Selective Dialkylation of a Doubly Linked Dicyclopentadiene Ligand and Research Paper

Selective Dialkylation of a Doubly Linked Dicyclopentadiene Ligand and the Ensuing Ruthenium Complexes - Research Paper Example The authors state the motivation behind such an approach as â€Å"While Ru3(CO)12 is an ideal starting material with regard to the cis to trans isomeric ratio formed around the doubly linked dicyclopentadienyl ligand, the CO ligand usually requires high heat or photolytic conditions and laborious chemicalsteps to remove it from the metal center. These chemical steps reduce the synthetic versatility of the resulting ruthenium complexes that contain a CO ligand† (Fier, et al., 2011). The paper concludes with a structure refinement of the obtained diruthenium complex which has the structural representation: Synthesis Route The reaction begins with the hydroxyl bromination of 4,4,8,8-tetramethyl-1,4,7,8-tetrahydro-s-indacene (1a; C2v symmetry) and 4,4,8,8-tetramethyl-1,4,5,8-tetrahydro-s-indacene (1b; C2h symmetry) by N-bromosuccinimide (NBS), NH4OAc and H2O/ Acetone. The dehydration of the resulting compound was done under anaerobic conditions in the presence of p-TsOH.H2O to yie ld the compounds 2 a,b. Reaction of 2a,b with MeMgBr in the presence of Ni-(dppf)Br2 (dppf = 1,1?-bis(diphenylphosphino)ferrocene) gave (C5H3Me)2(CMe2)2 (3a,b) in 31% yield. However, it was found that this compound 3 a,b did not react very well with RuCl3.3H20. Adding a bulkier alkyl group could lead to a specific 2,6 bonding making advantage of stearic repulsion with the methyl groups in the 4,8 position. Thus, the first reaction was modified to yield: Reaction of 4a,b with RuCl3 ·3H2O in MeOH (140  °C,15 min) gives a green-black heterogeneous mixture, with filtration of the mixture yielding a dark purple-black solid which was found to be diamagnetic. A subsequent X-ray crystallographic study of the new compound showed it to be the half-sandwich complex cis-{(?5-C5H2-(t-Bu))2(CMe2)2}Ru2(?-Cl)2Cl2 (5), containing RuII / RuII metal centers. The preferred way to synthesize 5 is to bypass the filtration and isolation step of the purple intermediate and to just remove the MeOH solve nt from the crude reactionmixture, add CHCl3, and heat to 80  °C for 15 min to give 5 in 28% yield (Scheme 2). The Structure of 5 shows a Ru?Ru single bond with a bond length of 2.7057(3) A, which would explain the diamagnetic nature of 5. Evidence for the RuII/RuII core is provided by the dissolution of the purple solid in MeCN to form cis-[{(?5-C5H2(t-Bu))2(CMe2)2}Ru2(MeCN)4(?-Cl)]+ (6), Complex 6 can also be synthesized by the reduction of 5 using Zn dust in MeCN and isolated in 62% yield (Scheme 3) The authors have successfully alkylated the 2,6-positions of the doubly linked dicyclopentadiene ligand 1a,b with either Me or tertbutylgroups. When the alkyl groups are tert-butyl groups, the resulting ligand reacts with RuCl3 ·3H2O to yield 5, the doubly linked analogue of [CpRuCl2]2 and [Cp*RuCl2]2. 5 can be reduced with Zn in MeCN to yield 6, an acetonitrile complex with a bridging chloro ligand. The bridging chloro ligand in 6 can be removed by the addition of AgOTf to yield 7, a ruthenium complex containing only the doubly linked dicyclopentadienyland acetonitrile ligands. Chin, R. M., Simonson, A., Mauldin, J., & Criswell, J. (2010). Organometallics , 29 (17), 3868?3875. Fier, P.

Coming of Age Essay Example for Free

Coming of Age Essay Around the world there are many themes that we find over and over in many cultures and from many periods in time. One of the reoccurring themes that everyone goes through in the lifetime is the theme of coming of age. This occurs when a young person goes through the transition from childhood to adulthood and has life experiences that matures a person. We all have experienced a coming of age story by reading them in books, seeing them on TV or in movies, or maybe even personal experiences based on ones culture. It’s clear that coming of age is a crucial element of our self-representations and conceptions. Generally, all of living is a process of coming of age as seen in the novel, Catcher in the Rye. Holden Caulfield, who is sixteen-year-old boy with the mind of a ten year old. He thinks of innocence as important in the beginning of the novel. But later on in the book, Holden slowly grows to be an adult. For example, when Holden gets soaking wet by rain when he is watching his little sister ride the carousal he â€Å"felt so damn happy all of a sudden†(213). This symbolizes Holden entering adulthood because he realizes the happiness in life. He realizes that he is too big for the carousel and is happy that his sister is happy. Holden’s childish personality continued to wash away as he reached a stage of maturity. Over the course of the novel, To Kill a Mockingbird, Scout is taken from a position of innocence, in which she believes that she is safe and that there aren’t many â€Å"bad people† in the world, to the position where she has witnessed some of the bad things that have happened but realizes that she is not entirely safe. That is tested at the end of the novel when Scout was attacked while walking home with her brother Jem. Similarities were show in The Adventures of Huckleberry Finn. Hucks maturity begins to grow as he first starts to show emotions toward a runaway slave, and by the end of the novel, has grown up to the point where, when Jim, is captured, Huck decides to give up playing games after Tom is shot to ensure that he would get medical attention that he needed. In an episode of Malcolm in the Middle it revolved around Malcolm trying to help his classmate Dabney get into a paintball match despite the resistance of Dabneys overbearing mom. Once Dabney unleashes years of repressed aggression, his mom comes around to try to drag him off. Dabney reacts back by saying â€Å" I’m no longer your little boy anymore. I’m your little man† showing that Dabney has matured and stands up and says what he believes. In the movie Edward Scissorhands, Edward is taken in by a family who he depends on. The family teach him how to think for himself so that one day he can gain the independence that is necessary for him to go out on his own. Edward living off of the familys support and trying things for himself is a coming of age process in itself. When he starts acting out and making his own decisions he is transitioning into an independent mindset that eventually allowed him to make the choice of living alone and fend for himself. Roman Catholics believe that Confirmation â€Å".. completes the process of initiation into the community and it matures the soul for the work ahead.. During confirmation God the Holy Spirit comes upon the person, accompanied by God the Father and God the Son, just as he did at Pentecost. †(Acts 2:1–4) Those who have been confirmed are called â€Å"Soldiers of God†. This refers to their spiritual duty to fight evil, darkness, and Satan. In Nigeria, young girls known as Iriabo spend several weeks in â€Å"fattening rooms† being pampered and wearing copper coils around their legs to restrict movement as part of a ritual marking their official transition into womanhood. In Senegal, Bassari boys undergoing the Kore rite and are taken into a sacred forest where they experience a symbolic death and a return to infancy, a state of ritual purity from where they are reborn as mature members of the community. (Hipple) Ultimately, the coming of age experience is a very much so significant time in ones life. People have to continue to find themselves and explore who they are even after the coming of age experience. It has lasting effects on a person as it has an impact on our dreams and desires that we want to fit into our world.

A Womans Place by Naomi Wolf :: Feminism

The True Woman "A Woman’s Place", the name of the commencement speech given by Naomi Wolf at the Scripps College graduation in 1992; contrasts the independent and the dependent woman. In today’s society, there are two different types of women: the woman who has a good head on her shoulders and knows where she is going in the world, and the woman who seeks dependence within the masculine world. Just as they were thirty years ago, women are still not considered to be equal to men. They are more or less looked at as being second to men. Naomi Wolf is a Jewish feminist writer who supports the independent woman. She was a Rhodes Scholar at Oxford University and graduated from Yale in 1984. Since then, Wolf has written two books that she is very well known for. She wrote her first book, titled The Beauty Myth, when she was twenty-nine years old. This book talks about women and how they feel beauty is one of the most important factors that will get you anything or anywhere. Her second book Fire With Fire was written in 1993. This book is about women taking control and not being victimized. Wolf is said to be a headstrong feminist that really believes in women’s power. In her commencement speech she mentions four factors of knowledge that she believes are mandatory for women to remedy. Her idea of a true or good woman is a strong woman who knows what she wants from life, is out to succeed, and will survive. An untrue or bad woman is a lady that is weak, that has a tendency to get run over, and has no real ambition for what she wants to do with her life. Wolf says that in order to become a headstrong, successful woman, one needs to redefine becoming a woman. Women have many different ways to clarify becoming women. According to Wolf, men have it a lot easier; however, most people in society would not agree with this. Boys have just as hard of a time becoming a man as a girl does becoming a woman. One might believe that Wolf is trying to say a women needs to redefine herself in order to have a place to start, so she can figure out what she wants to be and where she wants to go.

Western and Eastern Architecture

Culture and traditions have been an important component in influencing the development and creation of both Chinese and Roman architecture. It is through these norms that standards and perceptions of beauty are created. Each facet is deeply rooted in its ability to showcase the variety of actions from the structural foundations towards internal arrangements. These ideas then constitute the relevant ideas that have transformed the way construction and design is manifested within the boundaries of each culture. In the end, these differences created similarities and differences in approaches that harnessed each one’s individuality and contribution to the world today. On one aspect, we see the Roman architecture which bases its definition and construction of structures and buildings under a prescribed standard and format. These prevailing concepts have evolved through time under the pioneering Roman thinkers during the time. Under this process, a system for construction was introduced with by using important tenets such as geometry and mathematics that denote synchronization and order of things. Through this, the Romans advocate the relevance of proportion, both in exterior and interior design. It is through this that they are able to create their own distinct mark such as the formation of tablinum, atrium and peristyle courtyards. Comparing this with Chinese architecture, it can be argued that the overall design and architecture is considered to be free flowing. The plan captures the relevance of aesthetics by capturing the elements of nature and blending them accordingly with the both in the interior and exterior of the structure. It is through these actions that the idea of harmonization and being one with the overall surroundings becomes important. In addition, incorporation of natural elements such as trees and plants are also some distinct facets practiced by the Chinese. Moreover, adopting relative natural elements to these structures also necessitates generating freedom and ability to garner wholeness. Seeing these relevant differences, there are also similarities between these distinct approaches in viewing architecture and design. One relevant parallelism that can be seen in this process is that both approaches denote a system and standard of measurement and design. Though the Chinese may not be too strict about this and often tries to cover this up, the two ideas exhibit relevant attention to such facet and helps them apply significant ideas that contribute the creation of magnificent structures. Another significant similarity between these two styles is their ability to dig deep within their cultural backgrounds and affiliations to come up with standards and processes of how to construct and design structures. Take for example, the Chinese model for Buddhism and its relevance with being one with nature (Zen) has been the core concepts that generate such buildings. On the other hand, for the Romans, it is their constant passion for architecture and magnificent design that has enabled them to come up with ideas such as Coliseums, arched domes, and public baths. These similarities in turn foster their individuality as each approach makes their distinct mark in the overall application and design process. It may be true that each one possesses similar building foundations however; each one targets a different path in its application. With their ability to fabricate unique sets of designs, both the Chinese and Romans were able to create a framework that is encompassing and facilitative towards the growth of their relative inventiveness and capture the essence of their cultural heritage and practice.

Sarnath

The Buddha went from Bodhgaya to Sarnath about 5 weeks after his enlightenment. Before Gautama (the Buddha-to-be) attained enlightenment, he gave up his austere penances and his friends, the Pancavaggiya monks, left him and went to Isipatana. [4] After attaining Enlightenment the Buddha, leaving Uruvela, travelled to the Isipatana to Join and teach them. He went to them because, using his spiritual powers, he had seen that his five former companions would be able to understand Dharma quickly.While travelling to Sarnath, Gautama Buddha had to cross the Ganges. Having no money with which to pay the ferryman, he crossed the Ganges through the air. When King Bimbis ¤ra heard of this, he abolished the toll for ascetics. When Gautama Buddha found his five former companions, he taught them, they understood and as a result they also became enlightened. At that time the Sangha, the community of the enlightened ones, was founded. The sermon Buddha gave to the five monks was his irst sermon, called the Dhammacakkappavattana Sutta.It was given on the full-moon day of Asalha PuJa. [5] Buddha subsequently also spent his first rainy season at Sarnath[6] at the Mulagandhakuti. The Sangha had grown to 60 in number (after Yasa and his friends had become monks), and Buddha sent them out in all directions to travel alone and teach the Dharma. All 60 monks were Arahants. Several other incidents connected with the Buddha, besides the preaching of the first sermon, are entioned as having taken place in Isipatana.Here it was that one day at dawn Yasa came to the Buddha and became an Arahant. [7] It was at Isipatana, too, that the rule was passed prohibiting the use of sandals made of talipot leaves. [8] On another occasion when the Buddha was staying at Isipatana, having gone there from R ¤Jagaha, he instituted rules forbidding the use of certain kinds of flesh, including human flesh. [9] Twice, while the Buddha was at Isipatana, M ¤ra visited him but had to go away discomfited. [10]

How to Measure Motion in Plate Tectonics

How to Measure Motion in Plate Tectonics The lithospheric plates are the sections of Earths crust and upper mantle that move- very slowly- over the lower mantle below. We know that these plates move from two different lines of evidence- geodetic and geologic- which allow us to trace their movements back in geologic time. Geodetic Plate Motion Geodesy, the science of measuring the Earths shape and positions on it, allows us to measure plate motion directly using GPS, the Global Positioning System. This network of satellites is more stable than the Earths surface, so when a whole continent moves somewhere at a few centimeters per year, GPS can tell. The longer we record this information, the more accurate it becomes, and in much of the world, the numbers are already quite precise. Another thing GPS can show us is tectonic movements within plates. One assumption behind plate tectonics is that the lithosphere is rigid, and indeed that is still a sound and useful assumption. But parts of the plates are soft in comparison, like the Tibetan Plateau and the western American mountain belts. GPS data helps us separate blocks that move independently, even if only by a few millimeters per year. In the United States, the Sierra Nevada and Baja California micro-plates have been distinguished this way. Geologic Plate Motion: Present Three different geologic methods help determine the trajectories of plates: paleomagnetic, geometric, and seismic. The paleomagnetic method is based on the Earths magnetic field. In every volcanic eruption, iron-bearing minerals (mostly magnetite) become magnetized by the prevailing field as they cool. The direction in which theyre magnetized points to the nearest magnetic pole. Because oceanic lithosphere forms continuously by volcanism at spreading ridges, the whole oceanic plate bears a consistent magnetic signature. When the Earths magnetic field reverses direction, as it does for reasons not fully understood, the new rock takes on the reversed signature. Thus most of the seafloor has a striped pattern of magnetizations as if it were a piece of paper emerging from a fax machine (only its symmetrical across the spreading center). The differences in magnetization are slight, but sensitive magnetometers on ships and aircraft can detect them. The most recent magnetic-field reversal was 781,000 years ago, so mapping that reversal gives us a good idea of plate movements in the most recent geologic past. The geometric method gives us the spreading direction to go with the spreading speed. Its based on the transform faults along the mid-ocean ridges. If you look at a spreading ridge on a map, it has a stair-step pattern of segments at right angles. If the spreading segments are the treads, the transforms are the risers that connect them. Carefully measured, these transforms reveal directions of spread. With plate speeds and directions, we have velocities that can be plugged into equations. These velocities match the GPS measurements nicely. Seismic methods use the focal mechanisms of earthquakes to detect the orientation of faults. Although less accurate than paleomagnetic mapping and geometry, these methods are useful for measuring plate movements in parts of the globe that arent well mapped and have fewer GPS stations. Geologic Plate Motion: Past We can extend measurements into the geologic past in several ways. The simplest one is to extend paleomagnetic maps of the oceanic plates out from the spreading centers. Magnetic maps of the seafloor translate precisely into age maps. These maps also reveal how the plates changed velocity as collisions jostled them into rearrangements. Unfortunately, the seafloor is relatively young, no more than about 200 million years old, because it eventually disappears beneath other plates by subduction. As we look deeper into the past, we must rely more and more on paleomagnetism in continental rocks. As plate movements have rotated the continents, the ancient rocks have turned with them, and where their minerals once indicated north, they now point somewhere else, toward apparent poles. When you plot these apparent poles on a map, they appear to wander away from true north as rock ages go back in time. In fact, north does not change (usually), and the wandering paleo-poles tell a story of wandering continents. Together, the methods listed above allow us to produce an integrated timeline of the movement of the lithospheric plates, a tectonic travelogue that leads smoothly up to the present.

Stakeholder Society essays

Stakeholder Society essays Social equality has long been a dream of many Americans. It would be wonderful to live in a society where everyone had equal or nearly equal opportunities, but the United States will never be the land of equal opportunity because it is just not going to happen because we have been socially stratified for too long to ever be equal. However, as Ackerman and Alstott propose in The Stakeholder Society, we may be able to offer Americans an equal monetary offering from the government, but is this going to work? Ackerman and Alstott propose to simply raise taxes 2% and give every American eighty thousand dollars sometime in there twenties, considering that they are stable minded and graduated from high school. Recipients would not receive the eighty thousand dollars in one lump sum, but over a period of a few years. When the recipient dies, if they have sufficient funds, they repay the eighty thousand dollars back to the government where it will be used for redistribution. At first, this sounds like a great idea, however, there are many underlying problems. First of all, there are way too many irresponsible people who will blow their money on toys such as new cars, electronics, or on drugs and become drug addicts. Giving a check for twenty thousand dollars to a twenty-five year old and telling them that they can do whatever they please with it is pretty brave. Giving large handouts will also teach people to spend irresponsibly and not manage their money. They will not know what to do when the money runs out and they are still earning seven dollars an hour at some job that they hate. Instead of giving any twenty-some year old American eighty thousand dollars, I believe the government should provide a program to provide funding government funding for college. Every American should be able to go to college for free. This is the time when many people accrue large debts through loans and living expenses bu ...