J. V. Smith and W. L. Brown. Feldspar Minerals: 1. Crystal Structures, Physical, Chemical, and Microtextural Properties. 2nd Edition. Berlin, Heidelberg and New York (Springer-Verlag), 1988. xviii + 828 pp., 352 figs. Price DM360.00.

1989 ◽  
Vol 53 (373) ◽  
pp. 655-656
Author(s):  
W. S. MacKenzie
2001 ◽  
Vol 57 (6) ◽  
pp. 780-790 ◽  
Author(s):  
Dirk J. A. De Ridder ◽  
Kees Goubitz ◽  
Margot Fontijn ◽  
Pavla Čapková ◽  
Eva Dova ◽  
...  

The crystal structures of potassium [2.2]paracyclophane-4-sulfonate (1), [2.2]paracyclophane-4,15-disulfonic anhydride (2), [2.2]paracyclophane-4,15-disulfonimide (3), N-n-propyl-[2.2]paracyclophane-4,15-disulfonimide (4), N-isopropyl-[2.2]paracyclophane-4,15-disulfonimide (5), N-cyclopropyl-[2.2]paracyclophane-4,15-disulfonimide (6) and N-phenyl-[2.2]paracyclophane-4,15-disulfonimide (7) were established by single-crystal X-ray diffraction. The structural changes caused by sulfonation are discussed with respect to the parent [2.2]paracyclophane (tricyclo[8.2.2.24,7]hexadeca-4,6,10,12,13,15-hexaene). The main features are a change in the non-bonding distances between the para-phenylene rings and a rotation of these rings with respect to the molecular symmetry plane. The rings are rotated away from each other in the case of monosulfonation (1), but are rotated in the opposite way in the case of the disulfonic anhydride (2) or the disulfonimide compounds (3)–(7). The results are also discussed in terms of the parameters proposed by Keehn [(1983), Organic Chemistry, A Series of Monographs 45, edited by P. H. Keehn & S. M. Rosenfeld, Vol. 1, pp. 69–238. New York: Academic Press] showing that (bonded and non-bonded) angles involving the para-phenylene rings are mainly affected.


Author(s):  
Konstadina Dalacosta ◽  
Evangelia. A. Pavlatou

In chemical engineering, undergraduate students often have to face the highly demanding process of understanding concepts from the microscopic level (e.g., ionic crystals such as zinc sulphide or covalent lattice crystals diamond, graphite, graphene etc.) and then explain with certain physical–chemical properties their macroscopic behaviour. Therefore, the main idea was to construct a specifically designed educational material that focusses on the benefits of viewing visualisations to enhance students’ conceptual understanding of solids and crystal structures augmented by cartoons, and evaluate its usability. The interactive ‘cartoons’ agents were developed from scratch, giving them freedom of movement and realism at the same time. A research was conducted in the School of Chemical Engineering in Greece (National Technical University of Athens), evaluated the usability of the digital material and the contribution of the 3-D visualisations and the cartoons agents in the understanding of such high-cognitive load concepts.Keywords: Cartoons, 3-D visualisations, crystal structures, chemical engineering.


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