2010 - 19th Annual NC State Undergraduate Research Spring Symposium

Session Time : 4/22/10 10:30 AM - 4/22/10 11:45 AM

Content Area : Chemistry

Student Presenters :
Amanda Lynette Patrick Chemistry

Mentors and/or Co-Authors :
Ana Ison Chemistry

Abstract Title : Organometallic Chemistry in the Undergraduate Laboratory: Preparation of Metal Carbonyl Complexes

Abstract :
The bonding of transition metals to pi acceptor ligands such as CO is a topic frequently encountered in undergraduate inorganic lecture courses. The degree of interaction between the metal and CO can be influenced by altering the other donor ligands bonded to the metal or by changing the metal itself. Changes in the CO stretch, as measured by FTIR, correlate to changes in the degree of interaction by the ligands. This experiment begins with the synthesis of a Cu carbonyl complex, Tp*Cu(CO), (Tp*= tris(3,5-dimethylpyrazolyl)hydroborate). The influence of the electron-donating ligand, Tp*, is evident as this is one of only a few stable copper carbonyl complexes currently known. The measured CO stretch of the Tp*Cu(CO) complex is 2061cm^-1 compared to the free CO stretch of 2143cm^-1. This indicates the presence of metal to CO pi* backbonding and weakening of the CO bond. Through this experiment students will learn how to synthesize, purify and characterize organometallic complexes. Fundamental concepts such as orbital bonding interactions and complex geometry will be highlighted. Future work will include the synthesis of a series of transition metal carbonyl complexes that will help demonstrate the effects on the CO stretch of varying the ancillary ligand or the metal.