Transition Metals Chemistry and Coordination Compounds

A solution showing the green color of chlorophyll. The red color is the fluorescence of the molecule when irradiated with blue light. 

The model shows the chlorophyll molecule. The green sphere is the Mg ion. 

5 Bonding in Coordination Compounds Crystal Field Theory 

The series of elements in the periodic table in which the d and/subsheUs are gradually filled are called the transition elements. There are about 50 transition elements, and they have widely varying and fascinating properties. To present even one interesting feature of each transition element is beyond the scope of this book. We will therefore limit our discussion to the transition elements that have incompletely filled d subshells and to their most cottunonly encountered property—the tendency to form complex ions. 

Although the transition metals are less electropositive (or more electronegative) than the alkali and alkaline earth metals, their standard reduction potentials suggest that all of them except copper should react with strong acids such as hydrochloric acid to produce hydrogen gas. However, most transition metals are inert toward acids or react slowly with them because of a protective layer of oxide. A case in point is chromium Despite a rather negative standard reduction potential, it is quite inert 

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CHAPTER 22 TRANSITION METAL CHEMISTRY AND COORDINATION COMPOUNDS... 

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