Chem 1120 1st Edition Lecture 22Outline of Last Lecture I. Other Group 6A ElementsII. Nitrogen FamilyIII. Allotropes/Carbon Family/Boron FamilyOutline of Current Lecture I. Transition Metal Properties and TrendsII. MagnetismIII. Coordination Complexes and LigandsCurrent Lecture I. Most metals, including transition metals,are found in solid inorganic compoundsknown as minerals, minerals are named bycommon, not chemical, namesPartially filled d orbitals —> multipleoxidation states, -3 to +8s orbitals are filled first (except Cr, Cu)Unpaired electrons —> paramagnetic —>magnetic propertiesColors from electron transitions between dorbitalsCoordination compounds with 4-9 ligandsMost transition metal ions = colorful and paramagnetic (except those with d10configuration)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Atomic Radii: trends in atomic radii are similar across all three rows of transition metals, while effective nuclear charge increases across a row, so does the number of nonbonding electrons, therefore these repel each other and increase the radius, also metallic bonding strength increases to middle and then decreases as anti-bonding orbitals are filledThese effects work together to decrease and counteract to lead to increaseGeneral trend = Bonds shorten as they become strongerAtomic size remains fairly constant as atomic number increases/you go across the periodic table because electrons are added to inner shells, shielding outer electrons from nuclear charge efficiency II. Magnetism can be used to analyze d electron populationsThree major types of magnetic behavior: Diamagnetic = no atoms or ions with magnetic momentsParamagnetic = magnetic moments unaligned without a magnetic fieldFerromagnetic = coupled magnetic centers aligned in common direction without magnetic field Ferrimagnetism:Ferrimagnetic substances have spins that align opposite each other, but the spins are not equal, so there is a net magnetic fieldThis can occur because —> magnetic centers have different numbers of unpaired electrons, and more sites align in one direction than the otherAntiferromagnetism:Antiferromagnetic substances have unpaired spins on adjacent atoms that align in opposing directions, these magnetic fields tend to cancel each other III. Commonly, transition metals can have molecules or ions that bond to them, these give rise to complex ions or coordination compoundsThe molecules or ions that bind to the central metal are called ligands, molecules and/or anions with one or more donor atoms that each donate a lone pair of electrons to the metal ion to form a covalent bondMonodentate ligands coordinate to one site on the metal, bidentate to two, and polydentate to more than two (bi- and poly- dentate ligands are also called chelating agents)Coordination complexes: compounds formed by Lewis acid-base interactions,a coordinate covalent bond, transition metals or their ions are Lewis acids and ligands are Lewis basesComplexes: metal atom or ion bonded to by ligands, complexes do not dissociate into ions, they act as a single molecule or ion, lots of different colored complexesSquare brackets enclose the complex ion, while counterions are outside the bracketsNumber of ligands bound to metal = coordination number Metal atom + the ligands bound to it = coordination