Health & Environmental Research Online (HERO)


Print Feedback Export to File
8713892 
Journal Article 
Synthesis and variable-temperature1H NMR conformational analysis of Bis(η5-cyclopentadienyl)titanium pentasulfide: An experiment for an integrated, advanced laboratory course 
Diaz, A; Radzewich, C; Wicholas, M 
1995 
Yes 
Journal of Chemical Education
ISSN: 0021-9584 
72 
10 
937-938 
English 
The synthesis of (η5-C5H5)2TiS5 is well-suited for an advanced laboratory course that emphasizes the integration of synthesis and measurement. The synthesis demonstrates inert atmosphere and Schlenk techniques and has the virtue of yielding an air-stable product. The NMR measurements are done above ambient temperature without need for cooling with liquid nitrogen. The physical process, that is, the chair-to-chair conformational change of (η5-C5H5)2TiS5, can also be discussed from an energetics viewpoint, stressing the similarity with cyclohexane, a molecule undoubtedly encountered previously in organic chemistry where conformational analysis is first introduced. At this point molecular mechanics can be introduced by discussing the recent study of (η5-C5H5)2TiS5 by Lawless and Marynick (6) or by allowing students to calculate energies for various conformations (boat, chair, twist-boat, skew-boat) if a suitable computer program is available.