Introduction to Chemistry PDF

Introduction to Chemistry NSG 741: Genetics, Chemistry, and Physics of Anesthesia School of Nursing Why Chemistry and Physics? The foundation of anesthesia practice is scaffolded by an elegant framework of chemical and physical science....

Introduction to Chemistry NSG 741: Genetics, Chemistry, and Physics of Anesthesia School of Nursing Why Chemistry and Physics? The foundation of anesthesia practice is scaffolded by an elegant framework of chemical and physical science. Chemistry is the study of the composition, properties, and structure of matter at the atomic and molecular levels, and it describes how matter behaves when it reacts with other matter. Physics is a field of study that describes the motion, mechanics, force, and energy of matter, and it examines how matter behaves through space and time. School of Nursing Why Chemistry and Physics? Taken together, these complex fields explain such actions as pressure, flow, diffusion, expansion, contraction, and other processes that are intimately intertwined with the delivery of anesthetics. To understand these laws and theories is to understand the how and why of anesthesia practice; it provides rationale for clinical interventions and allows for the manipulation of powerful processes to optimize patient care. School of Nursing  General Chemistry The universe is composed of two main constituents: matter and energy. Energy applies to physics. Matter is the tangible composition of the universe that may be solid, liquid, gas, or plasma. Solids are defined as materials that resist changes in shape and volume. Liquids are fluids that exhibit minimal to no compressibility and may change volume with changes in pressure and temperature. Gases are also fluids but are compressible School and easily of Nursing change volume with changes in pressure and  So, what is chemistry? Chemistry is the study of matter and the changes it undergoes. Physical chemists strive to discern models needed to understand chemical systems from a theoretical framework. Inorganic chemists study substances that are derived from all elements except carbon. Organic chemists study compounds based on carbon. Biochemists study the chemistry that occurs in living systems. Chemical vs. physical changes. A chemical change results in the formation of a new substance. A physical change changes the state of the substance but not the identity of the substance. School of Nursing States of Matter Three commonly encountered states of matter. Solids—definite shape and volume Liquids—definite volume but indefinite shape Gases—indefinite shape and volume Transitions between states of matter. Melting—conversion of a solid into a liquid Freezing—conversion of a liquid into a solid Vaporization—conversion of a liquid into a gas Condensation—conversion of a gas into a liquid Deposition—conversion of a gas into a solid (water vapor to ice) Sublimation—conversion of a solid directly School intoofaNursing gas  The Atom Atoms are the basic building blocks of matter and are comprised of three particles: Protons (Z)—positively charged with a mass of approximately 1 atomic mass unit (amu). Neutrons—electrically neutral and have a mass of approximately 1 amu. Electrons—negatively charged and have a much smaller mass than protons and neutrons, typically ignored to determine mass. Atomic number (Z)—number of protons in the nucleus. Determines the identity of the atom, name ofofthe School Nursing element. The Atom Neutron number (N)—number of neutrons in the nucleus. Mass number (A)—sum of the atomic number and neutron number. Can never be smaller than the atomic number. Atomic weight? Average amu. For example, C is 12.011 (C-12, C-14). School of Nursing The Atom Protons and neutrons are bound together by the strong nuclear force into an incredibly dense structure called the nucleus at the center of the atom. The nucleus of an atom is about 100,000 times smaller than the atom Pea in the center of a stadium. Elements are always electrically neutral, so each atom must have an equal number of protons and electrons. The electrons orbit the nucleus in the electron cloud. School of Nursing  The Atom Electrons travel in predictable orbit patterns called shells. Each shell is filled (one set) before the next outer shell can begin to fill. The outermost shell electrons are valence electrons. This is where you will see a change in number. An incomplete shell allows an atom to react with another atom. A full shell makes the atom inert (non-reactive). The electron dot structure (Lewis) is used to denote bonding by dots or lines. Electron shells are further divided into subshells School of Nursing which are Dalton’s Atomic Theory Postulates of John Dalton’s atomic theory: Elements are composed of tiny, indivisible particles called atoms; all atoms of a given element are identical and unique to that element. Compounds are formed by bonding different atoms together in a fixed ratio. Chemical reactions do not create, destroy, or change atoms into atoms of other elements; they cause atoms to recombine into new substances. School of Nursing  Dalton’s Atomic Theory Dalton based his theory on two important laws: Law of conservation of mass—no detectable change in the total mass occurs during a chemical reaction. Law of definite proportions—different samples of a pure compound always contain the same elements in the same proportion by mass. He also discerned the law of multiple proportions—some elements can combine to give more than one compound. From a modern standpoint, Dalton’s law is incomplete, and in some cases, just plainly wrong, but it provided a working foundation that guided current and future scientists (He didn’t know of isotopes). School of Nursing The Periodic Table of the Elements Modern periodic table is organized according to the periodic repetition of chemical and physical properties. Each box contains the chemical symbol of an element, along with its atomic number and average atomic mass. Elements are listed in order of increasing atomic number, so each successive element has one additional proton. Each row is called a period. Periods represent adding electrons to quantum energy levels in the atom. School of Nursing The Periodic Table of the Elements Vertical columns are called groups or families. Elements in each group have similar chemical and physical properties. Simplest system numbers the groups from 1 to 18, but the authors prefer a system that groups by Roman numerals from one to eight, along with a letter (A or B). 8A or 18 are the noble gases – colorless, odorless, reluctant to combine. School of Nursing Average Atomic Weights & Classifications Atomic weights listed on the periodic table are weighted averages of the atomic masses of the naturally occurring isotopes of that element. Classifying Elements on the Periodic Table Classify as representative, transition, or inner transition. In the older numbering system: Representative elements have a group number with an A. Transition elements have a B designation in their group number. Inner transition elements are the “footnotes” School of Nursing School of Nursing Metals vs. Nonmetals Metals (do ionize) Nonmetals What are they? Solids, liquids, or gases Shiny, solid, ductile, Poor conductors malleable, conductive Chemical reactivity: Chemical reactivity: Gain electrons Donate electrons School of Nursing Ions & Elements Ions are atoms or groups of atoms bonded together that have a net electrical charge, which is attained by adding or removing electrons. An atom with a positive charge (lost electrons) is a cation (element + “ion”). An atom with a negative charge (gained electrons) is an anion (“ide” suffix). Elements contain only a single type of atom. Ionization energy: the minimum amount of energy required to remove the most loosely bound electron. School of Nursing Compounds Compounds contain two or more kinds of atoms. Bonded by two types of chemical bonds. Covalent: Molecules (molecular compounds) are a group of two or more atoms chemically bonded together into a discrete unit by covalent bonds and are electrically neutral. Atoms in the compound share outer valence electrons and become a discrete unit called molecular compound. Electrostatic: Ion-ion, ion-dipole, dipole-dipole (Ionic compounds). Contain positively charged ions and negatively charged ions and have no identifiable discrete units. School of Nursing Mass Spectrometer A mass spectrometer is used to determine the mass of an atom or molecule. Sample is introduced into the instrument. Injection port is maintained under conditions of high temperature and low pressure. Sample diffuses into the ionization sector and is bombarded with high-energy electrons, which knocks one electron off, giving the sample a molecular ion. In the magnetic sector, external magnets are arranged so as to push the molecular ion in a curved path. By manipulating the strength of the external magnets, you can scan to find the atomic (or molecular) mass of the sample. School of Nursing School of Nursing Moles A mole is an amount of a substance that contains exactly as many particles as there are in exactly 12 g of carbon-12. This number is often called Avogadro’s number and is equal to 6.02 × 1023 particles/mol. Avogadro’s number has two units (particles and moles), so it is a conversion factor between particles and moles. School of Nursing Molar Mass (Molecular Weight) The molar mass (expressed in g/mol) of an element is equal to its atomic mass (expressed in amu). For molecules, the molar mass is equal to the sum of the masses of the component atoms. Since molar masses have units of grams and moles, they are conversion factors between grams and moles. 1 mole of molecules = 1 dozen of eggs A dozen horses have a different weight than a dozen dogs, but in each case, you have a dozen animals. Similarly, a mole of oxygen gas has a different weight than a mole of water, but in each case, you have 6.02 × 1023 particles/mol. School of Nursing What is a Mole? A mole is a unit that represents 6.02 × 10²³ particles (atoms, molecules, or ions). This number is called Avogadro’s number. This specific quantity was chosen because it is the number of atoms in exactly 12 grams of carbon- 12. The mole serves as a conversion factor between the number of particles and the amount of substance in moles. School of Nursing Molar Mass and Atomic Mass The molar mass (g/mol) of an element is numerically equal to its atomic mass (amu). Example: The atomic mass of oxygen (O) is 16 amu. This means 1 mole of oxygen atoms has a mass of 16 g. School of Nursing Molar Mass of Molecules For molecules, the molar mass is the sum of the atomic masses of all the atoms in the molecule. Example: Water (H₂O): Hydrogen = 1 amu, Oxygen = 16 amu So, H₂O = (2 × 1) + 16 = 18 g/mol. This means 1 mole of water molecules weighs 18 g. School of Nursing Comparing Moles to Dozens A mole is like a dozen but on a much larger scale. A dozen eggs and a dozen elephants have different weights, but both contain 12 items. Similarly, a mole of water and a mole of oxygen gas have different weights, but both contain 6.02 × 10²³ School of Nursing molecules. Moles as Conversion Factors Particles ↔ Moles: Use Avogadro’s number. Example: 1 mole of H₂O = 6.02 × 10²³ molecules of H₂O. Grams ↔ Moles: Use molar mass. Example: 18 g of H₂O = 1 mole of H₂O. School of Nursing Isotopes Atoms of the same element can differ. These different atoms of the same element are called isotopes. They are different from each other by having different number of neutrons. Same atomic number but with different numbers of neutrons. Since the neutron number is different, their mass number also differs. School of Nursing Isomers Isomers are molecules that have the same chemical formula but different structures. The number and type of atoms and bonds are the same in isomers, but the arrangement of the atoms is different. Structural isomers have the same molecular formula, but their atoms are located in different places (Isoflurane). Stereoisomers are molecules that have a similar geometric arrangement of atoms but differ in their spatial position. Stereoisomers may be enantiomers or School of Nursing diastereomers. Isomer Example School of Nursing Isomers Enantiomers are mirror images of one another, cannot be superimposed, and possess similar chemical and physical properties. Racemic epi Enantiomers are optically active and can rotate polarized light in a clockwise fashion (denoted by the prefix + or dextro) or counterclockwise fashion (denoted by the prefix − or levo). Racemic chemical compositions contain 50% of the levo form of the isomer and 50% of the dextro form of the isomer. Racemic epinephrine used to treat laryngeal edema is an example of a racemic mixture. School of Nursing School of Nursing  Enantiomer Same chemical formula, similar structure, but not superimposable. School of Nursing Physical and Chemical Properties and Changes Physical changes occur without changing the chemical makeup of the substance undergoing the changes. Chemical changes always result in the formation of chemically different substances. Physical properties can be observed or measured without changing the chemical makeup of the substance. Two categories: intensive (integral to the material- color) and extensive (depend on the sample size- mass). Chemical properties describe the types of chemical changes the material tends to undergo (flammability). School of Nursing Chemistry Concepts Pure Substances and Mixtures Pure substances are materials that cannot be physically separated into simpler components. Mixtures are comprised of two or more pure substances and can be resolved into simpler components through physical processes. Homogeneous mixtures are uniform in chemical and physical properties. Heterogeneous mixtures exhibit distinct phase boundaries between their components. School of Nursing  Bonds, Chemical Nomenclature, & Functional Groups NSG 741: Genetics, Chemistry, and Physics of Anesthesia School of Nursing  Intermolecular Forces Determined by chemical bonding but directly impact the macroscopic properties of a sample, such as the state of matter under a given set of conditions and the tendency of a liquid to evaporate. Also control key microscopic and chemical processes such as transcription of DNA and recognition of a substrate by an enzyme. Electrostatic in nature because they arise due to the attraction of opposite charges. Since most of the volume of an atom or molecule is an electron cloud, the organization of electrons as chemical bonds between atoms in a molecule, as well as the three-dimensional arrangement of the electron clouds in space, is responsible for the type and strength of the intermolecular forces. Coulomb’s Law states that the force of attraction between two School of Nursing charges increases the closer they become to each other. Lewis Structures Nonmathematical models that allow us to qualitatively describe the chemical bonding in a molecule and then gain insights about the physical and chemical properties we can expect of that molecule. Atoms are represented by their chemical symbol. Lines between atoms represent shared pairs of electrons in covalent bonds. Valence electrons not used for covalent bonds are lone pairs and are represented as pairs of dots on the atom. School of Nursing Balancing Chemical Equations 2H2 + O2 > 2 H2O HCO3 + H H2CO3 C2H4 + 3 O2 > 2 CO2 + 2 H2O School of Nursing Valence Shell Electron Pair Repulsion (VSEPR) Theory Atoms are bound into molecules by shared pairs of electrons, which have like charges and repel each other, trying to get as far apart in space as is geometrically possible. This creates linear, trigonal planar, tetrahedral, bent, and pyramidal geometric shaping. Electron repulsion forces. School of Nursing Valence Bond Theory A covalent bond results from sharing one or more pairs of electrons between two atoms through the overlap of their valence electron clouds. The wave functions overlap and electrons on both atoms are guided by a compound wave function that encompasses both nuclei. The presence of electrons between the two nuclei shields them from one another, thereby reducing the magnitude of the Coulombic repulsive force and stabilizing the molecule by lowering its overall energy. School of Nursing Bond Length and Bond Energy As atoms come together, the degree of attraction among the nuclei and electrons increases and the energy of the molecule decreases, eventually Unstabl Unstabl reaching a minimum value e e and becoming more stable. There is an ideal bond length (distance between the nuclei) at which the energy is at a minimum and Stable the molecule is at maximum stability. School of Nursing Ionic Bonds Result from Coulombic attraction between oppositely charged ions. In the solid state, the oppositely charged ions settle into a highly organized crystalline lattice, in which every cation is attracted to every anion. Generally stronger than covalent bonds* and nearly all are solid at room temperature and pressure. (*Chemists argue ionic is stronger.) This type of bond involves the complete transfer of valence electrons from one atom to another. This leaves one atom with a negative and one with a positive charge. School of Nursing School of Nursing Covalent Bonds Result from sharing one or more pairs of electrons, giving each atom access to eight electrons. Shared by bringing atoms close enough so that their electron orbitals overlap—electron shells are divided into subshells, and subshells are divided into orbitals. An orbital is a mathematical function that describes the wave nature of an electron, so orbitals can be added together. Single, double, or triple bond is possible. School of Nursing School of Nursing Electronegativity & Polar Covalent Bonds Electronegativity Propensity of an atom to pull electrons toward itself; nonmetal (F) has high electronegativity. Proximity to F in the periodic table is directly proportional to the amount of electronegativity. Polar Covalent Bonds Exist when atoms of different electronegativity bond together. The greater the difference in electronegativity, the more polar the bond. Bonding electrons spend more time around the more electronegative atom because it is the nature of an electronegative atom to pull electrons toward itself. School of Nursing Polar Covalent Bonds Electrons are still shared but tend to remain closer to one atom than the other. The larger oxygen nucleus attracts the electrons with greater attraction than the smaller hydrogen nuclei. This creates a dipole. Water (more negative near oxygen) This creates the hydrophilic and hydrophobic environment of water. School of Nursing Electrostatic Bonds Electrostatic bonds are made by the attraction of electrons between atoms due to electron distribution. Follow the general rule of “opposites attract,” with negative charges attracting positive charges. School of Nursing Ion-Ion Bonding Ion-to-ion bonds are the strongest of the electrostatic bonds. These bonds are not directional and occur anywhere along the outer electron shell of an atom. Molecules with ionic bonds have high melting and boiling points. Sodium chloride (table salt) is an example of ion-to-ion bonding. In order to melt or boil, then, the bond must be broken. The stronger the bond, the harder this is to do, and thus, the boiling point will be higher. School of Nursing Ion-Dipole Bonding Attractions between ion and polar molecule. Only partial charges involved. Allows ionic solids to dissolve in water. H2O and NaCl. School of Nursing Hydrogen Bonding Dipole-Dipole Bonding The hydrogen atom is stripped of so much of its electron cloud that it appears as a tiny, focused point of positive charge that is highly attractive to ions with a partial negative charge. Arguably the most important of the intermolecular forces. This causes water to School of Nursing have surface tension. Van der Waals Forces: London Dispersion Forces & Dipole-Dipole Attractions Very weak but very common intermolecular force that holds molecules of the same type together. Partial positive and negative charges exist at different parts of the molecule at any time. Electron-rich areas of one molecule attract electron-poor areas of another. London dispersion forces at very low temperatures allow oxygen and nitrogen to become liquids. School of Nursing Molecular Bond Strength Strongest to Weakest Covalent > Ionic > Polar Covalent > Hydrogen bond > Van der Waals However, we are biologists more than chemists. We want to know what is happening or will happen in the human body system. Our bodies are mostly water (aqueous); thus, covalent bonds tend to be stronger in this water-based environment. School of Nursing Bond Breaking Bond energy is the amount of energy needed to make or break a bond. Energy is released when a bond is formed, and energy is consumed when a bond is broken. The energy released when a bond is formed is the same amount of energy required to break that same chemical bond. Short bonds, such as covalent bonds, tend to possess greater bond energies than longer, electrostatic bonds. When molecular bonds are broken, new molecular bonds are often formed, and energy is released. Bond energies are measured as an enthalpy change. School of Nursing Enthalpy Enthalpy is the total amount of energy possessed by a system. A system can be on the atomic scale or the macroscopic scale. The enthalpy of a system is the total of all kinetic and potential energy. The stored, or potential, energy includes its height in relation to the force of gravity and the energy stored in the bonds of its molecules, atoms, and even subatomic particles. All movement, as well as stored energy, must be accounted for and summated to know the enthalpy of a system. Change of energy (ΔH) rather than total energy (enthalpy) of a system is measured. School of Nursing Electrolytes An electrolyte is a substance that dissolves in water to give a solution that conducts electricity. A nonelectrolyte is a substance that dissolves in water to give a solution that does not conduct electricity. The few ionic compounds that readily dissolve in water are electrolytes because they separate into ions that freely and independently move around in the solution. Since they are free to move around in the solution, the solution conducts electricity. School of Nursing Electrolytes Molecular compounds are nonelectrolytes, unless they have acid or base properties. Tap water conducts electricity because it contains a fair concentration of several electrolytes. Pure water, on the other hand, is a nonelectrolyte and is a very poor conductor of electricity. School of Nursing Surface vs. Underground Mining School of Nursing Functional Groups Organic molecules have two parts: Carbon backbone that is relatively inert (C has four valence electrons!). One or more functional groups. A functional group is a set of atoms bonded together in a specific way. More bonds are typically stronger bonds. School of Nursing Functional Groups Functional groups largely define the chemical and physical properties of the compound. You can expect molecules with similar functional groups to have similar physical and chemical properties. Chemists prepare new potential medications by synthesizing derivatives of known compounds by manipulating the functional groups, attempting to fine-tune their physiological properties. Most medications are organic molecules - the functional group reacts/targets a biological system. Different combinations of functional groups School of Nursing form the basis Functional Groups An important aspect of the structure of a molecule relates to how the body will degrade the molecule on consumption. The molecules are broken down by 2 phases of metabolism. Phase I reactions make the molecule more polar. Phase II reactions take the polar molecule and conjugate it to other more polar molecules. The new molecule is tagged to assist with excretion. This is important to your understanding of onset, duration, action of medications. School of Nursing  Hydrocarbon Functional Groups School of Nursing Hydrocarbon Functional Groups Bond-Line Structures (Molecular Graphs) Lines represent the carbon-carbon bonds. A carbon atom is located wherever the molecular graph terminates or changes direction. Every carbon is bonded to enough hydrogen atoms to satisfy the octet rule. Almost always means every carbon atom has four covalent bonds. Hydrogen atoms are rarely included in the structure. School of Nursing Hydrocarbon Functional Groups Organic Nomenclature: IUPAC Rules Name the longest chain as the parent alkane. Name any substituent alkyl groups in alphabetical order. Use multipliers to indicate the number of identical substituents: di = 2, tri = 3, tetra = 4, penta = 5, etc. Number the parent chain (begin at one end, not in the middle), and indicate substituent position(s) with lowest possible numbers (called locants). Numbers are separated from letters by hyphens and from numbers by commas. School of Nursing Alkanes (C-C) Also known as paraffins; “ane” suffix. Simplest of the organic compounds (C + H). Characterized by carbon-carbon single bonds; hydrophobic. Are the carbon backbone for other functional groups. Methane (CH4) is the simplest alkane. Ethane (CH3–CH3) is the next member of the alkane family. Normal alkanes have a linear chain of carbon atoms with no branching. School of Nursing Alkyl Groups Very reactive. Occur when a hydrogen atom is removed from an alkane. Named by replacing “ane” on the alkane name with “yl”. Generally symbolized by R. R group is the carbon backbone of the molecule (focus more on functional group and not R) As the R group becomes larger and bulkier, it has an impact on the chemical and physical properties of the functional groups present (more hydrophobic). School of Nursing Cycloalkanes & Saturation Cycloalkanes Named by adding the prefix “cyclo” to the parent name. Saturated Compounds Saturated molecules contain the maximum number of hydrogen atoms for a given number of carbon atoms. Carbon can have 4 Hydrogens ats satisfied. Forming rings or double bonds “costs” hydrogen atoms. Alkenes and cycloalkanes have fewer hydrogen atoms per carbon atom than alkanes. Compounds that contain double bonds or rings are called School of Nursing unsaturated. Alkenes (C=C) Also known as olefins. Have a carbon-carbon double bond functional group. Simplest is ethene (pictured). The geometry around alkene carbons is trigonal planar. The main functional group always gets the lowest number. Very symmetrical structure is capable of isomerism. School of Nursing Alkenes Reactions Hydrogenation In the presence of an appropriate catalyst (such as finely divided platinum metal), hydrogen gas reacts with an alkene to form an alkane. Each of the alkene carbons gets a bond to a hydrogen atom. During this process, double-bond electrons are used to form one of these new bonds, and the bonding electrons from the hydrogen molecule are used to form the other. Polymerization In the presence of a suitable catalyst the double-bond electrons can be used to stitch together many alkene molecules into immensely long alkanes. The length of the chain depends on the reaction conditions — the longer the chain, the denser and strongerSchool of Nursing the polymer. Alkynes (C≡C) Also known as acetylenes. Have a carbon-carbon triple bond functional group. Relatively rare in medical settings. Simplest is ethyne (more commonly known as acetylene). Named by adding the suffix “yne” and following the normal IUPAC rules. School of Nursing Aromatics Sometimes called arenes. Have a functional group called a benzene ring with single, double, or triple bonds. Very common in nature because they are especially stable. Frequently a structural element in medications. Benzene is the archetype aromatic compound and has the molecular formula C6H6. School of Nursing Aromatics In naming aromatic compounds, you may name the benzene ring as the parent or as a substituent, depending on which strategy is more convenient. When a benzene ring is a stick-on group, it is called a phenyl group. Aromatic compounds very frequently have common or trivial names. When a cyclic hydrocarbon is missing a hydrogen on any carbon atom, it becomes a “aryls” (reactive). 2,6-DIISOPROPYLPHENOL School of Nursing Organohalogen Compounds Organic compounds that contain one or more halogen atoms (F, Cl, Br, I). If the parent compound is an alkane, introduction of a halogen affords a haloalkane. Haloalkanes are also called alkyl halides. If the parent compound is benzene, the halogenated derivatives are called aryl halides. The generic formula of an alkyl halide is R-X, where R is a generic alkyl group and X is a generic halide. School of Nursing Organohalogen Compounds The IUPAC rules name organohalides as alkanes with halogen substituents. The halogens are named as halo groups: fluoro, bromo, chloro, and iodo. The position of each halo group is indicated with a locant number. The common way to name an alkyl halide is to simply name the alkyl group and then the halide (Halothane). School of Nursing Functional Groups Based on Water: Alcohol Alcohols (-OH) Have a lone pair of electrons on oxygen Functional group is the hydroxyl group, OH Since the hydroxyl group is covalently bonded to the carbon chain, alcohols do not contain a hydroxide ion. Alcohols are not strong bases. School of Nursing Functional Groups Based on Water: Alcohol Have a hydrogen atom directly bonded to an oxygen atom. Alcohols can form hydrogen bonds with other polar molecules. If the R group contains three or fewer carbon atoms, the alcohol is perfectly soluble in water. Primary (C); Secondary (CC); Tertiary (CCC) alcohols As the R group becomes larger, the solubility in water decreases. Introduction of additional hydroxyl groups increases the solubility of the compound in water. School of Nursing Aromatic alcohols are called phenols – (Ph-OH) – Not Functional Groups Based on Water: Ether Ethers (inert but highly flammable) Functional group is an oxygen bridge between two alkyl groups. The two alkyl groups may be the same or different. Often used as solvents and protecting groups that hide the much more reactive hydroxyl group of alcohols. In medical settings, ethers continue to find use as anesthetic agents. School of Nursing Functional Groups Based on Water: Ether The IUPAC rules name ethers as alkoxy alkanes. Simple ethers can also be named by citing the two alkyl groups and then adding “ether”. The most common anesthetic gases are halogenated ethers (less flammable). Halogen substitution alters blood solubility and potency. School of Nursing Amines Functional groups derived from ammonia (NH3); lone pair of electrons on the nitrogen. Nitrogen analogs of alcohols. The R can either be alkyl groups or hydrogen atoms, in any combination. Can form hydrogen bonds and tend to be more soluble in water than many other functional classes. Primary (C); Secondary (CC); Tertiary (CCC); Quaternary (CCCC) amine. School of Nursing Amines The IUPAC rule for naming amines calls for naming the alkane parent and adding “amine”. In the IUPAC system, substituent groups on a nitrogen atom are given a locant N. Probably the most important chemical reaction of amines is the basicity of amines. Most have a noticeable base strength and will accept a proton from a strong acid to form its conjugate acid (an ammonium salt) (pH controlled) Most amine medications are given as a salt since they are usually more soluble in water. School of Nursing  Carbonyl Functional Groups School of Nursing Carbonyl Functional Groups A carbonyl group is a carbon doubly bonded to an oxygen (C=O) This bonding arrangement is very strong and occurs frequently throughout the chemical world. The carbonyl carbon atom needs two more bonds to complete its octet of electrons. This group is polar. This group isn’t a functional group by itself, so… The next set of functional groups is derived by supplying various hydrogen-, carbon-, oxygen-, and nitrogen-based substituents to the carbonyl carbon. School of Nursing Aldehydes Have an alkyl group and a hydrogen atom bonded to a carbonyl group. Relatively rare among naturally occurring compounds because most aldehydes are easily oxidized to carboxylic acids, even by the oxygen in the air. Represented in medicine largely in the carbohydrates. The IUPAC rules for naming aldehydes append the suffix “al” to the parent name. The simplest aldehyde, methanal, is commonly known as formaldehyde. School of Nursing Ketones Have two alkyl groups bonded to a carbonyl group. Very common in nature and are represented in a large variety of natural compounds and medicines. The IUPAC rules for naming ketones append the suffix “one” to the parent name The simplest ketone, propanone, is commonly known as acetone. School of Nursing Reactions of Aldehydes and Ketones Oxidation and Reduction Oxidation is the loss of electrons, and reduction is the gain of electrons. Oxidation involves increasing the number of bonds to oxygen. Reduction is the opposite of oxidation. The number of bonds to oxygen decreases or the number of bonds to hydrogen increases. The oxidizing power of oxygen makes many oxidation reactions exothermic and thermodynamically favorable processes. Oxidation represents a chemical pathway School of Nursing to extract the Formation of Acetals and Ketals Alcohols are oxidized to give ketones or aldehydes. Aldehydes react with alcohols to form hemiacetals and then acetals (condensation reaction – H2O). Ketones react with alcohols to form hemiketals and then ketals (condensation reaction – H2O). Acetal/ketal formation and hydrolysis (reverse) occur under very mild chemical conditions and do not require large amounts of energy to drive either the forward process or the reverse process. School of Nursing Carboxylic Acids Functional group is the carboxyl group, which is a carbonyl group with a hydroxyl group bonded to the carbonyl carbon. Important intermediates in metabolism, and fatty acids are long- chained carboxylic acids that are principal long-term energy storage molecules. Naming carboxylic acids: append the suffix “oic acid” to the parent name. Simplest is methanoic acid, commonly known as formic acid. Next, acetic acid – Krebs cycle! One important reaction of carboxylic acids is their ability to act as acids. They are medium-strong acids, with pKa values typically between 4- 5. Conjugate bases of carboxylic acids are named by adding the suffix “oate” to the parent name. (e.g., Viagra) School of Nursing Esters Condensation products between acids and alcohols. Many have a pleasant, fruity odor. Functional group binds three fatty acid molecules to a glycerin backbone, forming a triglyceride. The portion of the ester derived from the alcohol is named as an alkyl group. The portion of the ester derived from the carboxylic acid is named as the conjugate base of that acid. School of Nursing Esters Carboxylic acids react with alcohols to form esters. To reverse that reaction back to carboxylic acid just need water, so hydrolysis reaction. In the most general sense, an ester is the condensation product between an alcohol and an acid, not just a carboxylic acid. A phosphate ester is derived from an alcohol and phosphoric acid (H3PO4). Phosphate esters form the backbone of DNA and RNA. School of Nursing Amides Condensation products between carboxylic acids and amines. Proteins are the most biologically important example of amides. The IUPAC rules name amides by appending the suffix “amide” to the parent name of the carboxylic acid from which the amide is derived. If there are substituents on the amide nitrogen, they are given the locant N. School of Nursing Amides This reaction is also a reversible process, so an amide can be torn apart by water back into a carboxylic acid and an amine. The hydrolysis of amides requires harsher reaction conditions than the hydrolysis of esters. Esters in triglycerides bind fatty acids to glycerin as an energy-dense storage molecule called a triglyceride. We need to be able to tear the triglycerides back apart to access the chemical energy stored in the fatty acids. Proteins are polymers held together by amide bonds or peptide bond. School of Nursing School of Nursing