Structure 3.1

• Formal charge (of any element with values connected to that element only)

  # of valance electrons - (# of bonds + # of non-bonded electrons)
• Biodegradable materials

  Made of naturally occurring monomers (ex. castor oil, dextrose, sucrose) that are not derived from fossil fuels (ex. Alkenes).
• Electron promotions in color complexes

  Bonding of ligands to central transitional metals split d-sub levels into high and low energies as the ligands lone pair repel the transition metal's electrons. Electrons absorb white light energy and are promoted to a higher level.
• Crystal Field theory

  Properties of complex ions are caused by the splitting of d-orbitals into two different energies: 2 of higher energy, and 3 of lower energy
• Why are metal complexes colored?

  Electron absorbing white light will absorb certain colors of light and emit other to be promoted to a higher energy level. The color that they've absorbed is complimentary to the color they've absorbed (ex. Red is the color of the solution so green light was absorbed)

  
• Ligands 


  Molecules or ions with at least one lone pair of electrons that attach themselves to metal ions with high positive charges (ex. transitional metals). Like; H2O, NH3, CN^-, OH^-, C2H4^(2-)
• How to write a complex ion

  [] used to encase the equation to show its complexity

  charge outside the bracket corresponding to metal's charge

  () inside [] and beside the metal to contain the equation of the ligand

  a subscript below the () to show how many ligands are used and also that they are surrounding the metal
• IUPAC naming

  Official organic chemistry nomenclature recommended by the International Union of Pure and Applied Sciences
• Melting point

  Decreases with greater atomic weight as there are more energy levels, meaning the electrons are farther away from the nucleus and easier to ionize and change
• Color complexes

  Must be from a transition metal

  Must have split d-sub levels

  --> These must be only partially filled with at least 1 remaining empty

  or singly filled

  Electrons must be promoted up with absorbtion
• Chirality

  Carbon bonded to four different groups creates a chiral center around which optical activity is present in the molecule
• Boron, Beryllium, and Hydrogen

  Stable without 8 valance electrons
• Molecules are not charge

  They, therefore, do not conduct heat or electricity
• Oxidation states for Group 4 elements

  They are not specified as they have a low tendency to form ions
• Metalloids

  Are in between metals and non-metals, showing intermediate characteristics of both. Include Boron (B), Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), Tellurium (Te), Polonium (Po), Astatine (Ab)
• Ionization energies


  Is easier observed in gases as comparison between elements in gas state are able to isolated and simply looked at as 1 molecule of gas which cannot be done with solids or liquids. Additionally, gas particles have very low attraction to each other, so there is little external attraction that could affect ionization
• Dips in ionization

  Occur when shielding is higher (there are more inner electrons exposed than valance) or when removing pairs from an orbital that is already repelling each other and hence, easier to remove
• The first ever periodic table

  Created by Dmitri Mendeleev in 1869 and arranged according to mass instead of atomic number due to ignorance to the presence of isotopes of an element.
• Metallic bonds in transitional metals

  Have melting points that are generally very high, with great hardness due to their greater electron density and better electrical conductivity due to the electrons in their d-sub level that are not filled (copper most conductive)
• Zinc

  Is not considered a transition metal
• Sc is a transition metal without multiple oxidation states hence it can't form colored complexes
• ionic compounds want to disassociate into ions- they do not want to break water hydrogen bonds.
• covalent compounds prefer to form bonds so can break hydrogen bonds
• ligand is a molecule or ion that can bond to a central metal ion to form a complex by donating an electron pair that forms a coordinate bond
• colored complexes are formed in the presence of unpaired electrons as d-orbitals are split, allowing electrons to move between energy levels and emits/absorb energy at a visible wavelenght