2 resultados para Neutral Re(I) complexes
em Duke University
Resumo:
In the last two decades, the field of homogeneous gold catalysis has been
extremely active, growing at a rapid pace. Another rapidly-growing field—that of
computational chemistry—has often been applied to the investigation of various gold-
catalyzed reaction mechanisms. Unfortunately, a number of recent mechanistic studies
have utilized computational methods that have been shown to be inappropriate and
inaccurate in their description of gold chemistry. This work presents an overview of
available computational methods with a focus on the approximations and limitations
inherent in each, and offers a review of experimentally-characterized gold(I) complexes
and proposed mechanisms as compared with their computationally-modeled
counterparts. No aim is made to identify a “recommended” computational method for
investigations of gold catalysis; rather, discrepancies between experimentally and
computationally obtained values are highlighted, and the systematic errors between
different computational methods are discussed.
Resumo:
Very long-term memory for popular music was investigated. Older and younger adults listened to 20-sec excerpts of popular songs drawn from across the 20th century. The subjects gave emotionality and preference ratings and tried to name the title, artist, and year of popularity for each excerpt. They also performed a cued memory test for the lyrics. The older adults' emotionality ratings were highest for songs from their youth; they remembered more about these songs, as well. However, the stimuli failed to cue many autobiographical memories of specific events. Further analyses revealed that the older adults were less likely than the younger adults to retrieve multiple attributes of a song together (i.e., title and artist) and that there was a significant positive correlation between emotion and memory, especially for the older adults. These results have implications for research on long-term memory, as well as on the relationship between emotion and memory.