CHEM 1120 1nd Edition Lecture 24 Outline of Last Lecture I Isomerism a Structural isomers i Coordination sphere ii Linkage b Stereoisomers i Geometric ii Optical Outline of Current Lecture I 5 d orbitals Octahedrals a Magnitude of d orbital splitting b Spectrochemical series c Crystal Field theory d Magnetism II D orbitals in tetrahedral fields III D orbital electronic configurations give rise to color Current Lecture I 5 d orbitals Octahedrals a Putting the electron in the orbital where there are already ligands it will take a higher energy b Splitting of energies occurs c Magnitude of d Orbital splitting i Small splitting weak field small energy difference ii Energy gap between the 2 sets of orbitals depends on the metal and the ligand iii Strong field ligands more likely to lead to a low spin complex d Spectrochemical series i Ligands can be arranged in an order based on ligand field strength This series was empirically derived using visible light absorption spectroscopy ii See power point or textbook to see the series e Crystal Field Theory i Energy gap between d orbitals often corresponds to the energy in a photon of visible light 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 f II III Magnetism i Number of unpaired electrons determines whether the complex is paramagnetic or diamagnetic g Ligand effect on splitting energy i Since ligands affect whether a complex is high or low spin ligands affect of unpaired electrons ii Since more unpaired electrons correlates to a greater magnetic moment ligands have dramatic effects on magnetic properties h Ligand field stabilization energy gained by putting electrons in lower energy orbitals i Complexes which undergo rapid ligand exchange are labile slow inert D Orbitals in tetrahedral fields a No change for square planar complexes D orbital electronic transitions give rise to color a Colors come from impurities b Move an electron to a higher energy c Metal complex can absorb a particular wavelength of light which leads to an excitation of an electron from one orbital d Calculating the energy gap E hc wavelength e Sample is irridated by light of various wavelengths absorption spectroscopy f Each set of ligands results in a slightly different d orbital splitting with different wavelength color of light absorbed g Use color wheel Is yellow light is absorbed solution is purple
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