CHEM 251 1st Edition Lecture 25 Outline of Last Lecture I. Clicker QuestionII. Transition Metals Outline of Current Lecture III. Clicker QuestionsIV. NomenclatureV. Bonding and Electronic StructureVI. Spin StatesCurrent LectureVII. Clicker Questiona. Oxidation state of KMnO4i. Mn (VII)VIII. Nomenclaturea. Neutral complexes: one word — ionic complexes: two words (cation first)b. Ligands are prefixes of the metal, preceding the metal namec. Can think of as “adjectives” describing metal centerd. Neutral ligands usually keep their “free” namee. Examples: phosphine, ethylene, pyridinef. Exceptions: H2O (aquo), NH3 (ammine), CO (carbonyl)g. Anionic ligands usually receive an “-o” endingh. Examples: iodo, bromo, oxo, hydroxo, sulfido, nitratoi. Ligands placed in alphabetical orderj. Multiple same ligands are denoted by the prefixes di-, tri-, tetra-, penta-, hexa-k. Complex ligands are sometimes denoted bis-, tris-, tetrakis-l. Central metal atom identified by full name, followed by oxidation state in Roman numerals (in parentheses)m. Remember that elements are not capitalized, as in describing a rhenium complexIX. Bonding and Electronic Structurea. D-orbitals determine structureb. ExceptionsThese 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.i. Ti4+ free ion (Ti(IV) oxidation state):1. [Ar]d0: same electron configuration as K+2. Very electron deficient: wants to maximize coordination number, but all d-orbitals are available for bonding. Normally six (or more) bondsii. Au+ free ion (Au(I) oxidation state):1. [Ar]d10: completely filled sub-shell2. Not electron deficient: does not “need” ligands as badly3. In this case, 4s and 4p orbitals are frontier orbitals4. Range of coordination numbers possible, including 1!iii.iv. The energy gap, Δoct, will dictate many TM properties and reactionsv. The net energy is the same as the free ion, but a “two-over-three” patternemergesX. Spin Statesa. Spin state: high spin fills all five orbitals before pairing and low spin fills only lower orbitals before pairingb. Ions have spin S, half # of unpaired
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