Formation Energies and Chemical Environment

1
Examples of Chiral Molecules and Effects on
Surface D.D. Johnson MSE 280 Into to Eng. Matls.
2
Thiol-Stabilized Au Nanoclusters
Thiol H-S-CH2-(CH2)x-CH3
-S-CH2-
Molecular self-assembly to organize nanoclusters
into arrays for nanoelectronics devices. Narrow
dispersity, 1.7 nm diameter clusters. J.
Hutchinson, Oregon

• Functional devices often require supports.

3
Bio-sensor via DNA/Au-nanoclusters
Mirkin et al., Nature 382, 607 (1996) 
Au particle change color when exposed to anthrax.
Functional control on size. 8 and 31 nm Au
particles.
http//www.chem.nwu.edu/mkngrp/nano/nano2.html
See also, Yi Lu (UIUC) detection of metal (Pb)
poisons (2003).
4
Chiral Surfaces Show Enantiospecific Properties
- 3-methyl-cyclohexanone/Cu(643) Horvath
Gellman, CMU - glucose electro-oxidation/Pt(hkl)
Attard et al., Cardiff
Reactions at surfaces (surface chemistry) depend
on symmetry of surface and symmetry of molecules.
5
Chiral Surfaces Show Enantiospecific Properties
Lysine is a chiral molecule. What happens when
Cu(001) surface is exposed to Lysine?
Surfaces reconstructs due to symmetry of
molecules.
6
SPLENDA aka Sucralose Chlorinated Sucrose
According to market research firm IRI, as
reported in the Wall Street Journal, Splenda sold
212 million in 2006 in the US while Equal sold
48.7 million
Sucralose is approximately 600 times sweeter than
sucrose (table sugar), twice as sweet as
saccharin, and four times as sweet as aspartame.
From sucrose By -OH to Cl
Figures from http//en.wikipedia.org/wiki/Sucral
ose
Processing 3 of the hydroxyl groups are replaced
with chlorine atoms to produce 1,6-dichloro-1,6-di
deoxy-ß-D-fructo-furanosyl 4-chloro-4-deoxy-a-D-ga
lactopyranoside or C12H19Cl3O8.
7
Sucrose (table sugar) is a disaccharide (glucose
fructose) with the molecular formula C12H22O11.
Reacting sucrose with sulfuric acid dehydrates
the sucrose and forms elemental carbon
C12H22O11 H2SO4 (w/ catalyst) --gt 12 C 11 H2O
1 gram of sugar, like that of any other
carbohydrate, provides 4 calories in a person's
daily diet. 4 grams 1 level teaspoon
8
SPLENDA Chlorinated Sucrose
http//en.wikipedia.org/wiki/Sucralose
Though marketed in the U.S. as a No calorie
sweetener, Splenda actually contains slightly
more calories than the same mass of sugar (391
kcal per 100 g vs 390 kcal per 100 g for white
granulated sugar).
Splendas packaging states that a serving of 1
gram contains zero calories, Splenda actually
contains two calories per gram.

• Because Splenda has a relatively small amount of
  sucralose, little of which is metabolized,
  virtually all of Splendas caloric content
  derives from the fluffed dextrose or maltodextrin
  filler that gives Splenda its volume.
• Like other carbohydrates (e.g. sugar), dextrose
  and maltodextrin have 4 calories per gram.

9
According to the Splenda International Patent
A23L001-236 and PEP Review 90-1-4 (July 1991),
sucralose is synthesized by this five-step
process 1. sucrose is tritylated with trityl
chloride in the presence of dimethylformamide and
4-methylmorpholine and the tritylated sucrose is
then acetylated with acetic anhydride, 2. the
resulting TRISPA (6,1',6'-tri-O-trityl-penta-O-ace
tylsucrose) is chlorinated with hydrogen chloride
in the presence of toluene, 3. the resulting
4-PAS (sucrose 2,3,4,3',4'-pentaacetate) is
heated in the presence of methyl isobutyl ketone
and acetic acid, 4. the resulting 6-PAS (sucrose
2,3,6,3',4'-pentaacetate) is chlorinated with
thionyl chloride in the presence of toluene and
benzyltriethylammonium chloride, and 5. the
resulting TOSPA (sucralose pentaacetate) is
treated with methanol (wood alcohol, a poison) in
the presence of sodium methoxide to produce
sucralose (or SPLENDA). Splenda marketers
stress that sucralose is made from sugar but is
derived from this sugar through a process that
selectively substitutes three atoms of chlorine
for three hydrogen-oxygen groups on the sucrose
molecule.
The chemicals used to synthesize sucralose in the
five-step process Acetone, Acetic acid, Acetyl
alcohol, Acetic anhydride, Ammonium chloride,
Benzene, Chlorinated sulfates, Ethyl alcohol,
Isobutyl ketones, Formaldehyde, Hydrogen
chloride, Lithium chloride, Methanol, Sodium
methoxide, Sulfuryl chloride, Trityl chloride,
Toluene, Thionyl chloride.
(from http//www.splendaexposed.com from info
based on book from Dr. Janet Starr Hull)