Structural study of new hydrocarbon nano-crystals by energy-filtered electron diffraction.

Ultramicroscopy

PubMedID: 15046793

Wu JS, Melcer N, Sharp WP, O'Keeffe M, Spence JC, Yaghi OM. Structural study of new hydrocarbon nano-crystals by energy-filtered electron diffraction. Ultramicroscopy. 2004;98(2-4):145-50.
A new brittle hydrocarbon has been successfully synthesized in polycrystalline form, and its crystal structure solved by quantitative electron diffraction. By 3D tilting of the nano-crystals, the lattice type and unit cell parameters were determined. (Triclinic, [Formula: see text] A, [Formula: see text] A, [Formula: see text] A, [Formula: see text] degrees, [Formula: see text] degrees, and [Formula: see text] degrees.) Spot diffraction patterns were obtained at -165 degrees C using the Koehler selected-area mode on a LEO 912 TEM fitted with an omega in-column elastic energy filter. The direct methods algorithm was then applied to merged intensities and a trial structure obtained assuming single scattering. This was further refined to obtain good agreement with a small residual of about 10% using multiple scattering calculations. A diagram of the proposed structure is given.