Page 164 - Materials Chemistry, Second Edition

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References
55
See Shriver et al. Inorganic Chemistry, 4th ed., W. H. Freeman: New York, 2006 for more details re
LMCT and MLCT processes.
56
For more information regarding the trichroism of iolite and its use as a “Viking compass”, see: http://
www.nordskip.com/iolite.html
57
Note: the Pauli exclusion principle states that each electron must possess a different set of four
quantum numbers; that is, two electrons housed in the same orbital (identical n, l, m l ) must be of
opposite spin (m s ¼ 1/2).
58
Note: the work function is the solid-state analogy of ionization energy, defined as removing the
outermost electron from a gaseous atom. In general, the work function is ca. 1/2 the value of the
ionization energy of its corresponding gaseous atoms.
59
(a) Reif, F. Fundamentals of Statistical and Thermal Physics. McGraw–Hill: New York, 1965.
(b) Blakemore, J. S. Semiconductor Statistics. Dover: Canada, 2002.
60
Note: for AC current, the velocity would be identical to DC, but the electrons would travel back/forth,
resulting in a much smaller drift velocity. A nice explanation of the speed of electricity may be found
online at: http://www.radioelectronicschool.net/files/downloads/howfast.pdf
61
Kittel, C. Introduction to Solid State Physics, 8th ed., Wiley: New York, 2004.
62
For a recent review, see Cheetham, A. K.; Mellot, C. F. Chem. Mater. 1997, 9, 2269. It should be noted
that the hydrolytic condensation of trifunctional organosilicon monomers (e.g., RSiCl 3 or RSi(OMe) 3 )
results in polyhedral oligomeric silsesquioxanes (POSS) – see: http://www.azonano.com/details.asp?
ArticleID¼1342#_POSSTM_Polymers_Polymerization/Gr. These structures represent the smallest
forms of silica, often being denoted as “molecular silica”. Since particle diameters range from 0.07
to 3 nm, these are important architectures for nanoapplications (e.g., see http://www.reade.com/
Products/Polymeric/poss.html
63
Note: a supercritical fluid has intermediate properties of liquid and gas. Typically, the alcogel is placed
in an autoclave filled with ethanol. The system is pressurized to 750–850 psi with CO 2 and cooled to

5–10 C. Liquid CO 2 is then flushed through the vessel until all the ethanol has been removed from the
vessel and from within the gels. When the gels are ethanol-free, the vessel is heated to a temperature
above the critical temperature of CO 2 (31 C). As the vessel is heated, the pressure of the system rises.

The pressure of CO 2 is carefully monitored to maintain a pressure slightly above the critical pressure
of CO 2 (1050 psi). The system is held at these conditions for a short time, followed by the slow,
controlled release of CO 2 to ambient pressure. The length of time required for this process is
dependent on the thickness of the gels; this process may last anywhere from 12 h to 6 days.
64
For a recent review on the synthesis, properties, and applications of aerogels see: Pierre, A. C.; Pajonk,
G. M. “Chemistry of Aerogels and Their Applications”, Chem. Rev. 2002, 102, 4243.
65
Note: the g-Al 2 O 3 crystal structure is best described as a defect spinel structure comprised of a
2 2 2 fcc array of oxide ions with 21/3 aluminum ions divided over the octahedral and tetrahedral
interstices. By contrast, a-Al 2 O 3 is an HCP array of O , with Al 3þ in 2/3 of the octahedral sites. For
2
thermal transformations of alumina, see: Stumpf, H. C.; Russell, A. S.; Newsome, J. W.; Tucker, C. M.
Ind. Eng. Chem. 1950, 42, 1398.
66
For a comprehensive database of zeolite structures refer to: http://www.iza-structure.org/databases/
67
For a recent review of applications for zeolite thin films, see: Lew, C. M.; Cai, R.; Yan, Y. Acc. Chem.
Res. 2009, ASAP.
68
For comprehensive building models for zeolite frameworks, see: http://www.iza-structure.org/data-
bases/ModelBuilding/Introduction.pdf
69
For a review of applications for mesoporous zeolites, see: Corma, A. Chem. Rev. 1997, 97, 2373.
70
For a comprehensive review of hydrothermal methods used to synthesize zeolites, see: Cundy, C. S.;
Cox, P. A. Chem. Rev. 2003, 103, 663. A laboratory protocol for the synthesis and characterization of
the ZSM-5 zeolite may be found online at: http://materials.binghamton.edu/labs/zeolite/zeolite.html
71
For F-based zeolite syntheses, see: (a) Koller, H.; Wolker, A.; Eckert, H.; Panz, C.; Behrens, P. Angew.
Chem. Int. Ed. Engl. 1997, 36, 2823. (b) Koller, H.; Wolker, A.; Villaescusa, L. A.; Daz-Cabanas, M.
J.; Valencia, S.; Camblor, M. A. J. Am. Chem. Soc. 1999, 121, 3368.