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Phenyl
In organic chemistry, the phenyl group or phenyl ring is a cyclic group of atoms with the formula C6H5. Phenyl groups are closely related to benzene and can be viewed as a benzene ring, minus a hydrogen, which may be replaced by some other element or compound to serve as a functional group. Phenyl groups have six carbon atoms bonded together in a hexagonal planar ring, five of which are bonded to individual hydrogen atoms, with the remaining carbon bonded to a substituent. Phenyl groups are commonplace in organic chemistry.[1] Although often depicted with alternating double and single bonds, phenyl groups are chemically aromatic and show nearly equal bond lengths between carbon atoms in the ring.[1][2]Contents1 Nomenclature1.1 Etymology2 Structure, bonding, characterization 3 Preparation, occurrence, and applications 4 References 5 External linksNomenclature[edit] Usually, a "phenyl group" is synonymous to C6H5– and is represented by the symbol Ph or, archaically, Φ
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Organic Chemistry
Organic chemistry
Organic chemistry
is a chemistry subdiscipline involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.[1] Study of structure includes many physical and chemical methods to determine the chemical composition and the chemical constitution of organic compounds and materials. Study of properties includes both physical properties and chemical properties, and uses similar methods as well as methods to evaluate chemical reactivity, with the aim to understand the behavior of the organic matter in its pure form (when possible), but also in solutions, mixtures, and fabricated forms
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Petrochemical Industry
The petrochemical industry is concerned with the production and trade of petrochemicals. It directly interfaces with the petroleum industry, especially the downstream sector
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Nuclear Magnetic Resonance
Nuclear magnetic resonance
Nuclear magnetic resonance
(NMR) is a physical phenomenon in which nuclei in a magnetic field absorb and re-emit electromagnetic radiation. This energy is at a specific resonance frequency which depends on the strength of the magnetic field and the magnetic properties of the isotope of the atoms; in practical applications, the frequency is similar to VHF
VHF
and UHF
UHF
television broadcasts (60–1000 MHz). NMR allows the observation of specific quantum mechanical magnetic properties of the atomic nucleus. Many scientific techniques exploit NMR phenomena to study molecular physics, crystals, and non-crystalline materials through nuclear magnetic resonance spectroscopy
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Chemical Shift
In nuclear magnetic resonance (NMR) spectroscopy, the chemical shift is the resonant frequency of a nucleus relative to a standard in a magnetic field. Often the position and number of chemical shifts are diagnostic of the structure of a molecule.[1][2][3] Chemical shifts are also used to describe signals in other forms of spectroscopy such as photoemission spectroscopy. Some atomic nuclei possess a magnetic moment (nuclear spin), which gives rise to different energy levels and resonance frequencies in a magnetic field. The total magnetic field experienced by a nucleus includes local magnetic fields induced by currents of electrons in the molecular orbitals (note that electrons have a magnetic moment themselves). The electron distribution of the same type of nucleus (e.g. 1H, 13C, 15N) usually varies according to the local geometry (binding partners, bond lengths, angles between bonds, and so on), and with it the local magnetic field at each nucleus
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Aromatic Ring Current
An aromatic ring current is an effect observed in aromatic molecules such as benzene and naphthalene. If a magnetic field is directed perpendicular to the plane of the aromatic system, a ring current is induced in the delocalized π electrons of the aromatic ring.[1] This is a direct consequence of Ampère's law; since the electrons involved are free to circulate, rather than being localized in bonds as they would be in most non-aromatic molecules, they respond much more strongly to the magnetic field. The ring current creates its own magnetic field. Outside the ring, this field is in the same direction as the externally applied magnetic field; inside the ring, the field counteracts the externally applied field
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Atorvastatin
Atorvastatin, marketed under the trade name Lipitor among others,[1] is a member of the medication class known as statins, which are used primarily as a lipid-lowering agent and for prevention of events associated with cardiovascular disease
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Hypercholesterolaemia
Hypercholesterolemia, also called high cholesterol, is the presence of high levels of cholesterol in the blood.[1] It is a form of high blood lipids and hyperlipoproteinemia (elevated levels of lipoproteins in the blood).[1] Elevated levels of non-HDL cholesterol and LDL in the blood may be a consequence of an unhealthy diet, obesity, inherited (genetic) diseases (such as LDL receptor
LDL receptor
mutations in familial hypercholesterolemia), or the presence of other diseases such as type 2 diabetes and an underactive thyroid.[1] Cholesterol
Cholesterol
is one of three major classes of lipids which all animal cells use to construct their membranes and is thus manufactured by all animal cells. Plant cells do not manufacture cholesterol. It is also the precursor of the steroid hormones and bile acids. Since cholesterol is insoluble in water, it is transported in the blood plasma within protein particles (lipoproteins)
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Allergies
Allergies, also known as allergic diseases, are a number of conditions caused by hypersensitivity of the immune system to something in the environment that usually causes little or no problem in most people.[10] These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis.[2] Symptoms may include red eyes, an itchy rash, sneezing, a runny nose, shortness of breath, or swelling.[1] Food intolerances and food poisoning are separate conditions.[5][4] Common allergens include pollen and certain food.[10] Metals and other substances may also cause problems.[10] Food, insect stings, and medications are common causes of severe reactions.[3] Their development is due to both genetic and environmental factors.[3] The underlying mechanism involves immunoglobulin E antibod
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Polymer
A polymer (/ˈpɒlɪmər/;[2][3] Greek poly-, "many" + -mer, "parts") is a large molecule, or macromolecule, composed of many repeated subunits. Because of their broad range of properties,[4] both synthetic and natural polymers play essential and ubiquitous roles in everyday life.[5] Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA
DNA
and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers
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Molecular Orbital Theory
In chemistry, molecular orbital (MO) theory is a method for determining molecular structure in which electrons are not assigned to individual bonds between atoms, but are treated as moving under the influence of the nuclei in the whole molecule.[1] The spatial and energetic properties of electrons within atoms are fixed by quantum mechanics to form orbitals that contain these electrons. While atomic orbitals contain electrons ascribed to a single atom, molecular orbitals, which surround a number of atoms in a molecule, contain valence electrons between atoms
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Acid
An acid is a molecule or ion capable of donating a hydron (proton or hydrogen ion H+), or, alternatively, capable of forming a covalent bond with an electron pair (a Lewis acid).[1] The first category of acids is the proton donors or Brønsted acids. In the special case of aqueous solutions, proton donors form the hydronium ion H3O+ and are known as Arrhenius acids. Brønsted and Lowry generalized the Arrhenius theory to include non-aqueous solvents. A Brønsted or Arrhenius acid usually contains a hydrogen atom bonded to a chemical structure that is still energetically favorable after loss of H+. Aqueous Arrhenius acids have characteristic properties which provide a practical description of an acid.[2] Acids form aqueous solutions with a sour taste, can turn blue litmus red, and react with bases and certain metals (like calcium) to form salts
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Ethanol
Ethanol, also called alcohol, ethyl alcohol, and drinking alcohol, is a chemical compound, a simple alcohol with the chemical formula C 2H 5OH. Its formula can be written also as CH 3−CH 2−OH or C 2H 5−OH (an ethyl group linked to a hydroxyl group), and is often abbreviated as EtOH. Ethanol
Ethanol
is a volatile, flammable, colorless liquid with a slight characteristic odor. It is a psychoactive substance and is the principal type of alcohol found in alcoholic drinks. Ethanol
Ethanol
is naturally produced by the fermentation of sugars by yeasts or via petrochemical processes, and is most commonly consumed as a popular recreational drug. It also has medical applications as an antiseptic and disinfectant. The compound is widely used as a chemical solvent, either for scientific chemical testing or in synthesis of other organic compounds, and is a vital substance utilized across many different kinds of manufacturing industries
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Acid Dissociation Constant
An acid dissociation constant, Ka, (also known as acidity constant, or acid-ionization constant) is a quantitative measure of the strength of an acid in solution. It is the equilibrium constant for a chemical reaction known as dissociation in the context of acid–base reactions.[note 1] In aqueous solution, the equilibrium of acid dissociation can be written symbolically as: HA + H 2 O ↽ − − ⇀ A − + H 3 O + displaystyle ce HA + H2O <=> A^- + H3O^+ where HA is a generic acid that dissociates into A−, known as the conjugate base of the acid and a hydrogen ion which combines with a water molecule to make a hydronium ion
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Electronegativity
Electronegativity, symbol χ, is a chemical property that describes the tendency of an atom to attract a shared pair of electrons (or electron density) towards itself.[1] An atom's electronegativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus. The higher the associated electronegativity number, the more an element or compound attracts electrons towards it. The term "electronegativity" was introduced by Jöns Jacob Berzelius in 1811,[2] though the concept was known even before that and was studied by many chemists including Avogadro.[2] In spite of its long history, an accurate scale of electronegativity was not developed until 1932, when Linus Pauling
Linus Pauling
proposed an electronegativity scale, which depends on bond energies, as a development of valence bond theory.[3] It has been shown to correlate with a number of other chemical properties
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International Standard Book Number
The International Standard Book
Book
Number (ISBN) is a numeric commercial book identifier which is intended to be unique.[a][b] Publishers purchase ISBNs from an affiliate of the International ISBN Agency.[1] An ISBN is assigned to each separate edition and variation (except reprintings) of a publication. For example, an e-book, a paperback and a hardcover edition of the same book will each have a different ISBN. The ISBN is ten digits long if assigned before 2007, and thirteen digits long if assigned on or after 1 January 2007. The method of assigning an ISBN is nation-specific and varies between countries, often depending on how large the publishing industry is within a country. The initial ISBN identification format was devised in 1967, based upon the 9-digit Standard Book
Book
Numbering (SBN) created in 1966
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