Regioselective chlorination of phenols in the presence of tetrahydrothiopyran derivatives

Four six-membered cyclic sulfides, namely tetrahydrothiopyran, 3-methyltetrahydrothiopyran, 4-methyltetrahydrothiopyran and 4,4-dimethyltetrahyrdrothiopyran have been used as moderators in chlorination reactions of various phenols with sulfuryl chloride in the presence of aluminum or ferric chloride. On chlorination of phenol, ortho-cresol and meta-cresol the para/ortho chlorination ratios and yields of the para-chloro isomers are higher than when no cyclic sulfide is used for all of the cyclic sulfides, but chlorination of meta-xylenol is less consistent, with some cyclic sulfides producing higher p/o ratios and others producing lower ratios than reactions having no sulfide present

The selective chlorination of phenols using novel thiapolymers as catalysts.

Extensive work on enhancing the regioselectivity of electrophilic aromatic substitution reactions has been conducted at the Centre for Clean Chemistry, University of Wales Swansea. As a continuation of that work, this project involves the development of regioselective methods for the chlorination of phenols. Previous results conducted at the Centre for Clean Chemistry have shown that polythiaalkanes behave as highly selective catalysts for the chlorination of phenols with sulfuryl chloride. The work reported in this thesis involves the syntheses of numerous novel thiapolymers, containing branched chains, cyclic aliphatic rings and aromatic rings. These novel polymeric materials were tested as catalysts for the chlorination of phenol, o-cresol, m-cresol and m-xylenol. The first chapter gives an extensive introduction to aspects of the selective chlorination of phenols and a brief introduction to green chemistry and polymer synthesis. The second chapter reports the development of synthetic routes to some novel branched thiaalkanes from secondary dibromides. The synthesised novel branched thiapolymers were shown to be, above all, excellent selective catalysts for the chlorination of m-xylenol. The third chapter reports the synthesis of branched polymers and cyclic tetrahydrothiopyrans from methyl substituted 1,5-dibromopentanes. The branched polymeric materials synthesised were shown to behave as mediocre catalysts for the chlorination of phenols. However, the cyclic sulfides synthesised were shown to be excellent selective catalyst for the chlorination of o-cresol and also good selective catalysts for the chlorination of phenol and w-cresol. The fourth chapter reports the syntheses of thiapolymers containing cyclic aliphatic and aromatic rings. The novel cyclic aliphatic containing thiapolymers proved to be very effective selective catalysts for the chlorination of phenols with excellent results for the chlorination of o-cresol, and good results for the chlorination of w-cresol and w-xylenol obtained. Some of the novel aromatic containing polymers were also shown to be selective catalysts for the chlorination of o-cresol

CN in prestellar cores

Determining the structure of and the velocity field in prestellar cores is essential to understanding protostellar evolution.} {We have observed the dense prestellar cores L 1544 and L 183 in the $N = 1 \to 0$ rotational transition of CN and \thcn in order to test whether CN is depleted in the high--density nuclei of these cores.} {We have used the IRAM 30 m telescope to observe along the major and minor axes of these cores. We compare these observations with the 1 mm dust emission, which serves as a proxy for the hydrogen column density.}{We find that while CN\jone is optically thick, the distribution of \thcn\jone intensity follows the dust emission well, implying that the CN abundance does not vary greatly with density. We derive an abundance ratio of \rm [CN]/[\hh]=\dix{-9} in L 183 and 1-3\tdix{-9} in L 1544, which, in the case of L 183, is similar to previous estimates obtained by sampling lower--density regions of the core.}{We conclude that CN is not depleted towards the high--density peaks of these cores and thus behaves like the N-containing molecules \nnhp and \nhhh. CN is, to our knowledge, the first C--containing molecule to exhibit this characteristic.Comment: Accepted for publication in A&A Letter

Legislative Update

The Legislative Update exists to inform the reader of various state and federal laws passed during the 2021-2022 legislative sessions. More specifically, the statutes discussed below relate to alternative dispute resolution (“ADR”) in its many forms. This is an annual update compiled and written by the Journal of Dispute Resolution’s Associate Members and edited by the Associate Editor-in-Chief. This year represented a wide mix of laws passed—some related to health and safety in a post-pandemic world; others posed solutions to problems relevant before the COVID-19 pandemic. Usually, the Legislative Update is limited exclusively to state legislation. We decided to include federal given the substantial impact the bills would have on arbitration and dispute resolution more broadly

Building a Japanese Manga Collection for Non-Traditional Patrons in an Academic Library

This chapter describes how the Penn Libraries began collecting Japanese- and Korean-language comics, focusing largely on manga from Japan aimed at engaging language students and instructors with Japanese library materials. These patrons are a non-traditional demographic typically not targeted by Japanese-language collecting in academic libraries. Penn’s initial approach to this collection has likewise been non-traditional, as we looked to fan and commercial portals for popular audiences to assess the pulse of contemporary publishing in Japan, rather than relying solely on library-facing resources such as WorldCat or publisher advertisements. We advocate for a holistic approach to collecting manga that embraces: dialogue with previously underserved patrons; surveys of varied online sources like marketplaces, fan websites, and social media; and active awareness of current, socially relevant topics in Japan. The methods we describe to identify, catalog, and provide bibliographic access to Japanese comic material in a library setting can be applied even in libraries that do not have staff with expertise in the language. We encourage other libraries to explore partnerships with institutions like the Penn Libraries in their communities or via interlibrary lending, who have the staff expertise and resources to develop more extensive Japanese-language manga collections. In turn, institutions such as ours have an opportunity to serve as leaders in collecting and making their collections available to the broader community

Leveraging Local Networks and International Partnerships in Japanese Collection Development

This chapter details the development of the Penn Libraries’ Japanese Naval Collection, from its inception in a student’s scrapbook discovery to the iterative process of searching for and purchasing Imperial Japanese Navy Training Fleet materials and related items. It also encompasses promotion of the collection online by making digital facsimiles available and posting about its context and import on social media. Des Jardin and Williams re-envision the acquisitions, cataloging, digitization, and promotion process as the result of a network of individuals (both inside and outside the library) collaborating toward a shared vision of special collections. They integrate processes rather than functioning as a unidirectional assembly line in which component parts can be be passed down a pipeline. Through a network of individuals who share their complementary but unique skills and knowledge, formerly compartmentalized area studies materials can be more cohesively unified into a global collection and enhance the value of the library’s distinctive special and research collections in an increasingly international context

Accurate Spitzer infrared radius measurement for the hot Neptune GJ 436b

We present Spitzer Space Telescope infrared photometry of a primary transit of the hot Neptune GJ 436b. The observations were obtained using the 8 microns band of the InfraRed Array Camera (IRAC). The high accuracy of the transit data and the weak limb-darkening in the 8 microns IRAC band allow us to derive (assuming M = 0.44 +- 0.04 Msun for the primary) a precise value for the planetary radius (4.19 +0.21-0.16 Rearth), the stellar radius (0.463 +0.022-0.017 Rsun), the orbital inclination (85.90 +0.19-0.18 degrees) and transit timing (2454280.78186 +0.00015-0.00008 HJD). Assuming current planet models, an internal structure similar to that of Neptune with a small H/He envelope is necessary to account for the measured radius of GJ 436b.Comment: Accepted for publication in A&A on 21/07/2007; 5 pages, 3 figure

Impact of obesity on day-night differences in cardiac metabolism

An intrinsic property of the heart is an ability to rapidly and coordinately adjust flux through metabolic pathways in response to physiologic stimuli (termed metabolic flexibility). Cardiac metabolism also fluctuates across the 24-hours day, in association with diurnal sleep-wake and fasting-feeding cycles. Although loss of metabolic flexibility has been proposed to play a causal role in the pathogenesis of cardiac disease, it is currently unknown whether day-night variations in cardiac metabolism are altered during disease states. Here, we tested the hypothesis that diet-induced obesity disrupts cardiac diurnal metabolic flexibility , which is normalized by time-of-day-restricted feeding. Chronic high fat feeding (20-wk)-induced obesity in mice, abolished diurnal rhythms in whole body metabolic flexibility, and increased markers of adverse cardiac remodeling (hypertrophy, fibrosis, and steatosis). RNAseq analysis revealed that 24-hours rhythms in the cardiac transcriptome were dramatically altered during obesity; only 22% of rhythmic transcripts in control hearts were unaffected by obesity. However, day-night differences in cardiac substrate oxidation were essentially identical in control and high fat fed mice. In contrast, day-night differences in both cardiac triglyceride synthesis and lipidome were abolished during obesity. Next, a subset of obese mice (induced by 18-wks ad libitum high fat feeding) were allowed access to the high fat diet only during the 12-hours dark (active) phase, for a 2-wk period. Dark phase restricted feeding partially restored whole body metabolic flexibility, as well as day-night differences in cardiac triglyceride synthesis and lipidome. Moreover, this intervention partially reversed adverse cardiac remodeling in obese mice. Collectively, these studies reveal diurnal metabolic inflexibility of the heart during obesity specifically for nonoxidative lipid metabolism (but not for substrate oxidation), and that restricting food intake to the active period partially reverses obesity-induced cardiac lipid metabolism abnormalities and adverse remodeling of the heart

Dragging a polymer chain into a nanotube and subsequent release

We present a scaling theory and Monte Carlo (MC) simulation results for a flexible polymer chain slowly dragged by one end into a nanotube. We also describe the situation when the completely confined chain is released and gradually leaves the tube. MC simulations were performed for a self-avoiding lattice model with a biased chain growth algorithm, the pruned-enriched Rosenbluth method. The nanotube is a long channel opened at one end and its diameter $D$ is much smaller than the size of the polymer coil in solution. We analyze the following characteristics as functions of the chain end position $x$ inside the tube: the free energy of confinement, the average end-to-end distance, the average number of imprisoned monomers, and the average stretching of the confined part of the chain for various values of $D$ and for the number of monomers in the chain, $N$. We show that when the chain end is dragged by a certain critical distance $x^*$ into the tube, the polymer undergoes a first-order phase transition whereby the remaining free tail is abruptly sucked into the tube. This is accompanied by jumps in the average size, the number of imprisoned segments, and in the average stretching parameter. The critical distance scales as $x^*\sim ND^{1-1/\nu}$. The transition takes place when approximately 3/4 of the chain units are dragged into the tube. The theory presented is based on constructing the Landau free energy as a function of an order parameter that provides a complete description of equilibrium and metastable states. We argue that if the trapped chain is released with all monomers allowed to fluctuate, the reverse process in which the chain leaves the confinement occurs smoothly without any jumps. Finally, we apply the theory to estimate the lifetime of confined DNA in metastable states in nanotubes.Comment: 13pages, 14figure