Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Physical Sciences and Mathematics
Cacao Use And The San Lorenzo Olmec, Terry G. Powis, Ann Cyphers, Nilesh W. Gaikwad, Louis Grivetti, Kong Cheong
Cacao Use And The San Lorenzo Olmec, Terry G. Powis, Ann Cyphers, Nilesh W. Gaikwad, Louis Grivetti, Kong Cheong
Faculty and Research Publications
Mesoamerican peoples had a long history of cacao use—spanning more than 34 centuries—as confirmed by previous identification of cacao residues on archaeological pottery from Paso de la Amada on the Pacific Coast and the Olmec site of El Manatí on the Gulf Coast. Until now, comparable evidence from San Lorenzo, the premier Olmec capital, was lacking. The present study of theobromine residues confirms the continuous presence and use of cacao products at San Lorenzo between 1800 and 1000 BCE, and documents assorted vessels forms used in its preparation and consumption. One elite context reveals cacao use as part of a …
A Bis-Urea Naphthalene Macrocycle Displaying Two Crystal Structures With Parallel Ureas, Michael F. Geer, Mark D. Smith, Linda S. Shimizu
A Bis-Urea Naphthalene Macrocycle Displaying Two Crystal Structures With Parallel Ureas, Michael F. Geer, Mark D. Smith, Linda S. Shimizu
Faculty Publications
Herein we synthesized a bis-urea macrocycle from 2,7-dimethylnaphthalene that displays an unusual parallel urea conformation. The naphthalenes also adopt a bowl shape over the anticipated parallel planar orientation. Crystallization of the macrocycle from different solvent systems affords two solvated forms. 1·DMSO·(H2O)2 has an extended columnar structure where parallel macrocycles are linked by intervening hydrogen bonded water molecules. In 1·(MeOH)2direct hydrogen-bonds link the macrocycles into chains, which hydrogen-bond with methanolmolecules to form a layered structure.