In the system Ag-In, the isothermal phase transformation at 281 "C previously assumed by Weibke and Eggers has been found not to exist. Metastability of they phase and of the indium phase is persistent at room temperature. The boundaries of the intermediate phases have been redetermined. At room temperature, the equilibrium y phase (hexagonal) exists between 71.0 and 70.3 % silver. At 325 "C and higher temperatures, the y-phase region extends to higher indium concentrations than those given by Weibke and Eggers. The order-disorder transforn~ation of the y phase, postulated by Hellner, does not appear to exist. The liquidus is found to lie approximately 8 "C higher than that determined by Weibke and Eggers.At room temperature, the E phase exists between 67.5 and 65.0% silver. At these compositions, the cubic cell edges of the E phase are o = 9.878 + 0.004 and 9.887 0.004 A, respectively. The y/(y + E) phase boundary has been redetermined and extended.A new a' phase is claimed to exist at approximately 73.8 wt. % silver. It is formed by a peritectoid phase reaction at 187". In the a' phase the silver atoms occupy the face-centered positions and the indium atoms, the corner positions of the cubic lattice. The intensities of diffraction lines were calculated using such a model and were found to be in reasonable agreement with the observed intensities of the a' phase. The cell edge of the a' phase is 4.144 + 0.004 A, at room temperature, and this is identical, within experimental error, with that of the a phase.A new phase diagram for the Ag-In system has been constructed.
H N M R spectroscopic studies established the presence of a chair conformation for endu-3-methyl-6-morpholino-3-azabicyclo[3.1 .O] hexane derivatives 8a and b. This was additionally confirmed b y an X-ray structural analysis of 8b. The diastereomers 1 Oa,b and the N-demethyl-endo-morpholino compounds 9a,b, however, were found t o prefer a boat conformation. The correlation between dihedral angles and ring buckle of 3-azabicyclo[3.1 .O]hexane 4 was determined b y MNDOC semiempirical calculations. Further structural information about this bicyclic system was obtained b y HF/6-31 G * calculations for the 3-azabicyclo[3.1 .O] hexane parent compounds 4 and 5 . X-Ray structural analyses of some 3-azoniabicyclohexane derivatives 1,' 2l and 32 showed that this type of compound adopts mainly a boat conformation in the solid state. 3-Azoniabicyclo[3.1 .O] hexane derivatives 63 and 7,4 however, possessing two additional substituents at the N(3)-atom, prefer a chair conformation as the most favourable structure.RN
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.