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Während die Zugfestigkeit im Fokus der Forschung am Werkstoff Carbonbeton steht, wurde die Tragfähigkeit des Materials unter Druck bisher kaum untersucht. Aufbauend auf ersten Erkenntnissen zur einaxialen Druckfestigkeit von Carbonbeton werden im Rahmen dieses Projekts scheibenförmige Prüfkörper aus Carbonbeton mit einer kombinierten Einwirkung aus Druck und zusätzlich wirkenden Querdruck- und Querzugbelastungen betrachtet. Dieser Beitrag stellt die ersten Ergebnisse der zweiaxialen Druckbelastungen vor und gibt einen Ausblick auf weiterführende Untersuchungen im Projekt.

To provide healthcare professionals with a comprehensive assessment of donepezil 23 mg and its role in treating Alzheimer's disease (AD), the Donepezil 23 mg Expert Working Group (EWG) convened in June 2011 to critically evaluate the clinical trial database for this higher dose formulation and the members' clinical experience with its use. Discussions were based on a large, 6‐month, phase 3 clinical trial in patients with moderate to severe AD that compared continuing donepezil 10 mg/day versus switching to 23 mg/day. In this trial, donepezil 23 mg/day demonstrated significantly greater cognitive benefits (mean change in Severe Impairment Battery score, 2.11 points; P

Objectives We investigated the effect of oral verapamil on clinical outcome and angiographic restenosis after percutaneous coronary intervention (PCI). Background Thus far, there is no established systemic pharmacologic approach for the prevention of restenosis after PCIs. Five small studies reported encouraging results for calcium channel blockers. Methods Our randomized double-blind trial included 700 consecutive patients with successful PCI of a native coronary artery. Patients received the calcium channel blocker verapamil, 240 mg twice daily for six months, or placebo. Primary clinical end point was the composite rate of death, myocardial infarction, and target vessel revascularization (TVR) during one-year follow-up; the angiographic end point was late lumen loss at the six-month follow-up angiography. Results We obtained complete clinical follow-up in 95% of the patients, and scheduled angiography was performed in 94%. The proportion of patients treated with stents was 83%. The primary clinical end point was reached in 67 (19.3%) patients on verapamil and in 103 (29.3%) patients on placebo (relative risk [RR] 0.66 [95% confidence interval (CI) 0.48 to 0.89]; p = 0.002). This difference between the groups was driven by TVR (17.5% with verapamil vs. 26.2% with placebo; RR 0.67 [95% CI 0.49 to 0.93]; p = 0.006). Late lumen loss was 0.74 ± 0.70 mm with verapamil and 0.81 ± 0.75 mm with placebo (p = 0.11). Compared with placebo, verapamil reduced the rate of restenosis ≥75% (7.8% vs. 13.7%; RR 0.57 [95% CI 0.35 to 0.92]; p = 0.014). Conclusions Verapamil compared with placebo improves long-term clinical outcome after PCI of native coronary arteries by reducing the need for TVR. This was caused by a reduction in the rate of high-grade restenosis.

A 27-year-old worker in a metal processing factory was found dead in a basin, sitting in a solution containing potassium dicyano argentate, potassium cyanide, master batch and brightener 'Elfit 73'. The worker was wearing an acid-resisting overall, rubber boots and a simple dust respirator. While the cyanide concentration in the stomach contents was only 0.05 microg/ml, it was 7.7 microg/g in the lung tissue, 6.3 microg/ml in the heart blood and 31 microg/ml in the femoral vein blood. The different concentrations suggest an initial lethal inhalation of cyanide and an extensive post-mortem diffusion of cyanide through primarily non-injured skin of buttocks and legs. The possibility of a post-mortem cyanide diffusion bars from concluding a vital sign from a high cyanide concentration in a blood sample of one single body site.

Two cases of self-mutilation with needles are reported. One of the deceased suffered from chronic schizophrenia and committed suicide by plastic bag suffocation. At autopsy several needles were detected grown into the connective tissue of chest or abdominal organs. In the other case a knitting needle was used for repeated manipulations at the forehead leading to a defect of the skin and the skull. At least one vessel was injured leading to an extensive haemorrhage in the left hemisphere of the brain. The forensic and etiologic aspects of the cases are discussed.

A total of 59 penetrating contact shot wounds to the head caused by handguns was investigated and a comparison was made between the magnitude and the number of fracture lines at the entrance and exist site of the vault and at the base of the skull. It was noted that in approximately 50% of the cases the extent of fractures at the entrance site exceeded those at the exit wound while in the remaining individuals no relevant differences or even greater exit fractures were found. Furthermore, no close correlation between the fracture patterns of the vault and at the base of the skull occurred indicating that differences in the magnitude and the number of entrance or exit fracture lines cannot provide reliable information on direction of fire. Additionally, no further conclusions on the gun used can be drawn from differences in the entrance and exit fracture patterns. It can only be assumed that the absence of fractures in the cranial fossae points to the use of small calibre handguns (or = 7.65 mm) while a fragmentation of the skull can as a rule be expected after shots from guns with larger calibres (7.65 mm).

Self-injection of toxic substances is a rare method of suicide. Since only case reports exist in the forensic literature, an evaluation of the autopsy reports of the Munich Department of Legal Medicine in the period 1976-1994 was performed including 36 suicides and seven homicides due to injection of toxic agents. The majority of the decreased were physicians nurses or, in cases of homicidal intoxication relatives. The commonly used substances were anaesthetic drugs.

The immunohistochemical detection of stringlike ramifying structures positive for fibronectin in wounds aged at least a few minutes provides valuable information on the vitality of skin lesions even before the appearance of neutrophilic granulocytes. Positive reactions for tenascin or collagen type III indicate postinfliction intervals of at least 2-3 days, whereas vital reactions for collagen type V or VI occur earliest 3 days after wounding. Collagen type I appears as spotlike fibroblast-associated reaction products in injuries aged 4 days or more, while typical stringlike ramifying fibers indicate a postinfliction interval of at least 5-6 days. Fibroblasts positively staining for laminin or heparan sulfate proteoglycan can be detected in wounds with a survival time of approximately 1.5 days or more and collagen type-IV-positive cells occur earliest 4 days after wounding, followed by alpha-smooth muscle actin expressing fibroblasts after 5 days or more. Basement membrane fragments positive for laminin, heparan sulfate proteoglycan, or collagen type IV or VII indicate a wound age of at least 4 days, and a complete restitution of the epidermal basement membrane in (surgical) wounds can be observed earliest 8 days after wound infliction. Positively reacting basement membrane fragments are absent up to a wound age of < 13 days, and the evidence of an incompletely rebuilt basement membrane indicates a postinfliction interval of less than approximately 22 days. A continuous staining of the basal cells of the newly formed epidermis for cytokeratin 5 occurs earliest 13 days after wounding, and the absence of a complete staining provides information on a wound age of < 24 days.

A total of 117 vital skin wounds (post infliction intervals between a few seconds and 7 months), 20 postmortem wounds and skin specimens with beginning or advanced signs of putrefaction were investigated. Different markers for macrophage maturation (27 E 10, RM 3/1, 25 F 9, G 16/1) were analyzed by immunohistochemistry. The early stage inflammation marker 27 E 10 stained macrophages, but also monocytes and neutrophilic granulocytes localized in blood vessels or bleeding induced postmortem and therefore provided no further information for a forensic wound age estimation in comparison to the routine histological detection of macrophages. The antigens recognized by the RM 3/1- (intermediate stage inflammation marker) and 25 F 9-antibodies (late stage inflammation marker) were expressed exclusively by histiocytes and inflammatory cells that had migrated from the blood vessels as part of the acute inflammatory response associated with an intravital reaction. The morphometrical analysis revealed positive results (defined as at least a two-fold increase in number in 2 or more microscope fields when compared to the maximum value of histiocytes found in uninjured skin) for the RM 3/1- or 25 F 9-antibody earliest in wounds aged 7 or 11 days, respectively. Similarly to the 25 F 9-antibody, the chronic stage inflammation marker (G 16/1) reacted with a macrophage subpopulation first detectable 12 days after wounding but showed positive results in a comparably reduced percentage of cases. On the other hand, this marker did not stain a relevant number of resident macrophages thus facilitating the evaluation of the specimens. The markers 27 E 10, RM 3/1 and 25 F 9 are also useful for the evaluation of slightly - even though the staining intensity was considerably reduced - but not advanced putrefied skin. Therefore, the immunohistochemical analysis of the corresponding antigens can possibly contribute to an age estimation of wounds with advanced post infliction intervals obtained from corpses with longer - but limited - postmortem intervals.

Tumour markers hold a great relevance in the diagnosis and the follow-up treatment of different kinds of human carcinoma. Although head and neck cancer occurs frequently, there is still lack of appropriate tumour markers. Our investigation on the expression of sialyl Lewis A (CA19-9) in laryngeal carcinomas, consists of systematical analysis of oncofetal carbohydrates and of galectins 1 and 3 in different normal and malignant tissues of the aerodigestive tract.Paraffin-embedded sections of normal tongue, vocal cord, larynx, pharynx and epiglottis, representing normal control tissue and laryngeal cancer tissue were incubated with monoclonal antibodies against sialyl Lewis A and X (sLeA and X), Lewis Y (LeY), the Thomsen-Friedenreich (TF) antigen and galectin 1 and 3 (Gal-1 and -3). A staining reaction was carried out with ABC-peroxidase and diaminobenzidine (DAB). Tissue of breast cancer was used as a positive control. Mouse IgM, as isotype control antibody, was used as a negative control. Semi quantitative evaluation was carried out double-blinded, by two independent investigators, including a pathologist.Squamous epithelia of all investigated normal tissues of the aerodigestive tract show nearly the same pattern. Most impressive findings are the very weak expression of Gal-1 and the total absence of the TF antigen. Laryngeal cancer reveals high amounts of sLeA, Gal-1 and the TF antigen.On the basis of our findings in normal tissue of the aeradigestive tract, these three markers qualified as potential tumour markers for carcinoma of the aerodigestive tract. In particular, the high expression of TF in cancer tissue and its absence from the normal tissue is promising for its establishment as a new tumour marker in this field.

A morphometrical analysis was performed to elucidate the significance of pulmonary polynuclear giant cells as a histological sign of asphyxiation. A total of 13 cases of homicidal strangulation of throttling, 8 cases of traumatic asphyxia due to chest compression and 10 control cases (cause of death: severe head injury, no signs of aspiration or other relevant pulmonary alterations, smokers and non-smokers) were investigated. The number of alveolar macrophages containing 1 or 2 nuclei and of polynuclear giant cells per microscopic field (0.000025 cm2) was estimated and a statistical evaluation was carried out. A considerable individual variation was observed in all groups with a tendency to higher numbers of cells in cases of smokers or advanced individual age. However, no significant differences were detectable in the content of alveolar macrophages and in particular of polynuclear giant cells between the asphyxiated individuals and the controls. Since polynuclear giant cells occurred in similar amounts in healthy, functionally normal lungs of non-asphyxiated individuals, the detection of such cells cannot be regarded as a reliable indicator for asphyxiation.

Sixty-nine healthy normals from the 3rd to the 6th decade were stressed to exhaustion by means of a cardiopulmonary exercise test on a bicycle ergometer. Peak VO2, VCO2 and ventilation differed significantly between the four decades: peak VO2 (mean +/- SD) was 3,393 +/- 516; 3,061 +/- 444; 2,817 +/- 801 and 2,589 +/- 687 ml/min (p0.001). The mean value for respiratory gas exchange ratio (R) at ventilatory threshold (VT) was 0.86 and for ventilatory equivalent O2 (EqO2) 0.24. Mean VO2 at VT was 1,662 +/- 521; 1,462 +/- 308; 1,474 +/- 559 and 1,268 +/- 232 ml/min (p0.05). The VO2 of the four age groups at VT was between 47 and 49% of peak VO2 (n.s.), and both parameters correlated significantly (r = 0.67, p0.001). The average increase of VO2 in relation to work rate (ml/W/min) was 11.5 +/- 1.2 for the total exercise and was below VT lower (9.4 +/- 1.9) than above VT (12.9 +/- 1.2) (p0.001).

In the present study, we examined the number of alveolar macrophages in lung tissue from 17 cases of fresh water drowning, 22 cases of acute death and 6 cases of lung emphysema. When counting only the number of alveolar macrophages per alveolus without consideration of the alveolar size we found no relevant differences between the groups investigated. To exclude any influence of the alveolar size on the results the surface density of the alveolar macrophages and interstitial tissue was estimated and compared in the different groups. In cases of drowning, the lungs showed significantly lower values in both categories. The ratio of 'alveolar macrophages/interstitial tissue' was also reduced in cases of drowning in comparison to the other groups, however, without significant differences. These morphometrical results characterizing the 'emphysema aquosum' with almost 'empty' and dilated alveoli could be explained by a wash-out effect of the drowning fluid leading to a partial removal of the macrophages from the alveoli. This hypothesis was confirmed by the detection of alveolar macrophages in the drowning froth by immunohistochemical analysis. Even though alveolar macrophages were unambiguously identified in advanced putrefied lungs in HE-stained sections as well as by immunohistochemical staining, an estimation of the number of these cells cannot provide further information for the diagnosis of drowning in putrefied corpses due to the autolytic destruction of the lung architecture providing no reliable values.

A total of 638 drug death autopsy cases in southern Bavaria from 1981 to 1992 were analysed, including epidemiological and toxicological investigations. The rate of HIV infections decreased during the last few years. Cocaine does not (yet) play a major role. Suicide rates are high. Heroin intoxications are the most frequent cause of death, mostly in combination with other drugs and alcohol. In 1992 we observed a sharp increase of the number of deaths associated with dihydrocodeine abuse. This seems to be a local phenomenon and has to be explained by uncritical and uncontrolled prescription of large amounts of this opiate by individual physicians.

The title compounds have been prepared by reacting a Cp′CrCl2 or a (η3-allyl)2CrCl species with either an allylmagnesium halide or a substituted cyclopentadienyllithium derivative. The compounds react further at room temperature to give the dinuclear species [Cp′(μ-η3-allyl)Cr]2, and with P-donor ligands with reductive coupling of the allyl groups to give Cp′(η2,η2-1,5-hexadiene)CrPR3 species. Diene exchange is observed upon reacting the hexadiene compounds with butadiene or cyclohexadiene. The crystal structures of [Cp(μ-η3-C3H5)Cr]2, [(η5-indenyl)(μ-η3-C3H5)Cr]5)Cr2, (η5-indenyl) (η2,η2-1,5-hexadiene)CrP(OMe)3 and three compounds containing a 1,3-diene, viz. Cp(η4-1,3-C4H6)CrPMe3, (η5-Me5C5)(η4-1,3-C4H6)CrCO and Cp(η4-1,3-cyclohexadiene)CrP(OMe)3 have been established by X-ray diffraction.

The time-dependent reepithelialization of 55 human surgical skin wounds with a wound age between 8h and more than 2 months was investigated by the immunohistochemical localization of cytokeratins 5 and 13. A complete, rebuilt epidermal layer over the wound area was first detectable in a 5-day-old wound, while all wounds of more than 18 days duration contained a completely reepithelialized wound area. Between 5 and 18 days the basal layer of keratinocytes showed — in contrast to normal skin — only some cells positive for cytokeratin 5. In some, but not all lesions with a wound age of 13 days or more, a basal cell layer completely staining for cytokeratin 5 was demonstrable. This staining pattern was found in all skin wounds with a wound age of more than 23 days. The immunohistochemical detection of cytokeratin 13 which can be observed regularly in non-cornifying squamous epithelia provides no information for the time-estimation of human skin wounds, since no significant temporary expression of this polypeptide seems to occur during the healing of human skin wounds.

This study was performed to prove whether the detection of polynuclear giant cells in lungs is useful for the diagnosis of asphyxiation due to throttling or strangulation. Therefore, lung specimens of 54 individuals with different natural and unnatural causes of death were investigated. In most lungs examined numerous alveolar macrophages with 1-2 nuclei were found. Polynuclear giant cells, which were arbitrarily defined as alveolar macrophages containing 3 or more nuclei, were observed in all groups investigated except in the cases of hypoxia due to covering the head with plastic bags. Apparent differences between the other groups in particular an increased number in cases of throttling or strangulation, could not be observed. Immunohistochemical investigations confirmed the hypothesis that the observed polynuclear giant cells were derived from alveolar macrophages. The immunohistochemical analysis of the proliferation marker antigen Ki 67 revealed no positive reaction in the nuclei of polynuclear giant cells indicating that these cells had not developed shortly before death by endomitosis as an adaptative change following reduction in oxygen supply. The results provide evidence that the detection of pulmonary polynuclear giant cells cannot be used as a practical indicator for death by asphyxiation due to throttling or strangulation.

More and more car manufacturers are now demanding clear coats with improved scratch resistance from their paint suppliers. Some motor companies have developed their own tests, some have chosen a test developed by a paint supplier and others are still looking for their optimum test. The opinion prevails that there should be one test which covers all aspects of realistic damage. However, microscopic photographs and reflow experiments show that two kinds of scratches occur in reality, abrasive as well as non-abrasive, renewable ones. Different standard clear coat systems have different sensitivities to both scratch types. In the scratch tests the rating of the clear coats is divergent, because the ratio of both sorts of scratches differs. We have developed a set of two tests, where each test mainly generates one scratch type. These tests, together with physico-chemical measurements (glass transition onset temperature T g , laser optical profile scanning, indentation depths) lead to a deeper insight into scratch phenomena. One way to develop a clear coat which is resistant against all kinds of scratching damage is described.

Three isomeric bicyclo[3.2.0]heptadienes 1 – 3 are compared by semiempirical calculations. Experimental attempts directed to the synthesis of derivatives of 1 are described. The synthesis, properties and some reactions of (η51-bicyclo[3.2.0]hepta-1,3-dienyl)(η41-cycloocta-1,5-diene)cobalt(I) (22), including an X-ray crystal structure determination of the reaction product with diphenylethyne, the tetraphenylcyclobutadiene complex 30, are presented.

The crystal and molecular structures of (η 5 -C 5 H 5 )Zr(CH 2 C 6 H 5 )3 ( 2b ) and (η 5 -C 5 H 5 ) 2 Ti(CH 2 C 6 H 5 ) 2 ( 3a ) are reported. Crystals of 2b are trigonal with space group P 3 1 c and cell constants: a = b = 11.427(2) and c = 9.066(1) A. 3a crystallizes in space group Pbca with a = 11.330(1), b = 16.050(3) and c = 20.730(5) A. The two compounds have significantly different MCC angles for the coordinated benzyl ligands. Whereas the benzyl ligands in 3a are σ-bonded to the metal, in 2b they tend towards an η 2 -type of coordination [ZrCC = 94.5(5)°]. 2b , 3a and other structurally characterized benzyl metal complexes indicate that the 13 C NMR chemical shift of the benzyl ipso -C atom is a useful indicator to distinguish between different modes of ligation.

A total of 74 human skin wounds were investigated and collagen types I and VI were localized in the wound area by immunohistochemistry. Collagen type I appeared in the form of ramifying string-like structures after approximately 5–6 days, but positive reactions in the form of a spot-like staining around isolated fibroblasts also occurred in a skin wound aged 4 days. Collagen VI was detectable after a post-infliction interval of at least 3 days showing a strongly positive reacting network associated with fibroblasts in the wound area. Both collagens appeared almost constantly after a wound age of 6–7 clays and could also be found in wounds aged a few months. Therefore, although a positive reaction for collagen type I in the form of string-like and ramifying structures around wound fibroblasts indicates a wound age of at least 5–6 days, a spot-like positive staining for collagen type I cannot exclude a wound age of at least 4 days. A positive staining for collagen type VI represents a post-infliction time of 3 days or more. The almost constant appearance of these collagen types suggests that negative results in a sufficient number of specimens indicate a wound age of less than 6–7 days, but cannot completely exclude longer post-infliction intervals. Since collagen type I and VI are also found in the granulation/scar tissue of lesions with advanced wound age, the immunohistochemical analysis of these proteins provides no further information for an age determination of older skin wounds.

The clinical relevance of the carbohydrate antigen Sialyl Lewis a (SLea) as a serum tumor marker in diagnosis and follow-up treatment is unquestioned in a broad spectra of human carcinomas. Overexpression of this antigen is combined with poor prognosis and malignant relapse. The aim of our study was the systematic investigation of SLea expression in squamous cell carcinoma of the larynx versus normal and phlogistic tissue.Paraffin-embedded sections of normal, phlogistic and squamous cell carcinoma tissue were incubated with a monoclonal antibody against SLea. The staining reaction was performed using ABC-Peroxidase and DAB. As a positive control tissue of breast cancer was used and the negative control was performed with unspecific mouse IgM. Semiquantitative evaluations were carried out double-blinded by two independent investigators, including a pathologist.A very faint expression of SLea (Ca19-9) in normal laryngeal tissue, a moderate upregulation in phlogistic tissue and a dramatic upregulation in some types of squamous cell carcinoma of the larynx were observed. Laryngeal cancer is the most common cancer of the upper aerodigestive tract. Most cases of laryngeal cancer are squamous cell carcinoma and can be classified into: well differentiated (more than 75% keratinization), moderately differentiated (25-75% keratinization), and poorly differentiated (25% keratinisation) carcinomas.The results of this study indicate that SLea is a potential tumor marker in carcinoma of the larynx.

The tissue localization was analysed of collagen X during human fetal and juvenile articular cartilage-bone metamorphosis. This unique collagen type was found in the hypertrophic cartilage zone peri- and extracellularly and in cartilage residues within bone trabeculae. In addition, occasionally a slight intracellular staining reaction was found in prehypertrophic proliferating chondrocytes and in chondrocytes surrounding vascular channels. A slight staining was also seen in the zone of periosteal ossification and occasionally at the transition zone of the perichondrium to resting cartilage. Our data provide evidence that the appearance of collagen X is mainly associated with cartilage hypertrophy, analogous to the reported tissue distribution of this collagen type in animals. In addition, we observed an increased and often "spotty" distribution of collagen X with increasing cartilage "degeneration" associated with the closure of the growth plate. In basal hypertrophic cartilage areas, a co-distribution of collagens II and X was found with very little and "spotty" collagen III. In juvenile cartilage areas around single hypertrophic chondrocytes, co-localization of collagens X and I was also detected.

In 62 human skin wounds (surgical wounds, stab wounds and lacerations after surgical treatment) we analyzed the immunohistochemical localization of collagen IV in the epithelial basement membrane. In 27 of these wounds the distribution of collagen VII, which represents a specific component of the basement membrane of stratified epithelia, was also analyzed. We were able to demonstrate a virtually identical co-distribution of both collagen IV and VII in the wound area with no significant time-dependent differences in the appearance of both collagen types. Fragments of the epithelial basement membrane could be detected in the wound area from as early as 4 days after wounding and after 8 days a complete restitution of the epithelial basement membrane was observed. In all cases with a wound age of more than 21 days the basement membrane was completely reformed over the former lesional area. The period between 8 and 21 days after wounding was characterized by a wide variability ranging from complete restitution to deposition of basement membrane fragments or total lack of the epidermal basement membrane.

Dithiocarboxylic Acids and Derivatives from Carboxylic Esters and Lactones with the Organoboron Sulfide Reagent (9-BBN)2S[1] Bis(1,5-cyclooctanediylboryl) sulfide (1) reacts with carboxylic esters to give the dithiocarboxylic 1,5-cyclooctanediylboryl esters 2a–f in high yields (2a: X-ray crystal structure analysis). Methanolysis of 2a–f leads to the dithiocarboxylic acids 5a–f, which form the corresponding piperidinium salts in the presence of piperidine. When cyclic esters (γ-, δ-lactones) are allowed to react with 1, the boryloxy-substituted dithiocarboxylic 1,5-cyclooctanediylboryl esters 3a–c are obtained.

Crystals of Mn(CH3CONH2)2(HPhPO2)2 are monoclinic, a = 5.668(2), b = 7.500(2), c = 23.104(2) Å, β = 95.52(2)°, Z = 2, space group P21/c, and those of Mn(HPhPO2H)2(HPhPO2)2 are monoclinic, a = 23.281(1), b = 5.508(2), c = 20.5489(6) Å, β = 90.424(4)°, Z = 4, space group C2/c. The structures were solved by heavy-atom methods and were refined by full-matrix least-squares procedures to R = 0.028 and 0.035 for 2081 and 2117 reflections with I ≥ 3σ(I), respectively. Both compounds have structures consisting of polymeric chains propagating along the crystallographic b axis; two phosphinate ligands bridge adjacent manganese atoms forming square planar MO4 units, and six coordination about the metal is achieved by axially O-bonded neutral ligands. Indirect evidence supports similar structures for the other complexes studied here. The complexes are antiferromagnetic and the magnetic susceptibilities have been analyzed according to two Heisenberg models for linear chains. The exchange coupling constants range from −0.30 cm−1 for the acetamide complex to −0.06 cm−1 for the pyridine complex. Magnetostructural correlations involving these complexes and the previously studied Mn(HCONH2)2(HPhPO2)2, reveal that the magnitude of the magnetic coupling is enhanced by symmetrically bridging O—P—O units and short Mn–O–P–O–Mn pathways for exchange. Keywords: polymeric manganese monophenylphosphinates, crystal structures, magnetic properties.

Bis(cyclopentadienyl)methane-Bridged Dinuclear Complexes, IV[1]. — Synthesis, Structure, and Reactivity of Dinuclear Rhodium and Iridium Complexes in the Oxidation State +I and +III with the Bis(cyclopentadienyl)methane Dianion as Bridging Ligand The rhodium compounds [CH2(C5H4)2][Rh(L)(C2H4)]2 (2, 4) were prepared from [RhCl(L)(C2H4)]2 (1, 3) and CH2(C5H4)2Li2 in 92 and 73% yield, respectively. The reaction of 4 with Cl2, Br2, and I2 led to the almost quantitative formation of the dihalogeno derivatives [CH2(C5H4)2][RhX2(PiPr3)]2 (6–8), which on treatment with excess NaBH4 and methanol gave the dihydride [CH2(C5H4)2][RhH2(PiPr3)]2 (10). From [RhCl(C8H14)2]2 (12), PiPr3, and CH2(C5H5)2 the chloro(hydrido)rhodium complex [CH2(C5H4)2][RhH(Cl)(PiPr3)]2 (13) was obtained. Protonation of 10 with CF3CO2H in the presence of NH4PF6 gave the PF6 salt of the hydrido-bridged cation {[CH2(C5H4)2]-[RhH(PiPr3)]2(μ-H)}+ (14) of which the crystal structure was determined. In solution, fluxional behavior of the cation was observed. The dimethyl compound [CH2(C5H4)2][Rh(CH3)2-(PiPr3)]2 (17), prepared from 6, 7, or 8 and LiCH3 or CH3MgI in 80% yield, reacted with CF3CO2H at — 78° C to give the tri-fluoroacetato derivative 18; this on treatment with P(OMe)3 and dmpe formed the dicationic complexes 19 and 20, respectively. The dinuclear iridium compounds [CH2(C5H4)2]-[Ir(olefin)2]2 (26, 27) and [CH2(C5H4)2][Ir(C8H12)]2 (28) were prepared from [IrCl(L)2]2 (23–25) and CH2(C5H4)2Li2 and used for the synthesis of {[CH2(C5H4)2][IrX2]2}n (29, 30). Compounds 29 and 30 served as starting materials for the preparation of the dinuclear derivatives [CH2(C5H4)2][IrX2(L)]2 (31–34) and {[CH2(C5H4)2][IrBr2]2(μ-dipy)} (35) and finally also for the dihydrido complex [CH2(C5H4)2][IrH2(PiPr3)]2 (36).

Organophosphorus Compounds, 511). – Phosphatriafulvenes – Phosphaalkenes with Inverse Electron Density2) Peterson olefination of the sterically hindered cyclopropenones 1 with the lithium phosphides 2 yields the so far unknown phophatriafulvenes 3 and 4, which possess inverse electron densities. They are characterized by transition metal complex formation (→7, 8). Acylation of 3a with the carboxylic acid chlorides 11 leads to a great variety of P-acylphosphatriafulvenes 13a-s. They partly dimerize under formation of the 1,3-diphosphacyclobutanes 13 ⇌ 14.

Synthesis, Structures, and Properties of Cyclothiaselenazenium Cations [[Se2N2S]22+, [XSe2N2S]+, [Se2N2S]2+, [S3SeN5]+as well as Cl2Se2N2S and SeSN2 and SeSN2 ṁ TiCl4 Bis(sulfinylamino)selane (1), prepared from Se2Cl2 and (CH3)3SiNSO, reacts with Lewis acids such as MF5 (M = As, Sb, Nb) and BF3 to form bis(1,3,4,2,5-thiadiselenadiazolium) cations (3) with counter anions AsF-6 (3a), SbF-6 (3b), NbF-6 (3c), BF-4 (3d). Treatment of Se2Cl2 with LiN[Si(CH3)3]2 leads to [(CH3)3Si]2NSexN[Si(CH3)3]2 (x = 1, 2a: 2, 2b). From 2a and 2a and SeCl4 explosive Se4N4 is obtained. Chlorination of 3a and 3c gives [ClSe2N2S]+[MF6]- (M = As, 4a, and Nb, 4c). Analogous bromination of 3a provides [BrSe2N2S]+ [AsF6]- (4b). This type of chlorinated five-membered rings is also obtained directly from 1 and SbCl5 and PCl5 or SeCl4. The products isolated are [ClSe2N2S]+ [SbCl6]- (4d) and [ClSe2N2S]+Cl- (4e). – A covalent species 5, isomeric to 4e, is obtained from 1 and POCl3, and a four-membered ring SeSN2 ṁ TiCl4 (6) from 1 and TiCl4. When 3a or 1 is treated with a two- or threefold excess of AsF5 the stable dication [Se2N2S]2+ (7) is formed. It arises also from 4e and AgAsF6. Attempts to replace TiCl4 in 6 by AsF5 lead to [SeS3N5]+ [AsF6]- (8) with a bicyclic structure for the cation. X-ray structure analyses for 1, 4c, 4d, 4e, 5, and 8 are performed.

The 27Al NMR spectra for a series of aryloxyaluminium compounds [RnAl(OAr)3−n]m (R  methyl, isobutyl; n  0–2; m  1, 2, 3) with various alkyl substituents in the 2 and 6 positions of the phenoxy rings have been measured. The δ(27Al) resonances give an indication of the number of aryloxy ligands and the coordination number of each Al atom. Monomeric R2AlOAr compounds have δ(27Al) resonances around 190 ppm whereas dimeric analogues give signals at 167 ppm. The 27Al NMR resonances for monomeric RAl(OAr)2 are found at ca. 100 ppm while those for [Al(OAr)3]2, where the aluminium atoms are solely bonded to aryloxy groups, lie at ca. 50 ppm. Characteristic shifts of the resonances were also observed for complexes of these compounds with THF, whereby it was found that the resulting change Δδ(27Al) decreases with increasing number of aryloxy ligands. The crystal structures of three selected compounds, 3, 8 and 11, were determined by X-ray crystallography.

The synthesis, spectroscopic characterization, and the X-ray crystal structure determination of tricarbonyl-η6-[1,2-bis(ethylendioxy)cyclobutabenzene]chromium(0) are described. The free enthalpy of activation of the Cr(CO)3 rotation has been determined by variable temperature solid state 13C CP-MAS NMR spectroscopy to be ca. 60kJ/mol.

{Bis[bis(trimethylsilyl)methyl]stannio(II)}bis(η2-ethene)nickel(0) and Related Compounds, Part II The coordinatively unsaturated (16e) (ethene)nickel(0) stannylene complex (C2H4)2Ni=Sn{CH(SiMe3)2}2 (1) reacts with 1,6-heptadiene with preservation of the Ni=Sn bond to yield quantitatively the 1,6-diene derivative (η2,η2-C7H12)Ni=Sn-{CH(SiMe3)2}2 (2). The alkene ligands of both 1 and 2 are readily displaceable. Compounds 1 and 2 react with butadiene at −50°C by a 4-e oxidation of the metal-metal pair Ni(0)/Sn(II) to Ni(II)/Sn(IV) and concomitant reduction of two butadiene molecules to butenediyl moieties to afford stereo-selectively the 16-e complex Ni-cis-{η3(Ni),η1(Sn)-anti-C3H4CH2}2Sn{CH(SiMe3)2}2 (3). Similarly, the reaction of 1 or 2 with isoprene yields regio- and stereoselectively the derivative Ni-cis-{η3(Ni,η1(Sn)-anti-C3(3-Me)H3CH2}2Sn{CH-(SiMe3)2}2 (4). These reactions imply the cleavage of one formal NiSn bond and the formation of two new SnC bonds. Upon reaction of 3 with PMe3 the configuration of the allyl system changes and, again fully stereoselectively, the 18-e addition compound (Me3P)Ni-cis-{η3(Ni),η1(Sn)-syn-C3H4-CH2}2Sn{CH(SiMe3)2}2 (5) is formed. When 5 is treated with BPh3, the phosphane ligand is trapped and, kinetically controlled, Ni-cis-{η3(Ni),η1(Sn)-syn-C3H4CH2}2Sn{CH(SiMe3)2}2 (6) is obtained as a stereoisomer of 3. At 40°C 6 slowly rearranges into the thermodynamically stable stereoisomer Ni-trans-{η3(Ni),η1(Sn)-syn-C3H4CH2}2Sn{CH(SiMe3)2}2 (7). Mild protolysis of 3 with pyridine hydrochloride or hydrobromide affords region and stereoselectively (Me3Si)2CH}2(X)SnNi-(η3-1-MeC3H4)(NC5H5) (X = C1, 8a; Br, 8b). In the course of this protonation reaction one butadiene molecule is eliminated, accompanied by a 2-e reduction of the metal-metal pair Ni(II)/Sn(IV) to Ni(II)/Sn(II) and, at the expense of two SnC bonds, reformation of a NiSn bond. All compounds are isolated in high yield and fully characterized by 1H-, 13C-, and 31P-NMR spectroscopy.

The tricarbonyl(cyclobutabenzene)chromium(O) complexes 12 – 20, have been prepared from the free ligand and triammintricarbonylchromium(O) or hexacarbonylchromium(O). The complexes have been characterized by spectroscopic methods (IR, 1H NMR, 13C NMR) and mass spectrometry, and 1H-NMR signal assignments have been verified by an NOE experiment. Diastereomeric ratios have been determined by 1H NMR and the diastereomers of the 1-methyl derivative 16 separated by HPLC. A crystal-structure analysis is presented for exo;-16. A photochemical ligand exchange takes place in 70% yield for the 1-trimethylsilyl derivative 19. Metalation with n-butyl-lithium/tmeda at –78°C has been observed only for the aromatic and not for the benzylic protons.