 days. RV function and remodeling were assessed by right heart catheterization, magnetic resonance imaging (MRI), and histomorphometry. Both sildenafil and riociguat prevented the deterioration of RV function, as determined by a decrease in RV dilation and restoration of the RV ejection fraction (EF). Although both compounds did not decrease right heart mass and cellular hypertrophy, riociguat prevented RV fibrosis induced by PAB. Both compounds diminished TGF-beta1 induced collagen synthesis of RV cardiac fibroblasts in vitro. Treatment with either riociguat or sildenafil prevented the progression of pressure overload-induced RVF, representing a novel therapeutic approach.

A systematic study has been performed for several chelato-borate complexes by combining electrochemical characterization and ab-initio calculations to reveal whether they are appropriate to be used as electrolyte components in Li-ion batteries. The chelato-borates used in this study are lithium bis(oxalato)borate (LiBOB), lithium salicylatooxalatoborate (LiSOB), lithium bis(salicylato)borate (LiBSB), lithium bis(3-methylsalicylato)borate, lithium bis(5-fluorosalicylato)borate, lithium bis(5-chlorosalicylato)borate, lithium bis(5-bromosalicylato)borate, and lithium bis(3,5-dichlorosalicylato)borate. A graphite electrode is chosen to study the cathodic stability, while LiMn 2 O 4 is selected to estimate the anodic stability limits of these chelato-borates. Additionally, the oxidation potentials of these compounds are predicted by employing density functional theory (DFT) calculations. The CV studies of graphite electrodes in these electrolyte mixtures indicate that irreversible reduction of the oxalato and salicylato groups occurs at 1.6–1.8 and 0.9–1.3 V vs. Li/Li + , respectively. Besides, irreversible oxidation of the bis(salicylato)borate anions between 4.3 and 4.8 V vs. Li/Li + is observed in the CV curves of LiMn 2 O 4 electrodes, depending on the respective ligands around the central boron atom. The theoretical calculations are generally in line with the experimental observations. Furthermore, they help to explain the differences between the oxidation potentials of the anions, which are caused by the different groups that donate the electron and the respective substitution pattern.

Obesity is an increasing health problem worldwide, and nonsurgical strategies to treat obesity have remained rather inefficient. We here show that acute loss of TGF-β-activated kinase 1 (TAK1) in adipocytes results in an increased rate of apoptotic adipocyte death and increased numbers of M2 macrophages in white adipose tissue. Mice with adipocyte-specific TAK1 deficiency have reduced adipocyte numbers and are resistant to obesity induced by a high-fat diet or leptin deficiency. In addition, adipocyte-specific TAK1-deficient mice under a high-fat diet showed increased energy expenditure, which was accompanied by enhanced expression of the uncoupling protein UCP1. Interestingly, acute induction of adipocyte-specific TAK1 deficiency in mice already under a high-fat diet was able to stop further weight gain and improved glucose tolerance. Thus, loss of TAK1 in adipocytes reduces the total number of adipocytes, increases browning of white adipose tissue, and may be an attractive strategy to treat obesity, obesity-dependent diabetes, and other associated complications.

The supersilylated ethene trans-(tBu3Si)HC=CH(SitBu3) (triclinic, P ī) is accessible from the reaction of tBu3SiCHBr2 with nBuLi at −78 °C in THF or Et2 O. The reaction of Li(H2NCH2CH2NH2)C≡CH with tBu3SiBr leads to the formation of (tBu3Si)C≡CH and (tBu3Si)C≡C(SitBu3). X-Ray quality crystals of (tBu3Si)C≡C(SitBu3) (triclinic, P ī) were obtained by recrystallization from hexane. In contrast to the structures of the disilane tBu3Si-SitBu3 and the disiloxane tBu3Si-O-SitBu3, the sterically crowded ethene trans-(tBu3Si)HC=CH(SitBu3) and ethyne (tBu3Si)C≡C(SitBu3) feature dihedral angles of 60° in the solid-state structures

The film formation behaviour of lithium bis(oxalato)borate (LiBOB), a new electrolyte salt for lithium batteries, on graphite, carbon black and lithium titanate is reported. LiBOB is actively involved in the formation of the solid electrolyte interphase (SEI) at the anode. Part of this formation is an irreversible reductive reaction which takes place at potentials of around 1.75 V vs Li/Li+ and contributes to the irreversible capacity of anode materials in the first cycle. Carbon black interacts strongly with LiBOB-based electrolytes, which results in strong film formation and loss of electronic conductivity within the composite electrode. In LiBOB-based electrolytes the electrode kinetics increase in the order: carbon black << fine particulate graphite ~ metal powder, due to decreased film formation of the conductive additive. The influence of various solvents, surfactant additives, and potential impurities was also studied.

Lithium bis(oxalato)borate (LiBOB), a new electrolyte salt for lithium batteries, is actively involved in the formation of the solid electrolyte interphase (SEI) at the anode. Part of this formation is an irreversible reductive reaction taking place at potentials of around 1.75 V versus Li/Li+ and contributing to the irreversible capacity of anode materials in the first cycle. Cyclic voltammetry has been performed on several carbon materials as well as on Li4Ti5O12 and pre-treated glassy carbon electrodes in order to achieve a better understanding of the underlying processes. It is found that the intensity of the 1.75 V peak depends on the BET specific surface area and the surface chemistry of the active material and increases with the amount of oxygen-containing surface functionalities. It is not specific to carbonaceous materials but is also observed on carbon-free anodes like Li4Ti5O12. In addition, the effect of several potential impurities and of film-forming additives on the filming behaviour of LiBOB-containing electrolytes has been investigated.

(tert-Butylimino)(2,2,6,6-tetramethylpiperidino)borane (1) is a highly reactive species. Its B≡N triple bond inserts into the B−H bond of boranes, R2BH, generating diborylamines of the type tmp−BH−NtBu−BR2 (tmp = 2,2,6,6-tetramethylpiperidino; R = H, Cl, Br, or organyl). Thexylborane reacts analogously, but only one of its two B−H bonds is used for the hydroboration of 1. However, dihaloboranes HB(Hal)2−SMe2 (Hal = Cl, Br) give B-haloboration products tmp−B(Hal)−NtBu−BH(Hal), while reactions with H2B(Hal)−SMe2 produce a mixture of two isomers by competing hydroboration and haloboration reactions. Tmp−BH−NtBu−AlH2 was obtained from 1 and AlH3−NMe3. It is a dimer in the solid state with pentacoordinate Al atoms and AlH2Al bridges. Hydrosilylation of 1 was achieved with Me2SiHCl, SiHCl3 or Ph2SiH2 to give the N-silyl-substituted diaminoboranes tmp-BH-NtBu−SiX3−nRn. Me3SnH and Bu3SnH behave similarly, giving the corresponding N-stannylated diaminoboranes. However, when Ph3SnH was treated with 1, the stannylborane tmp−B(SnPh3)−NHtBu was formed showing an umpolung of the hydrostannylation. Organyllithium compounds provide access to N-lithiodiaminoboranes of the type tmp−BR−NtBu−Li. The stability of these compounds depends on the substituent R. The least stable compound was the B−tBu derivative followed by the B-methyl compound. However, in the presence of TMEDA tmp−BMe−NtBu−Li is sufficiently stable to allow reactions, e.g. with B-chlorocatecholborane, to produce tmp−BMe−NtBu−BO2C6H4. The most stable lithium compound so far is tmp−BPh−NtBu−Li−OEt2, whose structure has been determined by X-ray crystallography. MgBu2 behaves like LiR and both of its Mg−C bonds can be used for the insertion reaction. The same is also true of ZnMe2. In contrast, at ambient temperature, only one of the E−C bonds of triorganylalanes, triorganylgallanes and InPh3 is used for the insertion reaction. In the solid state, most of the new compounds show a weak to strong coordinate bond between the electrophilic centre (Li, Mg, Zn, Cd, B, Al, Ga and In) and the nitrogen atom of the tmp group which generates a four-membered ring. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

The conversion of three equivalents of anhydrous oxalic acid with phosphorus pentachloride yields tris(oxalato)phosphorus acid 1, which crystallizes from diethyl ether solutions as protonated diethyl ether complex [(Et2O)2H](+)[P(C2O3)3)]-. The superacidic compound can be used as catalyst for Friedel-Crafts-type reactions. Upon neutralization with lithium hydride, the lithium salt Li[P(C2O3)3] 2 is obtained, which is highly soluble in aprotic solvents and which exhibits a wide voltage window. Thus, the lithium compound is a promising candidate as electrolyte for high performance non-aqueous batteries.

The aminoiminoborane tmp-B=NCMe3 (1) adds to TiBr4 or ZrCl4 in a 1:1 ratio while PdCl2 adds 1 in a 1:2 ratio. In these new compounds the NBN unit is almost linear and the configuration corresponds to an allene. On the other hand 1 and Ti(OR)4 compounds and Ti(NMe2)4 give N metallated diaminoboranes tmp-B(X)-NCMe3EX3 (X = OR, NMe2). Mixed compounds Ti(OR)3-nXn lead to diaminoboranes with BOR groups while the TiCl bond inserts into the B = N bond of 1 to produce tmp-BNMe2-NCMe3TiCl3. Hydrolysis of this compound leads to a spirocyclic dititanoxane with a short linear Ti-O-Ti bond and pentacoordinated Ti centers carrying two Cl atoms each. Spirocycles with a BN2E (E = Ti, Nb, Ta, Pd) unit are formed when 1 is allowed to react with TiCl4, NbCl5, TaCl5 and PdCl2. The palladium compound 16 is dimeric, and dimerization occurs via Pd-Cl bridges. The aminoiminoborane tmp-B=NC6H3-2,6-iPr2 reacts with the titanium compounds in the same manner as 1, however without formation of spirocycles.

Background Receptors for the natriuretic peptides (NPs) ANP, BNP and CNP are highly expressed in lung, suggesting that this organ is an important physiological target for NP signalling. By stimulating vasoand bronchodilation and inhibiting cell proliferation and fibrotic processes, NPs may have therapeutic potential in various lung diseases. Mechanisms responsible for the relatively short half-life (few min) of NPs and the control of their local concentrations include (i) receptor-mediated internalization by the so called clearance receptor (NPR-C) and (ii) degradation by a membrane metalloprotease, called neutral endopeptidase (NEP) or neprilysin [1]. The velocity of peptide degradation/inactivation differs between ANP, BNP and CNP. Interestingly, cleavage of NPs by insulindegrading enzyme (IDE) [2] may have a particular role in NP signalling by generating peptide fragments that are hyperactive in receptor stimulation [3]. The physiological significance of NEP was supported by several studies in rodents showing that NEP inhibition leads to increased NP concentrations and activity. Moreover, we found that NEP inhibition is necessary and sufficient for detection of GC-A and GC-B by affinity labelling experiments with radioactive ANP or CNP in mouse and rat lung membrane preparations. Analogous assays, however, failed to label these receptors in human lung membranes, suggesting potent NP-degrading activity of NEP inhibitor-insensitive proteases. Methods and results ANP degradation by lung membranes in either the absence or presence of NEP inhibitors was analyzed by thin-layer-chromatography and mass spectrometry [2]. We found that NEP inhibition strongly reduces ANP degradation by rat and mouse but not human membranes. ANP-degrading activity in human lung membranes under conditions of NEP inhibition was very potent and even detectable with 1 ng of membrane protein. Like ANP, CNP was rapidly hydrolyzed. In both peptides, initial cleavage occurred at the same position within the conserved peptide ring structure being essential for biological activity. A second cleavage each was localized to the amino-terminus (behind Arg-4 or Lys-4, respectively). The cleavage sites are unrelated to those by NEP and IDE and indicate trypsin-like enzyme activity. Unlike ANP and CNP, BNP is a poor substrate and shows a completely different and complex cleavage pattern after prolonged incubation. The NEP inhibitor-insensitive protease was also detectable, albeit at much lower levels, in membranes from human aorta and mesenteric arteries, but not at all in placenta. Studies with various protease inhibitors revealed that leupeptin exposure potently inhibits NP degradation by this activity.

Background: Right ventricular (RV) pressure overload causes RV remodeling. Impaired NO/cGMP signaling is involved in the pathogenesis of LV hypertrophy. We assessed the effects of the soluble guanylate cyclase (sGC) stimulator BAY 41-8543, the PDE5 inhibitor sildenafil, and combination treatment on RV function and RVH in an animal model of chronic pressure-overload. Methods: RVH was induced by pulmonary artery banding (PAB) in mice. Treatment started 7 days after surgery for 14 days, after which RV morphology and function were studied using Magnetic Resonance Imaging. Fibrosis was assessed by histology. Results: PAB led to RV dysfunction (decreased RV stroke volume (40.5 vs. 23.0ml [Sham vs. PAB]) and decreased RV ejection fraction (70.0 vs. 43.0%)). Treatment with sildenafil did not change RV function, whilst BAY 41-8543 and combination treatment led to significant improvements (RV stroke volume: 23.0 vs. 27.3 vs. 32.1 vs. 31.8; RV ejection fraction: 43.3 vs. 54.1 vs. 55.7 vs. 63.8 [all values as%; placebo vs. sildenafil vs. BAY 41-8543 vs. combination treatment]). PAB mice showed an increased RV/(LV-S) ratio (0.25 vs. 0.39). Drug treatment had no effects on RV/(LV+S) ratio. PAB mice displayed an increased collagen content; sildenafil had no effects on collagen content, whereas BAY 41-8543 and combination treatment both decreased collagen content (7.6 vs. 1.2 vs. 8.8 vs. 3.3 vs. 3.3 [all values as%; placebo vs. sham vs. sildenafil vs. BAY 41-8543 vs. combination treatment]). Conclusions: Even though none of the treatments led to significant changes in RV mass, BAY 41-8543 and combination treatment significantly improved RV function, accompanied by decreased fibrosis.

Contributions to the Chemistry of Boron, 211[1]. — On the Formation of Boron-Germanium Bonds with Dimethylgermylene 2-(Dimethylgermyl)-1,3,2-benzodioxaborole (3) is formed by insertion of dimethylgermylene into the BH bond of catechol borane (2). According to the same principle, the trigermylborane 5 is obtained by insertion of three Me2Ge units into the BCl bond of chloro(2,2,6,6-tetramethylpiperidino)borane (4). Me2Ge reacts with 9-fluorenylidene(tetramethylpiperidino)-borane 8 to yield the trigermaborolane 10, which is characterized by an X-ray structure analysis.

Solutions of GaCl3 in various ethers have been studied by 71Ga NMR spectroscopy. σ71Ga data indicate that the predominant species in diethylether and tetrahydrofuran solutions are GaCl3 · O(C2H5)2 and GaCl3. 2OC4H8, respectively. However, in monoglyme solution dissociation occurs and the product crystallizing from the solution is [cis-GaCl2(monoglyme)2]GaCl4 as demonstrated by an X-ray structure determination of the solvate GaCl3 · monoglyme.

The crystal structure of the title salt, [Li(CH3CN)4][B(NCS)4], is composed of discrete cations and anions. Both the Li and B atoms show a tetra-hedral coordination by four equal ligands. The aceto-nitrile and iso-thio-cyanate ligands are linear. The bond angles at the B atom are close to the ideal tetra-hedral value [108.92 (18)-109.94 (16)°], but the bond angles at the Li atom show larger deviations [106.15 (17)-113.70 (17)°].

P79 [1] was published in error and the correct text follows: Background Right heart failure is a prevalent mechanism of cardiovascular collapse and distinctly different from left heart failure. Afterload reduction has been the main focus to treat right ventricular (RV) dysfunction, but it cannot be achieved in many cases. A new strategy is to directly target increased RV hypertrophy. Pulmonary artery banding (PAB) is used to induce the RV hypertrophy, without any changes in the pulmonary vasculature. The nitric oxide (NO) pathway was shown to be crucially involved in the development of left ventricular hypertrophy. In this study we assessed the effects of the sGC stimulator BAY 41-8543, the PDE5 inhibitor sildenafil, and combination treatment on RV function and RV hypertrophy.

A few compounds composed of nitrogen, hydrogen, and noble gases are known. The major portion of these compounds are van der Waals complexes between ammonia and a noble gas, such as NH3·He, NH3·Ar, or NH3·Kr. A description of these complexes between ammonia and noble gas is beyond the scope of the present volume.

Neither the cyclic nor the acyclic isomers of N5H have been observed experimentally; only organic derivatives of cyclopentazadiene, c-N5H, are known, but their thermal stability is low. The acyclic isomers of N5H are supposed to consist of a double-bonded N2 unit with a hydrogen and an N3 substituent. Each of the (Z) and (E) isomers forms an s-cis or s-trans conformer depending on the spatial arrangement of the approximately linear N3 unit with respect to the N-N double bond. An ab initio SCF MO calculation at the STO-3G level showed that cyclopentazadiene is the most stable isomer of N5H, followed by the (E) s-trans isomer of acyclic N5H and the (Z) s-trans, the (E) s-cis, and the (Z) s-cis isomers. The decomposition to HN3 and N2 is exothermal for all isomers of N5H. A mutual conversion between the (Z) and (E) isomers is predicted not to occur [1].

The potential use of lithium bis(oxalato)borate (LiBOB) as electrolyte salt or additive for lithium-ion batteries has been investigated. The electrochemical performances of LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) and graphite in different electrolyte formulations were studied by galvanostatic techniques and cyclic voltammetry. Differential scanning calorimetry (DSC)/thermal gravimetry (TG), coupled with mass spectrometry, was employed in studying the thermal behavior of charged electrodes in the presence of an electrolyte. The addition of 2 wt % LiBOB to the state-of-the-art LiPF 6 electrolytes suffices to form a stable solid electrolyte interface film, thus protecting the graphite from partial exfoliation. The LiBOB graphite cells exhibited a much lower irreversible capacity in the first cycle in comparison with the pure LiPF 6 electrolyte. NCA has a better cycling stability in LiBOB when compared to the LiPF 6 electrolytes. Also, the discharge capacities obtained at different C-rates between C/5 and 5C were superior to those obtained in LiPF 6 if charging at a C/5 rate. NCA/graphite complete cells in LiBOB cycled with coulombic efficiencies comparable to the state-of-the-art LiPF 6 electrolytes. The DSC/TG measurements showed that LiBOB significantly improves the thermal stability of the graphite in the PC-containing electrolytes. LiBOB shifts the oxygen release from the NCA layered structure to much higher temperatures in comparison with the LiPF 6 electrolyte.

The Karl Fischer titration is the standard method for the determination of the water content in many materials. However, in particular cases, unwanted side reactions occur which leads to unacceptably large errors. We present here an nuclear magnetron resonance (NMR)-based method for the determination of trace impurities of water in a salt recently developed for lithium ion cells, i.e., lithium bis[1,2-oxalato(2-)-O,O']borate (LiBOB). The method, which may be applied to many lithium salts used in batteries, is able to determine traces of water in the salt down to ∼6 ppm. Errors depend strongly on the salt studied. Deviations from expected values obtained by standard addition were 28% for LiBOB, 4% for LiPF 6 , and 6% for LiClO 4 . Using the error propagation law, we estimated an overall error of about 10%.

[2+2]-Cycloadditions of 9-Fluorenylidentetramethylpiperidinoboranes have been studied with selected olefines, acetylenes and iminoboranes. No reactions with olefines were observed. While propiolic methylester reacts exclusively at the carbonyl bond producing the oxaboretane 5, alkines such as diethylamino-alkines, cyclo-octine and phenylacetylene provide access to the'1,2-dihydroboretenes 6, 3 and 2. Tetramethylpiperidinoiminoboranes make 1.2.4-azadiboretidines 7 available. 6a and 7a contain a folded four-membered ring as shown by X-ray structure analysis. There is only a weak 1,3-intraannular interaction due to BN-;r-bonding of the boron atoms with their exocyclic amino group.

CO2, COS, CS2 und CSe2 reagieren mit dem Aminoiminoboran 1 unter [2 + 2]-Cycloaddition zu den Azaboretidinen 2–5. Diese zerfallen thermisch oder photolytisch unter Abspaltung von (CH3)3CN C E′ (E′ = O, S, Se) und Bildung der dimeren (Tetramethyl-piperidino)borchalkogenide 7–9. Die Rontgenstrukturanalyse der schwefelhaltigen Heterocyclen 4 und 8 zeigt planare Vierringe auf. In 4 bildet das C2N-Strukturelement der Tetramethylpiperidino-Gruppe mit der Vierring-Ebene einen Winkel von 72°, in 8 sind die beiden Ebenen dagegen nur um 17° verdrillt. Contributions to the Chemistry of Boron, 159. [2 + 2] Cycloadditions of (tert-Butylimino)(2,2,6,6-tetramethylpiperidino)borane with Carbon Dichalcogenides [2 + 2] Cycloadditions of CO2, COS, CS2, and CSe2 and the aminoiminoborane 1 give access to the azaboretidines 2–5. These decompose thermally or photolytically with formation of (CH3)3CN C E′ (E′ = O, S, Se) and the dimers of the (tetramethylpiperidino)boron chalcogenides 7–9. The X-ray structure analyses of the sulfur containing heterocycles 4 and 8 reveal the presence of planar four-membered rings. The C2N-unit of the tetramethylpiperidino group in 4 approaches a perpendicular arrangement with four-membered ring (interplanar angle 72°), in 8 however, the two planes are twisted to each other by 17° only.

Die rontgenographisch bestimmten Molekulstrukturen des Dioxadiboretans 1 sowie des Diselenadiboretans 3 werden mit dem Dithiadiboretan 2 verglichen. Alle drei Vierringe besitzen ein kristallographisch bedingtes Inversionszentrum. Das Chalcogen beeinflust die BN-Bindungslange praktisch nicht; ferner sprechen auch die Ringinnenwinkel kaum auf eine Anderung des Chalcogen-Atoms an. Dies legt nahe, das die elektronische Absattigung der Bor-Atome weitgehend von der BN-Bindung bestimmt wird. Der B … B-Abstand in 1 ist nur um ≈10% groser als die BB-Einfachbindung. Contributions to the Chemistry of Boron, 171. Crystal and Molecular Structure of 2,4-Bis(2,2,6,6-tetramethylpiperidino)-1,3,2,4-dichalcogendiboretanes The molecular structure of the dioxadiboretane 1 and the diselenadiboretane 3, as determined by X-ray structure analysis, is compared with the structure of the dithiadiboretane 2. All three four-membered ring systems possess a crystallographically imposed center of inversion, and are therefore planar. The group VI atom has no marked influence on the BN bond length; also, the internal ring angles are not affected by a change of these atoms. This indicates that the boron atoms are electronically saturated via the BN bonds. The intraannular B … B distance exceeds the BB single bond length by approximately 10%.

(tert-Butylimino)(2,2,6,6-tetramethylpiperidino)borane (1) reacts with Cr(CO)6 under photolytic conditions producing pentacarbonylmetal complexes 2. The M(CO)5 fragment coordinates to the tert-butylimino group. The X-ray structure analysis of 2a shows an allene type structure with two distinctly different BN bonds (1.29, 1.36 A) and a long CrN bond (2.22 A).