bluuebunny/crossref_metadata_2025 huggingface dataset:
Stepwise formation of patterned cell co‐cultures in silicone tubing
Authors: Kaji Hirokazu , Sekine Soichiro , Hashimoto Masahiko , Kawashima Takeaki , Nishizawa Matsuhiko
Published: May 2007

Here, we describe a method for producing patterned cell adhesion inside silicone tubing. A platinum (Pt) needle microelectrode was inserted through the wall of the tubing and an oxidizing agent electrochemically generated at the inserted electrode. This agent caused local detachment of the anti‐biofouling heparin layer from the inner surface of the tubing. The cell‐adhesive protein fibronectin selectively adsorbed onto the newly exposed surface, making it possible to initiate a localized cell culture. The electrode could be readily set in place without breaking the tubular structure and, importantly, almost no culture solution leaked from the electrode insertion site after the electrode was removed. Ionic adsorption of poly‐L‐lysine at the tubular region retaining a heparin coating was used to switch the heparin surface from cell‐repellent to cell‐adhesive, thereby facilitating the adhesion of a second cell type. The combination of the electrode‐based technique with layer‐by‐layer deposition enabled the formation of patterned co‐cultures within the semi‐closed tubular structure. The utility of this approach was demonstrated by patterning co‐cultures of hepatocytes or endothelial cells with fibroblasts. The controlled co‐cultures inside the elastic tubing should be of value for cell–cell interaction studies following application of chemical or mechanical stimuli and for tissue engineering‐based bioreactors. Biotechnol. Bioeng. 2007;98: 913–919. © 2007 Wiley Periodicals, Inc.
Long-term outcome of a multicentre randomized clinical trial of stapled haemorrhoidopexy versus Milligan–Morgan haemorrhoidectomy
Authors: Ganio E , Altomare D F , Milito G , Gabrielli F , Canuti S
Published: May 2007

Introduction

Stapled haemorrhoidopexy is less painful than Milligan-Morgan haemorrhoidectomy, allowing an earlier return to working activities, but its long-term efficacy is not fully established. This study reports the long-term follow-up of a randomized clinical trial comparing the two techniques in 100 patients affected by third- and fourth-degree haemorrhoids.

Methods

All patients were contacted and invited to attend the clinic to assess long-term functional outcome. The degree of continence and satisfaction were assessed by questionnaire. Anal manometry and anoscopy were performed.

Results

Eighty patients were available after a median follow-up of 87 months. No statistically significant differences were found between the two groups in terms of incontinence, stenosis, pain, bleeding, residual skin tags or recurrent prolapse. A tendency towards a higher recurrence rate was reported in patients with fourth-degree haemorrhoids, irrespective of the technique used. No significant changes in anal manometric values were found after surgery in either group.

Conclusion

Both techniques are effective in the long term.
Trends in stomach and pancreatic cancer incidence and mortality in England and Wales, 1951–2000
Authors: Fitzsimmons D , Osmond C , George S , Johnson C D
Published: May 2007

Background

The aim of this study was to describe period and cohort effects in incidence and mortality of stomach and pancreatic cancer in England and Wales.

Methods

National figures for mortality (1951–2000) and incidence (1971–2000) were analysed using log-linear Poisson regression models to obtain relative risks (RR) for period (year of incidence or death) and cohort (year of birth).

Results

Stomach cancer shows a pronounced cohort effect in mortality with a decline in RR in men from 2·20 (1876) to 0·47 (1946) and a reduction from 2·79 to 0·41 for women. Mortality to incidence ratios are now less than 0·70. Pancreatic cancer mortality (men) RR rose from 0·91 (1951–1955) to a peak 1·11 (1976–1980) and then declined to 0·90 (1996–2000). Women showed a similar pattern. Cohort RR (men) increased to a peak of 1·14 in 1916 and declined to 1·01 in 1946, and continued to fall; the peak occurred slightly later in women. Mortality to incidence ratios were near 1 in the first 20 years, declining to 0·95 in the last 10 years.

Conclusion

Stomach cancer incidence has fallen continuously from 19th century birth cohorts onwards. Incidence of pancreatic cancer has fallen in successive birth cohorts after 1920; peak period risk was 1976–1990. Age-standardized mortality and case mortality for pancreatic cancer are declining.
Nationwide study of the outcome of popliteal artery aneurysms treated surgically
Authors: Ravn H , Bergqvist D , Björck M
Published: May 2007

Background

The aim was to study the epidemiology and outcomes of popliteal artery aneurysm (PA) treated surgically.

Methods

Among 110 000 procedures registered prospectively in the Swedish Vascular Registry (Swedvasc), there were 717 primary operations for PA among 571 patients. Patient records were reviewed and data validated against other registries.

Results

The median age of the patients was 71 years; 5·8 per cent were women. Among 264 legs treated urgently, 235 had acute ischemia and 24 had rupture. Of patients with unilateral PA, 28·1 per cent had an aortic aneurysm, 8·4 per cent an iliac aneurysm and 9·4 per cent a femoral aneurysm. Extra-popliteal aneurysms were more common when the PAs were bilateral (P = 0·004). The rate of limb loss within 1 year of operation was 8·8 per cent; 12·0 per cent for symptomatic and 1·8 per cent for asymptomatic limbs (P < 0·001). Risk factors for amputation were symptomatic disease, poor run-off, urgent treatment, age over 70 years, prosthetic graft and no preoperative thrombolysis when the ischaemia was acute. Amputation rates decreased over time (P = 0·003). Crude survival was 91·4 per cent at 1 year and 70·0 per cent at 5 years.

Conclusion

Multiple aneurysm disease was common when PAs were bilateral. Preoperative thrombolysis of acute thrombosis and the use of vein grafts for bypass improved outcome.
Evaluation of various POSSUM models for predicting mortality in patients undergoing elective oesophagectomy for carcinoma
Authors: Lai F , Kwan T L , Yuen W C , Wai A , Siu Y C , Shung E
Published: May 2007

Background

The aim of the study was to validate the use of the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM), Portsmouth (P) POSSUM and upper gastrointestinal (O) POSSUM models in patients undergoing elective thoracic oesophagectomy for carcinoma.

Methods

The observed in-hospital mortality rates in 545 patients undergoing elective thoracic oesophagectomy for squamous cell carcinoma of the oesophagus in all public hospitals in Hong Kong was compared with rates predicted by POSSUM, P-POSSUM and O-POSSUM. The discriminatory power of these models was assessed using receiver–operator characteristic (ROC) curve analysis.

Results

The observed mortality rate was 5·5 per cent, whereas rates predicted by POSSUM, P-POSSUM and O-POSSUM were 15·0, 4·7 and 10·9 per cent respectively. P-POSSUM showed no lack of fit (P = 0·814), but POSSUM (P < 0·001) and O-POSSUM (P = 0·002) showed lack of fit against observed mortality. POSSUM overpredicted mortality across nearly all risk groups, whereas O-POSSUM overpredicted mortality in patients with low physiological scores and in older patients. POSSUM (area under ROC curve 0·776) and P-POSSUM (0·776) showed equally good discriminatory power but O-POSSUM (0·676) was inferior.

Conclusion

P-POSSUM provided the most accurate prediction of in-hospital mortality in this group of patients who had elective oesophagectomy.
Über Pteridine, V. Mitteil.: Die Konstitution des Ichthyopterins
Authors: Tschesche Rudolf , Korte Friedhelm
Published: May 2007

Es wurde papierchromatographisch erkannt, daß das von R. Hüttel und G. Sprengling beschriebene Ichthyopterin aus den Häuten von Cypriniden des Bodensees nicht vollkommen einheitlich ist. Die Hauptkomponente ist die 6.9‐Dioxy‐2‐amino‐pteridyl‐(8)‐essigsäure; sie wurde synthetisch bereitet und stimmt in allen Eigenschaften mit dem Naturprodukt überein, soweit ein Vergleich bei den vorliegenden geringen Mengen des letztgenannten möglich war.
Über Verbindungen mit Urotropin‐Struktur, III. Mitteil.: Darstellung des Ringsystems des 2.4.9‐Trioxa‐adamantans
Authors: Stetter Hermann , Dohr Manfred
Published: May 2007

Triallyl‐ und Trimethallyl‐carbinol wurden durch Umsetzung von Chlorameisensäureester mit Allyl‐ und Methallyl‐magnesiumchlorid dargestellt. Durch Ozonisation des Triallyl‐carbinols und reduzierende Spaltung des Triozonids in Alkohol wurde das Hexaacetal des Oxymethan‐triacetaldehyds erhalten. Die Verseifung des Acetals ergab 7‐Oxy‐2.4.9.‐trioxa‐adamantan. In ähnlicher Weise konnte durch Ozonolyse des Trimethallylcarbinols 7‐Oxy‐1.3.5‐trimethyl‐2.4.9‐trioxa‐adamantan erhalten werden.
Synthese des 3′.8‐Dimethyl‐1.2‐cyclopenteno‐phenanthrens
Authors: Woodward Robert Burns , Inhoffen Hans Herloff , Larson Harold O. , Menzel Karl‐Heinz
Published: May 2007

Die Totalsynthese des 3′.8‐Dimethyl‐1.2‐cyclopenteno‐phenanthrens wird beschrieben und seine Identität mit dem Kohlenwasserstoff C19H18 sichergestellt, der aus Sterinphenol durch Selendehydrierung gewonnen wurde.
Synthesen nichtreduzierender Disaccharide
Authors: Bredereck Hellmut , Höschele Günther , Ruck Klaus
Published: May 2007

Bei der thermischen Kondensation von Tetraacetyl‐monosen mit freiem Lactolhydroxyl i. Ggw. von sauren Kondensationsmitteln entstehen nebeneinander die Oktaacetate der drei nichtreduzierenden Disaccharide mit α.α‐, α.β‐ und β.β‐Verknüpfung. Es ist auf diese Weise möglich, Disaccharide mit α.α‐Konfiguration darzustellen, wie durch die Synthese der α.α‐Galaktobiose gezeigt wird. Es wird ferner die Synthese von β.β‐Galaktobiose sowie eine modifizierte Darstellung von Isosaccharose‐oktaacetat beschrieben.
Die Enol‐Enolat‐Gleichgewichte und die Enol‐Methyläther einiger „trans‐fixierter”︁ β‐Diketone)
Authors: Eistert Bernd , Reiss Werner
Published: May 2007

Von einigen Cyclobutan‐, Cyclopentan‐ und Cyclohexan‐1.3‐dionen werden die UV‐Spektren der undissoziierten Enol‐Formen, der Enolat‐Anionen und der Enol‐Methyläther gemessen und diskutiert. Die Enol‐Formen dieser „trans‐fixierten”︁ β‐Diketone sind, da sie nicht chelatisiert sein können, relativ stark sauer (PKs = etwa 2.8 bis 5.5). Die Dissoziationskonstanten der Enole werden aus den bei verschiedenen pH‐Werten gemessenen UV‐Spektren berechnet. Das Enol‐Enolat‐Gleichgewicht ist bei vielen trans‐fixierten Enolen im Bereich der bei UV‐Messungen benützten Konzentrationen konzentrationsabhängig.
Synthesen mit α‐Chloräthylschwefelchlorid (VII. Mitteil. über organische Schwefelchloride)
Authors: Brintzinger Herbert , Ellwanger Hans
Published: May 2007

Es wird über die Darstellung von α‐Chlor‐äthylschwefelchlorid sowie über die mannigfaltigen, mit dieser Verbindung durchführbaren Synthesen, die u.a. auch zur Bildung von Makromolekülen durch Polykondensation und Polymerisation führen, berichtet.
Notiz über die Ozonisierung von 1.2‐Diphenyl‐inden
Authors: Bailey Philip S.
Published: May 2007

Die Literaturangabe, nach der 1.2‐Diphenyl‐inden bei der Ozonisierung in anomaler Reaktion o‐Benzoyl‐benzoin liefert, hat sich als irrtümlich erwiesen; es bildet vielmehr das normale Ozonid.
Beitrag zur Kenntnis der cyclischen Acetale des Glyoxals
Authors: Faass Ursula , Hilgert Horst
Published: May 2007

Die zwei bisher fälschlich als cis‐ und trans‐Naphthodioxan bezeichneten und bei Synthesen stets als Gemisch anfallenden isomeren Glyoxal‐bisäthylenacetale konnten auf getrennten Wegen erhalten werden. Auf Grund ihrer Bildung aus 2.3‐Dichlor‐1.4‐dioxan kommt der seither als trans‐Naphthodioxan angesehenen Verbindung vom Schmp. 136° tatsächlich die Konstitution eines Naphthodioxans zu. Die Verbindung vom Schmp. 111–112°, die auch über das Äthylenmonoacetal des Glyoxals dargestellt werden konnte, ist in Wirklichkeit Bis‐2.2'‐[1.3‐dioxolan].
Über die Synthese des 10.11‐Dimethyl‐1.2‐benzazulens und des 2.7‐Dimethyl‐[indeno‐1′.2′:9.10‐phenanthrens]
Authors: Ziegenbein Willi
Published: May 2007

Durch Ringerweiterungsreaktion konnte aus 2.3‐Dimethyl‐fluoren und Diazoessigester nach Verseifung und anschließender spontaner Dehydrierung ein Dimethyl‐1.2‐benzazulen erhalten werden. Der oxydative Abbau mit Kaliumpermanganat ergab Pyromellitsäure bzw. deren Dianhydrid, so daß auf die Struktur des 10.11‐Dimethyl‐1.2‐benzazulens geschlossen werden kann.

Die Synthese des 2.7‐Dimethyl‐[indeno‐1′.2′:9.10‐phenanthrens] wird mitgeteilt.
Photoelektrische Registrierung der Raman‐Spektren farbiger Substanzen mit He‐Ne‐6328 Å‐Laser‐Erregung
Authors: Brandmüller Josef , Hacker Herbert , Schrötter Heinz W.
Published: May 2007

Die Vorteile der Erregung von Raman‐Spektren mittels He‐Ne‐6328 Å‐Laser für Flüssigkeiten und Kristallpulver mit einer Absorption bis ca. 5800 Å und die damit verbundene Erweiterung des Anwendungsbereiches der Raman‐Spektroskopie werden gezeigt. Die dabei erforderlichen geringen Substanzmengen und einfachen Probenanordnungen werden anhand der photoelektrisch registrierten Spektren demonstriert.
Monovalent Ion Dependence of Neomycin B Binding to an RNA Aptamer Characterized by Spectroscopic Methods
Authors: Stampfl Sabine , Lempradl Adelheid , Koehler Gottfried , Schroeder Renée
Published: May 2007

Understanding the interactions of small molecules like antibiotics with RNA is a prerequisite for the development of novel drugs. In this study we address structural and thermodynamic features of such interactions by using a simple model system: the binding of the highly charged antibiotic neomycin B to a short hairpin RNA molecule. Nucleotide A16, which acts as a flap over the neomycin B binding pocket, was substituted by the fluorescent adenine analogue 2‐aminopurine (2‐AP). Steady‐state and time‐resolved fluorescence measurements were complemented by UV‐melting and circular dichroism studies. The binding of neomycin B at three sites was found to have a strong inverse correlation with Na+ concentration. For the highest‐affinity site, both fluorescence and UV absorption experiments were consistent with a model assuming at least three neomycin NH3+ groups participating in addition to hydrogen bonds in electrostatic interactions with the RNA. The variation of fluorescence intensity and lifetime upon neomycin B binding indicated unstacking of 2‐AP16 from neighbouring bases as it flipped over the binding pocket. RNA conformational changes upon binding of the antibiotic were confirmed by circular dichroism. The two weaker binding sites were characterized as unspecific binding to the aptamer, while the high‐affinity binding event was shown to be highly specific even at high ionic concentration. In addition, 2‐AP was confirmed to be a noninvasive fluorescent probe; it serves as a sensitive spectroscopic tool to investigate details of the interactions between small molecules and RNA.
New approach to septal ablation: Glue (cyanoacrylate) septal ablation
Authors: Oto Ali , Aytemir Kudret , Deniz Ali
Published: May 2007

Alcohol septal ablation is an alternative way of treatment in hypertrophic obstructive cardiomyopathy patients who are refractory to medical treatment. This case report describes a new way of septal ablation with glue (cyanoacrylate) in a HOCM patient who has extensive collateral to posterior descending coronary artery which precludes alcohol ablation. © 2007 Wiley‐Liss, Inc.
Factors affecting long‐term survival following renal artery stenting
Authors: Bates Mark C. , Campbell John E. , Stone Patrick A. , Jaff Michael R. , Broce Mike , Lavigne, Philip S.
Published: May 2007

Introduction: This study defines clinical variables at the time of renal artery stenting that may be predictors of long‐term all‐cause mortality. Methods: The data are derived from the single operator, single center, renal stent retrospective study (SOCRATES) and includes a review of 748 (336 men, 412 women) consecutive symptomatic patients with de novo atherosclerotic renal artery stenosis treated over an 11‐year period. All patients had clinical indications for renal revascularization, including, but not limited to; suboptimal control of hypertension, chronic kidney disease, and cardiac disturbance syndromes. Clinical variables at the time of the index procedure were evaluated as predictors of all‐cause mortality using multivariate analysis. Mortality data were derived from hospital records and formal queries of the State Department of Health and Human Services, Health and Vital Statistics Division database. Results: In‐hospital, 30‐day and 6‐month mortality rates were 0.5, 2.0, and 6.3%, respectively. Overall patient survival at years 1, 5, and 10 was 91.2, 66.6, and 40.9%, respectively. Comorbid conditions, including chronic obstructive pulmonary disease and congestive heart failure, were independently associated with increased mortality. There were incremental changes in mortality in patients with baseline azotemia, [preprocedure serum creatinine (sCr) 1.5–2.09 mg/dL hazard ratio 1.52; sCr >2.5 mg/dL hazard ratio 3.39]. Therapy with lipid lowering agents offered a survival advantage (hazard ratio 0.69, P = 0.0.049); however, this study was not designed to evaluate a “protective effect” of lipid lowering medications. Conclusions: Patients with chronic obstructive pulmonary disease and congestive heart failure undergoing renal artery stent revascularization have a poor long‐term prognosis. Baseline azotemia is the strongest independent predictor of all cause mortality, with more than 70% of patients with marked azotemia (sCr >2.5) dead at 5 years. © 2007 Wiley‐Liss, Inc.
New distal embolic protection device the FiberNet® 3 dimensional filter: First carotid human study
Authors: Henry Michel , Polydorou Antonios , Henry Isabelle , Liasis Nikos , Polydorou Adamantia , Polydorou Victoria , Demesticha Theano , Skandalakis Panayiotis , Kotsiomitis Evaggelos , Hugel Michel , Sedgewick Jerry , Ruth George
Published: May 2007

Objective: Evaluate the performance and safety of the FiberNet® Embolic Protection System during carotid artery intervention. Background: Carotid Angioplasty and Stenting (CAS) can be proposed to treat the majority of carotid stenoses. Brain embolization takes place and routine use of Embolic Protection Devices (EPD) is warranted. Many EPDs have significant limitations, which may be addressed by a new EPD, the FiberNet® (Lumen Biomedical, Plymouth, MN). Methods: The system consists of a 3‐dimensional expandable filter made of fibers, which expand radially, mounted onto a 0.014″ wire and retrieval catheter. FiberNet can capture particles as small as 40 μm without compromising flow. Results: 35 lesions treated in 34 patients. Male 67.6%. Age: 71.4 ± 8.8 (50–85). Average stenosis 84.5% ± 7.9 (70–99). 29.4% were symptomatic. Technical success: 34/35 (97%). No stroke or death within 30 days. Neurological events: two permanent amaurosis, one amaurosis fugax. All samples visually contained significant amounts of emboli. The mean surface area of debris caught was 63.8 mm2 (37.7–107.5). Comparisons were made with other EPDs. The mean surface area of debris caught was 12.2 mm2 (2.7–34.3). No changes were noted in CT/MRI at 30‐day post procedure. Conclusion: The first human use of this new novel EPD in carotid artery stenting is encouraging. The FiberNet was easy to use and confirmed the ability to capture particles less than 100 μm. The feasibility of the FiberNet has been demonstrated. Additional patients will demonstrate the overall safety and efficacy of this new EPD device. © 2007 Wiley‐Liss, Inc.
Alcohol septal ablation after failed surgical myectomy
Authors: Joyal Dominique , Arab Dinesh , Chen‐Johnston Carol , Leya Ferdinand
Published: May 2007

We describe the case of a successful alcohol septal ablation in a patient with persistent gradient and severe symptoms postsurgical myectomy. The alcohol ablation of the thickened septum abolished the left ventricular outflow gradient and the systolic anterior motion (SAM) of the mitral valve. Although the surgical literature advocates for mitral valve replacement in patients who continue to have SAM with significant outflow obstruction postmyectomy, targeted alcohol septal ablation of the remaining septum appears to be an attractive alternative. © 2007 Wiley‐Liss, Inc.
Overview of the 2006 Food and Drug Administration Circulatory System Devices Panel meeting on drug‐eluting stent thrombosis
Authors: Pinto Slottow Tina L. , Waksman Ron
Published: May 2007

Drug‐eluting stents (DES) seemed likely to mitigate the problem of restenosis and have become the predominant stent deployed during percutaneous coronary intervention (PCI). Sustained concerns about the rate of stent thrombosis (ST), particularly very late ST (>1 year following PCI) led to a meeting of the Circulatory System Devices Advisory Panel to address “on‐label” and “off‐label” use as well as appropriate duration of dual antiplatelet therapy following DES. Over 40 presentations by members of the FDA, industry personnel, and leaders in the field of interventional cardiology helped set forth the body of data available on DES. Standardized definitions of ST created by the Academic Research Consortium were applied to existing randomized trials and registries. At the end of the 2‐day session, the consensus of the panel was that “on‐label” DES use is not associated with increased incidence of death and myocardial infarction (MI), although it is associated with increased rates of very late ST. “Off‐label” use is associated with increased risk of death or MI when compared with “on‐label” use. Insufficient data exist to determine the duration of clopidogrel that would minimize ST and bleeding risk, but the panel agreed with the current ACC/AHA/SCAI guidelines regarding dual antiplatelet therapy for at least 12 months in patients at low risk for bleeding, especially with “off‐label” use. More data from trials designed with better control arms and prespecified analyses of complex patients and lesions subsets over longer periods of follow‐up are needed. © 2007 Wiley‐Liss, Inc.
Percutaneous mitral valve annuloplasty for ischemic mitral regurgitation: First in man experience with a temporary implant
Authors: Dubreuil Olivier , Basmadjian Arsène , Ducharme Anique , Thibault Bernard , Crepeau Jacques , Lam Jules Y.T. , Bilodeau Luc
Published: May 2007

Objective: This study evaluated human feasibility and acute efficacy of a novel percutaneous transvenous mitral annuloplasty (PTMA™) device (Viacor) placed temporarily in the coronary sinus (CS): the implant allows in‐situ incremental adjustment to optimally reduce the anterior–posterior mitral annulus (MA) dimension, and improve leaflet co‐aptation and reducing mitral regurgitation (MR). Background: Surgical annuloplasty remains the standard treatment of severe ischemic MR but its application is limited by high morbidity and mortality. The effectiveness of PTMA device (Viacor) to reduce MR in the short‐term has been demonstrated in animals studies but not in humans. Methods: Symptomatic patients with ischemic MR graded 2+ to 4+ requiring surgical mitral annuloplasty were screened. Patients with any mitral leaflet or mitral apparatus abnormality were excluded. Preoperatively, under general anesthesia and transesophageal echocardiography guidance, a temporary PTMA device was placed via the right internal jugular or subclavian vein. Results: Four patients were studied. After device placement and adjustment, regurgitant volume was substantially reduced (45.5 ± 24.4 to 13.3 ± 7.3 ml) via MA anterior–posterior diameter reduction (40.75 ± 4.3 to 35.2 ± 1.6 mm) in 3 patients. In one patient, the PTMA device could not be deployed due to extreme angulated anatomy. Conclusions: PTMA in human is feasible and reduces ischemic MR (to grade 1+) by reducing MA anterior–posterior diameter. Temporary placement of the PTMA device may assist in the development of permanent implants and ensure optimal efficacy. © 2007 Wiley‐Liss, Inc.
Porphyrin, Phthalocyanine and Porphyrazine Derivatives with Multifluorenyl Substituents as Efficient Deep‐Red Emitters
Authors: Barker Carl A. , Zeng Xianshun , Bettington Sylvia , Batsanov Andrei S. , Bryce Martin R. , Beeby Andrew
Published: May 2007

The synthesis and photophysical properties are described for a series of porphyrin, phthalocyanine and pyrazinoporphyrazine derivatives which bear four or eight peripheral fluorenyl substituents as antennae. Representative examples are 5,10,15,20‐tetra(9,9‐dihexyl‐9H‐fluoren‐2‐yl)porphyrin (2), 5,10,15,20‐tetrakis[4‐(9,9‐dihexyl‐9H‐fluoren‐2‐yl)phenyl]porphyrin (3), 2,3,9,10,16,17,23,24‐octakis(9,9‐dihexyl‐9H‐fluoren‐2‐yl)‐29H,31H‐phthalocyanine (8) and 2,3,9,10,16,17,23,24‐octakis[4‐(9,9‐dihexyl‐9H‐fluoren‐2‐yl)phenyl]‐29H,31H‐tetrapyrazinoporphyrazine (9). Palladium‐mediated Suzuki–Miyaura cross‐coupling reactions have been key steps for attaching the substituents. The compounds are deep‐red emitters: λmax(em)=659 (3), 737 (8) and 684 nm (9). Their absorption and emission spectra, their fluorescence lifetimes and quantum yields are correlated with the structures of the macrocycles and the substituents. The solution fluorescence quantum yields of porphyrin derivatives substituted with fluorene (2–4) and terphenyl substituents (7) (Φf=0.21–0.23) are approximately twice that of tetraphenylporphyrin. For phthalocyanine derivative 8, Φf was very high (0.88). Specific excitation of the fluorene units of 8 produced emission from both of them (λmax=480 nm) and also from the phthalocyanine core (λmax=750 nm), indicating a competitive rate of energy transfer and radiative decay of the fluorenes. Organic light‐emitting devices (OLEDs) were made by spin‐coating techniques by using a polyspirobifluorene (PSBF) copolymer as the host blended with 3 (5 wt. %) in the configuration ITO/PEDOT:PSS/PSBF copolymer:3/Ca/Al. Deep‐red emission (λmax=663 nm; CIE coordinates x=0.70, y=0.27) was observed with an external quantum efficiency of 2.5 % (photons/electron) (at 7.5 mA cm−2), a low turn‐on voltage and high emission intensity (luminance) of 5500 cd m−2 (at 250 mA/ m2).
Using a Tripod as a Chiral Chelating Ligand: Chemical Exchange Between Equivalent Molecular Structures in Palladium Catalysis with 1,1,1‐Tris(oxazolinyl)ethane (“Trisox”)
Authors: Foltz Carole , Enders Markus , Bellemin‐Laponnaz Stéphane , Wadepohl Hubert , Gade Lutz H.
Published: May 2007

Threefold symmetrical chiral podands may simplify the stereochemistry of key catalytic intermediates for cases in which they only act as bidentate ligands. This applies to systems in which chemical exchange between the different κ2‐coordinated forms takes place and in which the non‐coordinated sidearm may play a direct or indirect role at some earlier or later stage in the catalytic cycle. Palladium(II)‐catalysed allylic substitutions provide appropriate test reactions along these lines. A series of neutral dichloropalladium(II) complexes, [PdCl2(iPr‐trisox)] (1 a), [PdCl2(Ph‐trisox)] (1 b), [PdCl2(Bn‐trisox)] (1 c) and [PdCl2(Ind‐trisox)] (1 d) (trisox=1,1,1‐tris(oxazolinyl)ethane) were synthesised by reaction of the respective trisox derivative with [PdCl2(PhCN)2] and characterised inter alia by 15N NMR spectroscopy. Direct detection of the heteronuclei without isotope enrichment and with “normal” sample concentrations was achieved with the aid of a cryogenically cooled NMR probe on a 600 MHz NMR spectrometer. Whereas the 15N nuclei of the coordinated oxazoline rings resonate at δ=160–167 ppm and appear as two singlets due to their diastereotopicity, the signal assigned to the dangling oxazoline “arm” is observed at δ=238–240 ppm. Variable‐temperature NMR studies along with a systematic series of magnetisation transfer experiments established exchange between ligating and non‐ligating oxazoline rings. Reaction of [Pd(allyl)(cod)]BF4 (cod=cyclooctadiene) with Ph‐trisox in CH2Cl2 gave the corresponding allyl complex 2, for which fast exchange between the three oxazoline heterocycles as well as between the exo and endo diastereomers was observed along with a very slow η3‐η1‐η3 process of the allyl fragment (magnetisation transfer). Palladium(0) complexes were prepared by reaction of trisox derivatives or sidearm‐functionalised BOX (BOX=bis(oxazolinyl)dimethylmethane) ligands with [Pd(nbd)(alkene)] (nbd=norbornadiene, alkene=maleic anhydride or tetracyanoethylene). X‐ray diffraction studies of the iPr‐trisox and Ph‐trisox complexes (3 a and 3 b) established Y‐shaped trigonal planar coordination geometries with the trisox ligand coordinated in a bidentate fashion, whilst the π‐coordinated maleic anhydride ligand adopts one of the two possible diastereotopic orientations. As the catalytic test reaction, the allylic alkylation of 1,3‐diphenylprop‐2‐enyl acetate substrate with dimethyl malonate as nucleophile (in the presence of N,O‐bis(trimethylsilyl)acetamide) was investigated for the trisox derivatives, their BOX analogues, and a series of less symmetric “sidearm” functionalised bisoxazolines. The trisoxazoline‐based catalysts generally induce a better enantioselectivity compared to their bisoxazoline analogues and display significant reduction of the induction period as well as rate enhancement.
The Total Synthesis and Biological Properties of the Cytotoxic Macrolide FD‐891 and Its Non‐Natural (Z)‐C12 Isomer
Authors: García‐Fortanet Jorge , Murga Juan , Carda Miguel , Marco J. Alberto , Matesanz Ruth , Díaz J. Fernando , Barasoain Isabel
Published: May 2007

A total, stereoselective synthesis of the naturally occurring, cytotoxic macrolide FD‐891 and of its non‐natural (Z)‐C12 isomer is described. Three fragments of the main carbon chain were stereoselectively prepared by using asymmetric aldol and allylation reactions as the key steps. The molecule was then assembled by using two Julia–Kocienski olefinations to connect the three fragments and a Yamaguchi reaction to close the macrolactone ring. Some specific biological properties (cytotoxicity, binding to tubulin) have been determined for both macrolides. The E configuration of the C12–C13 olefinic bond seems to be an important feature in determining the cytotoxicity but the precise biological mechanism of the latter still remains to be cleared.
Racemization of Secondary Alcohols Catalyzed by Cyclopentadienylruthenium Complexes: Evidence for an Alkoxide Pathway by Fast β‐Hydride Elimination–Readdition
Authors: Martín‐Matute Belén , Åberg Jenny B. , Edin Michaela , Bäckvall Jan‐E.
Published: May 2007

The racemization of sec‐alcohols catalyzed by pentaphenylcyclopentadienyl–ruthenium complex 3 a has been investigated. The mechanism involves ruthenium–alkoxide intermediates: reaction of tert‐butoxide ruthenium complex 4 with a series of sec‐alcohols with different electronic properties gave ruthenium complexes bearing a secondary alkoxide as a ligand. The characterization of these alkoxide complexes by NMR spectroscopy together with a study of the reaction using in situ IR spectroscopy is consistent with a mechanism in which the alkoxide substitution step and the β‐hydride elimination step occur without CO dissociation. The alkoxide substitution reaction is proposed to begin with hydrogen bonding of the incoming alcohol to the active ruthenium–alkoxide intermediate. Subsequent alkoxide exchange can occur via two pathways: i) an associative pathway involving a η3‐CpRu intermediate; or ii) a dissociative pathway within the solvent cage. Racemization at room temperature of a 1:1 mixture of (S)‐1‐phenylethanol and (S)‐1‐phenyl‐[D4]‐ethanol gave only rac‐1‐phenylethanol, and rac‐1‐phenyl‐[D4]‐ethanol, providing strong support for a mechanism in which the substrate stays coordinated to the metal center throughout the racemization, and does not leave the coordination sphere. Furthermore, racemization of a sec‐alcohol bearing a ketone moiety within the same molecule does not result in any reduction of the original ketone, which rules out a mechanism where the intermediate ketone is trapped within the solvent cage. These results are consistent with a mechanism where η3‐Ph5C5–ruthenium intermediates are involved. Competitive racemization on nondeuterated and α‐deuterated α‐phenylethanols was used to determine the kinetic isotope effect kH/kD for the ruthenium‐catalyzed racemization. The kinetic isotope effect kH/kD for p‐ X‐C6H4CH(OH)CH3 was 1.08, 1.27 and 1.45 for X=OMe, H, and CF3, respectively.
Efficient Tandem Process for the Catalytic Deprotection of N‐Allyl Amides and Lactams in Aqueous Media: A Novel Application of the Bis(allyl)–Ruthenium(IV) Catalysts [Ru(η3:η2:η3‐C12H18)Cl2] and [{Ru(η3:η3‐C10H16)(μ‐Cl)Cl}2]
Authors: Cadierno Victorio , Gimeno José , Nebra Noel
Published: May 2007

An operationally simple and highly efficient methodology for the removal of the allyl protecting group in amides and lactams has been developed by using the commercially available bis(allyl)–ruthenium(IV) catalysts [Ru(η3:η2:η3‐C12H18)Cl2] (C12H18=dodeca‐2,6,10‐triene‐1,12‐diyl) and [{Ru(η3:η3‐C10H16)(μ‐Cl)Cl}2] (C10H16=2,7‐dimethylocta‐2,6‐diene‐1,8‐diyl). The tandem process, which takes place in aqueous media and proceeds in a one‐pot manner, involves the initial isomerization of the CC bond of the allyl unit and subsequent oxidative cleavage of the resulting enamide.
Ionic Liquids for Soft Functional Materials with Carbon Nanotubes
Authors: Fukushima Takanori , Aida Takuzo
Published: May 2007

A serendipitous finding that ionic liquids gel with carbon nanotubes has opened a new possibility of ionic liquids as modifiers for carbon nanotubes. Upon being ground into ionic liquids, carbon nanotube bundles are untangled, and the resultant fine bundles form a network structure. This is due to the possible specific interaction between the imidazolium ion component and the π‐electronic nanotube surface. The resultant gelatinous materials, consisting of highly electroconductive nanowires and fluid electrolytes, can be utilized for a wide variety of electrochemical applications, such as sensors, capacitors, and actuators. Ionic liquids allow for noncovalent and covalent modifications of carbon nanotubes and fabrication of polymer composites with enhanced physical properties. The processing of carbon nanotubes with ionic liquids is not accompanied by the disruption of the π‐conjugated nanotube structure and does not require solvents; therefore it can readily be scaled up. This article focuses on new aspects of ionic liquids for designer soft materials based on carbon nanotubes.
Herstellung von Wasserstoff aus nachwachsenden Rohstoffen mit molekular definierten Katalysatoren
Authors: Loges B. , Junge H. , Spilker B. , Fischer C. , Beller M.
Published: May 2007

Die Dehydrierung von Alkoholen ist eine viel versprechende Möglichkeit zur Erzeugung von Wasserstoff aus erneuerbaren Rohstoffen und deren Folgeprodukten. Molekular definierte Katalysatoren können der Schlüssel zu effizienten und nachhaltigen Verfahren sein, denn sie ermöglichen die Wasserstoffbildung unter vergleichsweise milden Bedingungen. So kann in Gegenwart von metallorganischen Komplexen des Rutheniums unterhalb von 100 °C aus 2‐Propanol, 1‐Phenylethanol und Ethanol Wasserstoff entwickelt werden (Katalysatoraktivitäten bis zu 500 mol H2/mol Katalysator und h). Im hergestellten Wasserstoff ist kein CO nachzuweisen, was ihn für die Anwendung in Brennstoffzellen prädestiniert.
Moderne Methoden der In‐situ‐Festkörper‐NMR‐Spektroskopie in der heterogenen Katalyse
Authors: Hunger M.
Published: May 2007

Die in dieser Arbeit beschriebenen Techniken der In‐situ‐Festkörper‐NMR‐Spektroskopie ermöglichen praxisnahe Untersuchungen zur Natur der Oberflächenzentren von Feststoffkatalysatoren an adsorbierten Reaktanden und Zwischenprodukten und zum Mechanismen heterogen katalysierter Reaktionen. Die dargestellten Anwendungsbeispiele sind Untersuchungen zur Beckmann‐Umlagerung von Cyclohexanonoxim an unterschiedlich sauren Zeolith‐Katalysatoren unter Satzbedingungen, zum Hydratisierungs‐ und Dehydratisierungsverhalten mikroporöser Silicoalumophosphate und zur Koksbildung während der Umsetzung von Methanol an Zeolith‐Katalysatoren unter Strömungsbedingungen. Im letztgenannten Fall werden die Vorteile der Kombination komplementärer spektroskopischer und analytischer Methoden in einer Messanordnung demonstriert.
Verbesserung der Selektivität fester Katalysatoren durch die Beschichtung mit ionischen Flüssigkeiten – Untersuchungen am Beispiel der Hydrierung von Cyclooctadien
Authors: Kernchen U. , Etzold B. , Korth W. , Jess A.
Published: May 2007

Ein neues Konzept zur Verbesserung der Selektivität fester Katalysatoren durch die Beschichtung der inneren Oberfläche mit ionischen Flüssigkeiten (ILs) wird vorgestellt. Als erstes Modellsystem wurde die sequentielle Hydrierung von Cyclooctadien zu Cycloocten und Cyclooctan an einem kommerziellen Ni‐Katalysator getestet, der mit der ionischen Flüssigkeit [BMIM][n‐C8H17OSO3] beschichtet wurde. Im Vergleich zum unbeschichteten Katalysator steigt die Maximalausbeute des Zwischenproduktes Cycloocten durch die Beschichtung mit der ionischen Flüssigkeit deutlich von 40 auf 70 % an. Dieser Effekt, der bereits bei einem Porenfüllgrad von 10 % erreicht wird, kann nicht durch Porendiffusionseffekte erklärt werden, wie Experimente mit unterschiedlichen Korngrößen und entsprechende Berechnungen zeigen. Die IL‐Schicht ist stabil, und ein Auswaschen in die organische Phase konnte nicht festgestellt werden.
Characterization of the Oxidation States of Supported Gold Species by IR Spectroscopy of Adsorbed CO
Authors: Mihaylov M. , Knözinger H. , Hadjiivanov K. , Gates B. C.
Published: May 2007

The use of IR spectroscopy of adsorbed CO for determination of gold speciation on supported gold catalysts is reviewed. Different ionic and metallic sites (Au3+, Au+, Au0, and Au–) can be differentiated on the basis of the frequency and stability of their surface carbonyl species formed after CO adsorption. In addition, the study of CO adsorption and reaction with other gases can provide unique information on the mechanisms of catalytic reactions with participation of CO. Finally, results from complementary techniques such as X‐ray absorption spectroscopy, also useful for determination of gold oxidation state, are briefly considered.
Comparison of Large Pore Zeolites for n‐Octane Hydroisomerization: Activity, Selectivity and Kinetic Features
Authors: Chica A. , Corma A.
Published: May 2007

The hydroisomerization of n‐octane has been catalyzed by different zeolitic structures with large pore size (12 MR). It has been seen that channel topology, chemical composition, crystal size, and adsorption properties are of paramount importance for improving the isomerization activity and selectivity. Nanocrystalline beta zeolite (30 nm) with large pore size (0.66 × 0.67 and 0.56 × 0.56 nm), and high aluminum content (Si/Al = 16), was the best catalyst to produce multibranched isomers. Cracking reactions also occur together with isomerization and the product distribution will depend on the rate constant and relative activation energies of isomerization, desorption, and cracking. Furthermore, a complete kinetic study of n‐octane isomerization has been carried out with beta zeolite, and kinetic rate constants, heats of adsorption, and activation energies have been determined for each individual isomerization step. The rate of isomerization of n‐octane to monobranched products was found to be faster than the rate of cracking of dibranched products and the rate of isomerization of mono‐ to dibranched products. It should be possible to obtain high yields of dibranched alkanes by distillation and recycling units, or by using membrane reactors.
Tetraethylorthosilicat–modifizierte Zeolithe als Katalysatoren für die Dehydroalkylierung von Toluol mit Ethan
Authors: Traa Y. , Singer D.
Published: May 2007

Die post‐synthetische Modifizierung mit Tetraethylorthosilicat (TEOS) ist eine vielseitige Methode zur Beeinflussung der Aktivität und Selektivität von Zeolithkatalysatoren. In dieser Arbeit werden die so modifizierten Zeolithe als Katalysatoren für die Dehydroalkylierung von Toluol mit Ethan zu den isomeren Ethyltoluolen verwendet. Ethyltoluole sind Vorläufer für Polymere mit interessanten Eigenschaften.
Zur Synthese von MFI‐ Materialien auf Edelstählen
Authors: Brehm A. , Zanter K.‐D.
Published: May 2007

MFI‐Materialien (ZSM‐5, Silicat‐1) bilden sich während der Synthese auf der Oberfläche von Trägern. Sie werden über die Kondensation von Hydroxidgruppen an deren Oberfläche gebunden. Edelstähle unterscheiden sich in ihrer Art und den Anteilen der Legierungsbestandteile. Diese Unterschiede beeinflussen die Anhaftung von MFI‐Materialien und die Bildung eines krustenartigen Films sehr stark. Es kann gezeigt werden, dass spezifische Legierungsbestandteile wie Fe, Ni, Cr, Mo ebenso wie das Si/Al‐Verhältnis und die zur Vorbehandlung der Legierungen eingesetzten Verfahren das Zeolithwachstum beeinflussen.
Thermische Regenerierung von Zeolithpulver Typ X aus der VOC‐Luftreinigung
Authors: Noack M. , Dittmar A. , Stöhr M. , Georgi G. , Adam C. , Brenneis R. , Kley G. , Lehmann A. , Handte J. , Meichle K. , Schwake M.
Published: May 2007

Für die Entfernung von VOC (volatile organic compounds) aus der Luft von Fertigungsstätten werden vielfach mikroporöse Adsorbentien eingesetzt. Die gereinigte Luft wird rezyklisiert. Für die mit VOC beladenen Adsorbentien wird ein Regenerierungsweg für den mehrfachen Gebrauch gesucht. Bei der Regenerierung sollen die VOC möglichst vollständig desorbiert werden und mit einer geringen Gasmenge in einer katalytischen Verbrennung zu CO2 und H2O umgewandelt werden. Die Wirtschaftlichkeit der Luftreinigung wird wesentlich bestimmt durch die Sorptionskapazität des Adsorbens, die erforderliche Energie für die thermische Regenerierung und die Menge des Spülgases bei der Regenerierung. In dieser Arbeit wird der Einsatz von Typ X‐Zeolithpulver in der Luftreinigung einer Lackiererei beschrieben und dessen Regenerierung im Labor mittels DTA/TG und Isothermenmessung der Schlüsselkomponenten untersucht. Ferner wurde die Regenerierung des beladenen Zeoliths in einem Labor‐Drehrohrofen unter Variation der Betriebsparameter untersucht und anschließend mit ausgewählten Parametern in einem kleintechnischen Drehrohrofen durchgeführt. Die Verfahrensvarianten werden diskutiert.
Neues umweltfreundliches Herstellungsverfahren für primäre Amine durch Hydroaminomethylierung von Olefinen in überkritischem Ammoniak
Authors: Martin A. , Kant M. , Jackstell R. , Klein H. , Beller M.
Published: May 2007

Zur Hydroaminomethylierung von Olefinen in nahe‐ bzw. überkritischem Ammoniak wird ein neues Verfahren entwickelt. Dazu wird ein Messstand zur Ermittlung thermodynamischer Daten von Reaktand‐ und möglichen Produktgemischen eingerichtet und eine genaue Untersuchung der kritischen Reaktionsparameter durchgeführt. Diese thermodynamischen Daten (kritische Punkte (p, T)) werden mittels Opaleszenzmessungen in einer Sichtzelle erhalten. Bimetallische Rh/Ir‐Katalysatoren erreichen in einem Katalysatorscreening bei der Hydroaminomethylierung von 1‐Octen als Modellolefin Ausbeuten an primären Aminen zwischen 45 und 60 % bei durchschnittlichen n/i‐Verhältnissen von 56:44. Die Arbeitsdrücke bewegen sich bei 140 °C im Bereich von 190 – 240 bar. Daneben werden 15 – 22 % sekundäre Amine (R2NH), 4 – 7 % Octan, 3 – 4 % isomere Octene und geringe Mengen an sekundären und tertiären Kondensationsprodukten gefunden.
Zentrenstruktur und Vergiftungswirkungen bei der selektiven katalytischen Reduktion von NO mit Ammoniak an Fe‐ZSM‐5‐Katalysatoren
Authors: De Toni A. , Schwidder M. , Grünert W. , Brückner A.
Published: May 2007

Drei Fe‐ZSM‐5‐Katalysatoren unterschiedlicher Präparation und Speziesstruktur werden hinsichtlich des Einflusses von Feuchtigkeit und SO2 auf ihr katalytisches Verhalten bei der selektiven katalytischen Reduktion (SCR) von NO mit NH3 untersucht. Es wird gefunden, dass Wasser für diese Reaktion ein schwaches Gift ist, das offenbar auf verschiedene Zentren unterschiedlich wirkt: Im trockenen Medium beobachtete Aktivitätsunterschiede werden komplett eingeebnet. SO2 hat im trockenen Medium in keinem Fall Einfluss auf die SCR‐Reaktion, drängt jedoch die Totaloxidation des Ammoniaks zurück, sodass deutlich höhere Spitzenumsätze des NO erzielt werden. Bei gleichzeitiger Anwesenheit von H2O und SO2 erreichen alle Katalysatoren das gleiche Aktivitätsniveau, das nur wenig unter der höchsten im trockenen Medium beobachteten Aktivität liegt. Bei Langzeitbelastung mit H2O und SO2 tritt jedoch erhebliche Desaktivierung ein. Die danach verbleibende Restaktivität wird überwiegend von isolierten Fe‐Zentren getragen.
Kompaktreformer für die dezentrale Wasserstoffbereitstellung aus Erdgas
Authors: Gritsch A. , Kolios G. , Nieken U. , Eigenberger G.
Published: May 2007

Die Dampfreformierung von Erdgas bietet zurzeit die wirtschaftlich sinnvollste Option für die stationäre dezentrale Wasserstofferzeugung zur Nutzung in Brennstoffzellen. Basierend auf einem Überblick über den Stand der Technik und einer Analyse der Anforderungen an eine kompakte, energetisch effiziente Reformierung wird ein Kleinreformer mit einer Leistung von 5 m3N/h Wasserstoff (entsprechend 15 kW Heizwert) vorgestellt. Er zeichnet sich durch eine thermisch effiziente Integration von katalytischer Reformierung und Verbrennung aus und besitzt eine volumenspezifische Reformerleistung von 7 m3N Wasserstoff/Liter/h, einen thermischen Wirkungsgrad von 90 % über einen breiten Lastbereich und ein hervorragendes Lastfolgeverhalten.
Perowskit‐Hohlfasermembranen für die katalytische Partialoxidation von Methan zu Synthesegas
Authors: Caro J. , Caspary K. J. , Hamel C. , Hoting B. , Kölsch P. , Langanke B. , Nassauer K. , Noack M. , Schiestel T. , Schroeder M. , Byun Y. C. , Seidel‐Morgenstern A. , Tsotsas E. , Wang H. , Werth S.
Published: May 2007

Die Kombination einer Membran mit einer katalytischen Reaktion in einem Membranreaktor ist eines der Konzepte multifunktionaler Reaktoren zur Prozessintensivierung. Eine industriell besonders interessante Anwendung ist dabei die Darstellung von Synthesegas durch partielle Oxidation von Methan zu Kohlenmonoxid und Wasserstoff, wobei der Sauerstoff durch eine gemischtleitende Perowskit‐Membran aus Luft zudosiert wird. Es ist gelungen, entsprechende Perowskit‐Membranen als Hohlfasern mit einer volumenbezogenen Membranfläche von bis zu 500 m2/m3 durch einen ökonomischen Spinnprozess zu entwickeln. Unter Laborbedingungen konnten langzeitstabil Synthesegas (CO, H2) mit einer CO‐Selektivität von 95 % bei 95 % CH4‐Umsatz erzeugt und die Ergebnisse durch eine detaillierte mathematische Modellierung beschrieben werden.
Novell Ternary and Polynary Vanadium(IV) Phosphates as Catalysts for Selective Oxidations of Light Hydrocarbons
Authors: Glaum R. , Benser E. , Hibst H.
Published: May 2007

Ternary and polynary phosphates of transition metals offer various chemical and structural properties that make them interesting as catalyst materials for the selective oxidation of light alkanes. Redox potentials, oxygen decomposition pressures, acid‐base behavior, and structural chemistry of anhydrous transition metal phosphates may be varied over a wide range. Thus, for selective oxidation reactions of various light hydrocarbons Cn (1 ≤ n ≤ 4) suitable ternary or polynary vanadium phosphates were found. In this contribution, our recent results concerning synthesis, crystallographic characterization and catalytic properties of novell ternary and polynary vanadium(IV) phosphates [(MIIIVIV3O3(PO4)3 and MIII2(VIVO) (P2O7)2 (MIII: V, Cr, Fe), MIIVIV2O2(PO4)2 (MII: Co, Ni, Cu), and FeIIFeIII(VIVO)(PO4)(P2O7)] in the selective oxidation of n‐butane and 1‐butene to maleic acid anhydride are summarized.
Reaktivabscheidung von Platin aus überkritischem Kohlendioxid zur Herstellung von Monolith‐Katalysatoren für die Autoabgasreinigung
Authors: Schüle A. , Aschenbrenner H. , Gieshoff J. , Dapurkar S. , Schmidt M. , Upper G. , Türk M. , Kolios G. , Eigenberger G. , Gläser R.
Published: May 2007

Edelmetallhaltige Katalysatoren werden in zahlreichen Verfahren und Prozessen der petrochemischen und chemischen Industrie sowie im Umweltschutz verwendet. Eine wichtige Anwendung ist die Reinigung von Abgasen aus Dieselmotoren von Kraftfahrzeugen mit Hilfe von Oxidationskatalysatoren. Vorgestellt wird die Reaktivabscheidung von Platin aus überkritischem Kohlendioxid auf mit Washcoat beschichteten Monolithen zur Herstellung von Katalysatoren für die Reinigung von Automobilabgasen.