Introduction to Pharmaceutical Inorganic Chemistry

Opening Prayer

• Dear Lord, Teach me the things that are important:

• To be generous with Your gifts,

• Compassionate to those who have less,

• Just in the face of unfair circumstances,

• True when the world's values contradict my own,

• Gracious when things don't go my way,

• And magnanimous when they do.

• May nothing else matter Except Faith in Your goodness, my neighbor's, and mine,

• Hope that things can get better,

• And Charity that always sets things right.

• May Your special Love for the Poor, The mark of my uniquely Vincentian education,

• Be the work I excel in, The standard I constantly refer to, And my courage when I meet You someday.

• O Mary conceived without sin, Pray for us who have recourse to thee. St. Vincent de Paul, Pray for us.

Fundamental Concepts and the Periodic Table

• Definition of an Element: A substance that cannot be separated into simpler substances by chemical means.

• The Periodic Table of Elements: A map of the building blocks of matter. It serves as a definitive classification of all known chemical elements.

• Reading the Periodic Table: Each entry contains the Atomic Number, Boiling Point (in ${}^{\circ}C$), Symbol, Name, and Atomic Mass.

• State of Matter at Room Temperature: Metals are solid, except for mercury ($Hg$). Nonmetals can be solid, liquid, or gas at room temperature.

Etymology and Derivations of Element Symbols

• Antimony ($Sb$): Derived from the Latin Stibium, meaning "mark."

• Copper ($Cu$): Derived from Cuprum, from Cyprium (Latin name for the island of Cyprus, a major source of copper in the Roman Empire).

• Gold ($Au$): Derived from the Latin Aurum, meaning "gold."

• Iron ($Fe$): Derived from the Latin Ferrum, meaning "iron."

• Lead ($Pb$): Derived from the Latin Plumbum, meaning "heavy."

• Mercury ($Hg$): Derived from the Latin Hydrargyrum, meaning "liquid silver."

• Potassium ($K$): Derived from Kalium, from the Arabic al-qili, meaning "alkali."

• Silver ($Ag$): Derived from the Latin Argentum, meaning "silver."

• Sodium ($Na$): Derived from the Latin Natrium, meaning "sodium."

• Tin ($Sn$): Derived from the Latin Stannum, meaning "tin."

• Tungsten ($W$): Derived from Wolfram, German for "wolf stone," so named because it interfered with tin smelting and was thought to "devour" the tin.

Classification of Elements by Group and Block

• Group Designations:

  • Group IA: Alkali Metals.

  • Group IIA: Alkaline Earth Metals.

  • Group IIIA: Boron Group.

  • Group IVA: Carbon Group.

  • Group VA: Nitrogen Group.

  • Group VIA: Oxygen Group.

  • Group VIIA: Halogens.

  • Group VIIIA: Noble Gases.

  • Group IB: Coinage Metals.

• Representative Elements: Elements with incomplete $s$ and $p$ orbitals.

• Transition Elements: Elements with $d$ orbitals being completed.

• Inner Transition Elements: Elements with $f$ orbitals being completed.

• Orbital Blocks:

  • s-block: Groups 1A and 2A.

  • p-block: Groups 3A to 8A.

  • d-block: Transition elements (Groups 1B and 3B-8B).

  • f-block: Inner-transition elements (Lanthanide and Actinide series).

Properties and Characteristics of Element Families

• Hydrogen: Belongs to a family of its own. It is a diatomic, reactive gas. It was involved in the Hindenburg explosion and is considered a promising alternative fuel for automobiles.

• Alkali Metals (Group 1): The first column (excluding Hydrogen). These are very reactive metals, soft enough to cut with a butter knife, and always found in nature combined with other elements (e.g., in salt).

• Alkaline Earth Metals (Group 2): Reactive metals always combined with nonmetals in nature. Important mineral nutrients include Magnesium ($Mg$) and Calcium ($Ca$).

• Transition Metals (Groups 3-11): Less reactive than alkali/alkaline earth metals; they are harder metals used in construction, jewelry, and are used "as metal."

• Boron Family (Group 13): Aluminum is a member; it was once extremely rare and expensive.

• Carbon Family (Group 14): Contains elements vital for life and computers. Carbon is the basis of an entire branch of chemistry; Silicon ($Si$) and Germanium ($Ge$) are critical semiconductors.

• Nitrogen Family (Group 15): Nitrogen makes up more than $3/4$ of the atmosphere. Nitrogen and Phosphorus ($P$) are essential for living things. The red coating on match tips is phosphorus.

• Oxygen Family (Group 16): Oxygen is necessary for respiration. Sulfur ($S$) is known for its distinctive odor in rotten eggs, garlic, and skunk spray.

• Halogens (Group 17): Very reactive, volatile, diatomic nonmetals. Used as disinfectants and to strengthen teeth; they are always found combined in nature.

• Noble Gases (Group 18): Extremely unreactive, monatomic gases with full valence shells. Used in lighted signs (neon).

Historical Evolution of the Periodic Table

• Antoine Lavoisier: Created the first extensive list of elements, identifying approximately 33. He classified them into Metals vs. Non-Metals.

• Johann Wolfgang Döbereiner: Formulated Dobereiner’s Triads. Elements were arranged in groups of 3 with similar properties, where the middle element's properties were halfway between the other two.

• John Alexander Reina Newlands: Created the Law of Octaves, stating any given element exhibits analogous behavior to the eighth element following it.

• Dmitri Ivanovich Mendeleev: Published the first table arranged by atomic weight and families. He asserted that properties are in periodic dependence on atomic weight. He predicted unknown elements.

• Henry Moseley: Arranged elements by increasing atomic number. He demonstrated a periodic pattern in chemical and physical properties when ordered by atomic number. He assigned atomic numbers to elements.

Mendeleev’s Predicted Elements (Sanskrit Names)

• Eka-aluminium: Modern name Gallium.

• Eka-boron: Modern name Scandium.

• Eka-silicon: Modern name Germanium.

• Eka-manganese: Modern name Technetium.

• Tri-manganese: Modern name Rhenium.

• Dvi-tellurium: Modern name Polonium.

• Dvi-caesium: Modern name Francium.

• Eka-tantalum: Modern name Protactinium.

Comparison of Mendeleev’s Predictions vs. Observed Data

• Eka-aluminium vs. Gallium:

  • Predicted Atomic Weight: $68$; Observed: $70$.

  • Predicted Density ($g/cm^3$): $5.9$; Observed: $5.94$.

  • Predicted Melting Point: Low; Observed: $29.78^{\circ}C$.

  • Formula of Oxide: $E_2O_3$; Observed: $Ga_2O_3$.

• Eka-silicon vs. Germanium:

  • Predicted Atomic Weight: $72$; Observed: $72.59$.

  • Predicted Density ($g/cm^3$): $5.5$; Observed: $5.35$.

  • Predicted Melting Point: High; Observed: $947^{\circ}C$.

  • Formula of Oxide: $EO_2$; Observed: $GeO_2$.

Atomic Structure and Nuclei

• Atomic Components:

  • Protons: Positively charged; attract electrons due to opposite charge.

  • Neutrons: Neutral charge; affect the weight of the atom, not its chemical properties.

  • Electrons: Negatively charged particles found in a cloud around the nucleus.

• Nucleus: Positively charged, extremely dense region consisting of protons and neutrons, sized at approximately $10^{-15}\,m$.

• Electron Cloud: Sized at approximately $10^{-10}\,m$.

• Atoms and Charges:

  • Electrically neutral atom: Number of protons equals number of electrons.

  • Atomic Number ($p$): Number of protons (also number of electrons in a neutral atom).

  • Atomic Mass ($n$): Sum of protons and neutrons.

• Isotopes of Hydrogen:

  • Hydrogen (Protium): 1 proton, 0 neutrons (Atomic Mass 1).

  • Deuterium: 1 proton, 1 neutron (Atomic Mass 2).

  • Tritium: 1 proton, 2 neutrons (Atomic Mass 3).

Key Figures in Atomic Theory

• Democritus: Coined the term "atomos."

• John Dalton: Proposed the Billiard Ball Model.

• J.J. Thompson: Discovered electrons.

• Rutherford: Identified alpha and beta particles.

• Chadwick: Discovered neutrons.

• Goldstein: Discovered protons.

• R. Millikan: Determined the charge of electrons.

• Faraday: Developed the cathode ray tube.

• Roentgen: Discovered X-rays.

• Bequerel: Discovered radioactivity.

• P. Villard: Discovered gamma radiation.

• Neils Bohr: Proposed the "shell model."

• Heisenberg: Formulated the Uncertainty Principle.

• Schrodinger: Associated with quanta.

• Kekule: Defined valency.

• De Chancourtois: Proposed the periodicity of elements.

Periodic Table Trends

• Ionization Energy: The amount of energy required to remove an electron from an atom. It measures how strongly the atom holds its electron.

  • Top to Bottom: Decreases.

  • Left to Right: Increases (with exceptions from 2A to 3A and 5A to 6A which decrease).

• Electron Affinity: The ability to accept one or more electrons. It measures how strongly atoms attract additional electrons.

  • Top to Bottom: Decreases.

  • Left to Right: Increases.

• Electronegativity: The ability of an atom in a molecule to attract electrons to itself to form a covalent bond.

  • Top to Bottom: Decreases.

  • Left to Right: Increases.

• Atomic Size (Radius):

  • Top to Bottom: Increases.

  • Left to Right: Decreases.

• Metallic and Non-Metallic Character:

  • Metallic character increases Top to Bottom and decreases Left to Right.

Ions and Redox

• Ions: Electrically charged atoms formed by the gain or loss of electrons through redox (reduction-oxidation) processes.

  • Cation: Positive ion created by electron loss.

  • Anion: Negative ion created by electron gain.

Binary Compound Nomenclature

• Definition: Binary compounds consist of only two elements.

• Compounds of 2 Non-Metals: Name the less electronegative element first, followed by the more electronegative element with the suffix "-ide."

  • Greek prefixes (mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca) specify the number of atoms.

  • "Mono-" is not used for the first element.

  • Examples: $N_2O$ (dinitrogen monoxide), $CO_2$ (carbon dioxide), $PBr_5$ (phosphorus pentabromide).

• Acids (Hydrogen + Non-Metal): The prefix "hydro-" is added to the non-metal stem, and the "-ide" ending is replaced with "-ic acid."

  • Example: $HCl_{(aq)}$ is hydrochloric acid; $H_2S_{(aq)}$ is hydrosulfuric acid.

• Salts (Metal + Non-Metal): Name of the metal + name of the non-metal with the suffix "-ide."

  • Example: $NaCl$ (sodium chloride), $Mg_3N_2$ (magnesium nitride).

• Variable Valence Metals (Multiple Oxidation States):

  • Stock Method: Name the metal + Roman numeral in parenthesis indicating oxidation state + non-metal with "-ide." Example: $FeCl_2$ is iron(II) chloride.

  • Classical Method: Uses suffixes "-ous" for the lower oxidation state and "-ic" for the higher oxidation state attached to the Latin root. Example: $FeCl_2$ is ferrous chloride; $FeCl_3$ is ferric chloride.

Ternary Compound Nomenclature

• Definition: Compounds consisting of three different elements, where the third is usually Oxygen.

• Ternary Acids (Oxy-Acids):

  • Rule: More oxygen atoms = "-ic"; fewer oxygen atoms = "-ous."

  • Extended Series: "per-…-ic" (one additional oxygen); "hypo-…-ous" (one less oxygen).

  • Ion Correlation: "-ous acid" forms "-ite" salt; "-ic acid" forms "-ate" salt.

  • Example: $HClO_4$ (perchloric acid), $HClO_3$ (chloric acid), $HClO_2$ (chlorous acid), $HClO$ (hypochlorous acid).

• Bases: Named as hydroxides. Example: $NaOH$ (sodium hydroxide), $Fe(OH)_3$ (ferric hydroxide).

• Ternary Salts (Salts of Oxy-Acids): retain acid prefixes, but change suffixes ("-ite" or "-ate").

  • Example: $NaNO_3$ (sodium nitrate), $NaNO_2$ (sodium nitrite).

Specialized Salt Classifications

• Acid Salts: Salts of polyprotic acids where one or more hydrogen atoms remain. Named by adding "hydrogen" or the prefix "bi-" to the oxyanion name.

  • Example: $NaHCO_3$ (sodium hydrogen carbonate or sodium bicarbonate).

• Basic Salts: Contain oxide ion ($O^{2-}$) or hydroxide ($OH^{-1}$) along with another anion.

  • Example: $BiOCl$ (Bismuth subchloride/oxychloride), $Co(OH)NO_3$.

• Mixed and Double Salts: Salts containing two cations. The cation with the lower charge is named first. Greek prefixes indicate atom counts.

  • Example: $KCaPO_4$, $Na_2Ca(SO_4)_2$.

Miscellaneous Inorganic Syllables

• iso-: Indicates an isometric form (e.g., isocyanic acid $HNCO$ vs cyanic acid $HOCN$).

• meta-: Indicates a low hydrated form resulting from the removal of 1 molecule of $H_2O$ from 1 molecule of an ortho-acid (e.g., metaphosphoric acid $HPO_3$).

• ortho-: Indicates the highest stable hydrated form of an oxy-acid (e.g., orthophosphoric acid $H_3PO_4$).

• pyro-: Indicates loss of water from 2 molecules of an ortho-acid (e.g., pyrophosphoric acid $H_4P_2O_7 = 2 H_3PO_4 - H_2O$).

Coordination Compounds

• Definition: Compounds containing coordinate covalent bonds formed between metal ions (Lewis acid) and groups of anions or polar molecules (Lewis base/Ligands).

• Complex Ion: An ion in which a metal cation is covalently bound to one or more molecules or ions, enclosed in square brackets $[ \dots ]$.

• Ligands: Molecules or ions surrounding the metal. They must contain at least one unshared pair of valence electrons.

• Coordination Number: The number of donor atoms surrounding the central metal atom (commonly 4 or 6).

• Ligand Classifications:

  • Monodentate: 1 donor atom.

  • Bidentate: 2 donor atoms (e.g., Ethylenediamine "en", Oxalate ion).

  • Polydentate: More than 2 donor atoms (e.g., EDTA).

  • Chelating Agents: Another term for bidentate or polydentate ligands.

Nomenclature of Coordination Compounds

• Order: The cation is named before the anion.

• Complex Ion Internal Naming: Ligands are named first in alphabetical order, followed by the metal ion.

• Ligand Endings: Anionic ligands end in "-o." Neutral ligands use molecule names (exceptions: $H_2O$ is aquo, $CO$ is carbonyl, $NH_3$ is ammine).

• Quantity Prefixes: Greek prefixes specify ligand count. If the ligand name already contains a Greek prefix, use bis- (2), tris- (3), tetrakis- (4).

• Metal Names: If the complex is an anion, the metal name ends in "-ate."

  • Iron becomes Ferrate.

  • Copper becomes Cuprate.

  • Lead becomes Plumbate.

  • Silver becomes Argentate.

  • Gold becomes Aurate.

  • Tin becomes Stannate.

• Oxidation State: Indicated by Roman numerals in parentheses immediately after the metal name.

• Naming Example: $[Cr(H_2O)_4Cl_2]Cl$ is named Tetraaquodichlorochromium(III) chloride.

• Formula Writing Example: tris(ethylenediamine)cobalt(III) sulfate is written as $[Co(en)_3]_2(SO_4)_3$.