The use of McMurry coupling for the synthesis of indolophanes and cis-stilbenophanes

Treatment of 2 equiv of indole-3-aldehyde with o, m, p-xylyl, 2,5-dimethoxy-p-xylyl dibromides and 4,4′-bis(bromomethyl)-1,1′-biphenyl gave the bisalkylated products, which underwent McMurry coupling with low valent titanium to give indolophanes. Various cis-stilbenophanes with m-terphenyl building blocks were also synthesized by application of the McMurry coupling technique.     

Phase separation of quaternary solubilized solutions or micro emulsion of hydrocarbons containing sodium oleate + phenol + benzene + water by freezing point measurements

Summary The depressions in freezing point measurements in quaternary solubilized solutions or micro-emulsion in sodium oleate + phenol + benzene + water are measured. Maxima and minima were observed, Gibbs' phase rule was applicable, eutectic points were detected, congruent melting points were obtained, loose combination of molecules or clusters, were formed, phases of the system transferred and finally unstable emulsion separated out. This is contrary to the views ofMcBain who called these solutions as thermodynamically stable. The results were compared with the conductivity, stability and heat of solubilization-concentration measurements.

---

Zusammenfassung Es wird die Gefrierpunktserniedrigung von quaternären solubilisierten Lösungen im System Natriumoleat-Phenol-Benzol-Wasser gemessen. Die verschiedenen Befunde (Maxima und Minima des Gefrierpunktes in Abhängigkeit von der Zusammensetzung, Anwendbarkeit der Gibbs'schen Phasenregel, Auftreten von Eutektika, kongruente Schmelzpunkte etc.) dienen zum Beweis, daß diese Lösungen thermodynamisch instabil sind.

---

---

With 5 figures and 1 table     

Chemical Composition of Essential Oil from Pilea microphylla and its Antimicrobial Activity

Chemistry of Natural Compounds -     

Analytical study of wave diffraction by an irregular surface located on a flexible base in an ice-covered fluid

Meccanica - The reflection and transmission of surface waves propagating over an irregular surface located on a flexible base in an ice-covered fluid are analyzed within the context of linearized...     

Synthesis of novel indole based cyclophanes and cylindrical cyclophanes by tandem alkylation methodology using NaH

Treatment of 1 equiv of 1,3-bis(bromomethyl)benzene and 2,6-bis(bromomethyl)pyridine with 1 equiv of indole in the presence of NaH in THF afforded the symmetrical cyclophanes 1 and 2. Using similar methodology, cylindrical cyclophanes 3 and 4 were obtained from 2 equiv of 1,3,5-trimethyl-2,4,6-tris(bromomethyl)benzene and 1,3,5-tris(bromomethyl)benzene with 3 equiv of indole.     

Optical Emission Spectroscopy of Carbon Clusters Produced in a Hollow Cathode Sputter Source

A hollow cathode sputter source is developed to trace the production of carbon clusters and study the influence of discharge current and argon gas pressure on cluster production using an optical emission spectroscopic technique. Optical emission spectra from the hollow cathode source reveal the production of the C₂ Swan band. The sputter source is optimized for the maximum carbon cluster yield. The vibrational temperature analysis of the C₂ cluster is carried out using the Boltzmann plot method. The dependence of vibrational temperature on argon gas pressure is discussed and the dominant method for C-C association in the glow discharge is suggested.     

Volatile constituents of Origanum vulgare L., 'thymol' chemotype: variability in North India during plant ontogeny

Essential oils derived from six different phenophases, namely early vegetative stage, late vegetative stage, early flowering stage, full flowering stage (FFS), late flowering stage and seed shattering stage of Origanum vulgare L. grown in Kumaon region of Uttarakhand, India were investigated by GC and GC-MS. A total of 38 constituents, representing 97.4-99.7% of the total oil composition, were identified. Major components of oils were thymol (40.9-63.4%), p-cymene, (5.1-25.9%), γ-terpinene (1.4-20.1%), bicyclogermacrene (0.2-6.1%), terpinen-4-ol (3.5-5.9%), α-pinene (1.6-3.1%), 1-octen-3-ol (1.4-2.7%), α-terpinene (1.0-2.2%), carvacrol (<0.1-2.1%), β-caryophyllene (0.5-2.0%) and β-myrcene (1.2-1.9%). Thymol, terpinen-4-ol, 3-octanol, α-pinene, β-pinene, 1,8-cineole, α-cubebene and (E)-β-ocimene were observed to be higher during FFS. The study showed that plant stage had a significant effect on the essential oil content and composition of O. vulgare grown in the hilly tracks of Northern India.     

An approximation algorithm for a symmetric Generalized Multiple Depot, Multiple Travelling Salesman Problem

In this paper, we present an algorithm with an approximation factor of 2 for a Generalized, Multiple Depot, Multiple Travelling Salesman Problem (GMTSP) when the costs are symmetric and satisfy the triangle inequality. The algorithm requires finding a degree constrained minimum spanning tree which we compute using a Lagrangian relaxation.     

A simple spectrophotometric method for the determination of zirconium in U–Zr alloy samples in presence of fluoride ions

Journal of Radioanalytical and Nuclear Chemistry - A spectrophotometric method, circumventing interference from F− ions, during estimation of Zr in U-Zr alloy fuel, has been developed....     

The effect of size on the performance of a fluidized bed cooling tower

Application of the principles of the fluidization is made for cooling towers. The performance on a smaller size Fluidized Bed Cooling Tower (FBCT) is found to be encouraging. Hence a larger size FBCT is designed and the performance is found to be equally good. The pressure drop encountered in FBCT is comparable to that of conventional cooling towers. The packing height in FBCT reduces considerably because of fluidization. A table is provided to show that the throughput of the FBCT is greater than that of conventional cooling towers.

---

Der Einfluß der Größe auf die Leistung eines Wirbelschicht-Kühlturms

Zusammenfassung Das Prinzip der Fluidisierung wird für Kühltürme eingesetzt. Die Leistung eines Wirbelschicht-Kühlturms mit geringer Größe ist als ermutigend angesehen worden. Deshalb wurde ein größerer Wirbelschicht-Kühlturm entwickelt, dessen Leistung ebenso gut eingestuft wurde. Der Druckverlust, der in einem Wirbelschicht-Kühlturm auftritt, ist mit dem Druckverlust in einem konventionellen Kühlturm vergleichbar. Die Packungshöhe in einem Wirbelschicht-Kühlturm verringert sich aufgrund der Fluidisierung wesentlich. In einer Tabelle wird gezeigt, daß die Durchflußleistung eines Wirbelschicht-Kühlturms erheblich größer ist, als bei konventionellen Kühltürmen.

---

Nomenclature L water flow rate, kg per hour/m² - K overall enthalpy transfer coefficient, kg per hour/m² - V active tower volume, m³/m² plan area - T _i cold water temp. deg. C - i _i enthalpy of the air at the interface, Kcal/kg - G airflow rate, kg per hour/m² - a area of water interface, m²/m³ - H _st static height of packing - T ₂ hot water temp. deg. C - i _g enthalpy of air, Kcal/kg