ERIC Number: EJ1048345
Record Type: Journal
Publication Date: 2014-Dec
Abstractor: As Provided
Reference Count: 8
Formation of an Oxidant-Sensible Pd(II) Coordination Compound and Its [superscript 1]H NMR Specific Characterization: A Preparative and Analytical Challenge in Current Coordination Chemistry
Abraham, Maria L.; Oppel, Iris M.
Journal of Chemical Education, v91 n12 p2174-2177 Dec 2014
A three-part experiment that leads to the synthesis of palladium(II) complex starting from a C[subscript 3]-symmetric triaminoguanidinium-based ligand is presented. In the first part, the preparation of tris-benzylidenetriaminoguanidinium chloride ([H[subscript 6]Br[subscript 3]L]Cl) by an acidic catalyzed 3-fold imine formation reaction of 5-bromo-2-hydroxybenzaldehyde and triaminoguanidinium chloride is described. Starting from the second part, the reaction procedures are performed under inert gas atmosphere. The conversion of PdCl[subscript 2] with acetonitrile to give [Pd(MeCN)[subscript 4]]Cl[subscript 2] as a precursor is performed at 80 °C. The third part of the experiment is a three-step procedure that begins with deprotonation of [H[subscript 6]Br[subscript 3]L]Cl, followed by transfer of [Pd(MeCN)[subscript 4]]Cl[subscript 2] to the reaction flask, where the chelation of Pd(II)-precursor leads to the in situ species [Pd(MeCN)H[subscript 3]Br[subscript 3]L]. Addition of PPh[subscript 3] as the final reaction step yields [Pd(PPh[subscript 3])H[subscript 3]Br[subscript 3]L]. This sequence of experiments provides an excellent example of ligand and transition metal preparation and its subsequent complexation to form an oxidant-sensitive organometallic species. Undergraduate students get the opportunity to learn Schlenk techniques and to investigate [superscript 1]H NMR spectra of organic and organometallic compounds starting from relatively simple to more advanced spectra. The distinct result of the chemical shift of the [superscript 4]J[subscript P-H]-affected doublet mirrors the preparative success of the student and demonstrates the utility of [superscript 1]H NMR experiments.
Descriptors: Chemistry, Synthesis, Undergraduate Students, Interdisciplinary Approach, Inquiry, Discovery Learning, Spectroscopy, Laboratory Safety, Laboratory Experiments, Science Experiments, Teaching Methods
Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: firstname.lastname@example.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education; Postsecondary Education
Authoring Institution: N/A