| Four anthracene-based ligands were synthesized bearing thiaazaalkanes at the 9 position, which were linked through either a methylene or a carbonyl bridge. Titrations of these ligands with AgSbF6 in 70:30 CH 2Cl2:EtOH solution showed that Ag(I) binding affinities decreased as the number of Lewis base donor atoms decreased. Specifically, the Ag(I) affinities were: 6-(9'-anthrylmethyl)-3,9-dithia-6-azaundecane (NS 2Anthramine), 1 x 107 M -1 > 6-(9'-anthrylmethyl)-3-thia-6-azaoctane (NSAnthramine ), 1 x 105 M-1 > 6-(9'-anthracenecarbonyl)-3,9-dithia-6-azaundecane (NS2Anthramide), 1 x 103 M -1 > 6-(9'-anthracenecarbonyl)-3-thia-6-azaoctane (NSAnthramide ), ∼1 x 101 M-1. Ligands with amine-based ionophores, NS2Anthramine and NSAnthramine, exhibited changes in the absorbance and emission spectra related to binding between Ag(I) and the N lone pair. These changes included a 7-nm bathochromic shift for all absorbance bands upon addition of 1 equiv Ag(I), and an increase in emission intensity due to the relief of photoinduced electron transfer from the amine to the anthracene. Ag(I)-bound NS 2Anthramide experienced a decrease in emission intensity due to heavy atom quenching, while NSAnthramide did not bind Ag(I). The Ag(I)-bound ligands that retained an open coordination site, NS 2Anthramide and NSAnthramine, exhibited increased emission intensity upon exposure to C2H4.;The Institute for Chemical Education (ICE) developed two new themed camps in 2004 and 2005. "Fun with Forensic Science" was beta-tested by ten sites nationwide in 2005 and "Fun with Chemistry Inventions" was revised locally at the University of Wisconsin-Madison over a period of two years. In addition to offering new camp experiences, ICE conducted research on its middle school-aged camp participants in 2006 and 2007. In both years, campers' attitudes towards science were measured and compared pre-/post-camp using five of the seven scales from the Test of Science-Related Attitudes (TOSRA). In 2007, ICE also introduced a pedagogy-focused training program for undergraduate student group leaders and assessed how the level of pedagogical chemical knowledge (PChK) of group leaders (GLs) affected changes in their campers' attitudes toward science and scientists. Participation in the training program led to GLs demonstrating higher levels of PChK than their peers (p<0.05). Though some changes in campers' attitudes were observed after the week-long camp intervention, no consistent trends emerged among the results. |
