Books
in black and white
Main menu
Share a book About us Home
Books
Biology Business Chemistry Computers Culture Economics Fiction Games Guide History Management Mathematical Medicine Mental Fitnes Physics Psychology Scince Sport Technics
Ads

The porphyrin handbook - Kadish K.M.

Kadish K.M. The porphyrin handbook - Academic press, 2000. - 368 p.
Download (direct link): kadishsmishgulilard2000.djvu
Previous << 1 .. 190 191 192 193 194 195 < 196 > 197 198 199 200 201 202 .. 240 >> Next

99 44 pyridine 28.3 CHCI,
298 UV-Vis 242
100 44 isoquinoline 28.8 CHCI,
298 UV-Vis 242
101 44 butylamine 27.8 CHCI,
298 UV-Vis 242
102 45 azetidine 33.5 CHCI,
298 UV-Vis 242
103 45 diethylamine 20.7 CHCI,
298 UV-Vis 242
104 45 pyrrolidine 33.3 CHCI,
298 UV-Vis 242
105 45 piperidine 30.8 CHCI,
298 UV-Vis 242
106 45 3-pyrroline 30.5 CHCI,
298 UV-Vis 242
107 45 pyridine 26.1 CHCI,
298 UV-Vis 242
108 45 isoquinoline 27.9 CHCI,
298 UV-Vis 242
109 45 butylamine 26.8 CHCI,
298 UV-Vis 242
110 43 azetidine 28.8 CHCI,
298 UV-Vis 242
111 43 diethylamine 17 CHCI,
298 UV-Vis 242
112 43 pyrrolidine 28.2 CHCI,
298 UV-Vis 242
113 43 piperidine 32.3 CHCI,
298 UV-Vis 242
114 43 3-pyrroline 25.2 CHCI,
298 UV-Vis 242
115 43 pyridine 19.4 CHCI,
298 UV-Vis 242
116 43 isoquinoline 19.8 CHCI,
298 UV-Vis 242
117 43 butylamine 23.1 CHCI,
298 UV-Vis 242
118 46 1,2,4-triazole 14.8
CHCl,/3% CD,OD 'H NMR 29
119 47 1,2,4-triazole 24.3
CHCl,/3% CD,OD 'H NMR 30
120 48 1,6-diaminohexane 32.9 CH.Cb
288 UV-Vis 60
121 48 1,8-diaminooctane 34.9
CH,CI2 288 UV-Vis 60
122 48 1,10-diaminodecane 34.4 CHoCb
288 UV-Vis 60
123 48 1,12-diamino-dodecane 31.6 CH.Cb
288 UV-Vis 60
124 48 butylamine 18.9 CH.Cb
288 UV-Vis 60
125 48 ethylenediamine 19.1
CH,CI2 288 UV-Vis 60
126 48 butylamine 18.4 CHXh
288 UV-Vis 60
"To have an idea of the relationship between the magnitude of - Ѱ of
complexation and the concentration of the target molecule, the
equilibrium constant of )3 M _1 corresponds to 17.1 kJ/mol, the lower
limit of the concentration of the target molecule is mM level. Similarly,
for binding a molecule in a |.iM level. - Ѱ should be larger than 34.2
kJ/mol, for nM level binding. - AG() > 51.3 kJ/mol. and for pM level
binding. - AG > 68.5 kJ/mol at 298 K.
46/Porphyrins and Metalloporphyrins as Receptor Models
291
B. AMINO-ACID RECOGNITION IN WATER
Table 2 summarizes the binding free energies of amino-acid derivatives by
porphyrin hosts. Three recognition groups should be introduced for the
design of amino-acid hosts: one for the amino group, one lor the carboxyl
group, and one for the side-chain group. Gaudemer and coworkers reported
the use of metalloporphyrins for amino-acid recognition in water.74
Tetrakis(4-methylpyridinium)porphyrin (52) and its zinc (53) or cobalt
complexes (27) were used as hosts for amino acids in water. In these
systems, the coordinating interaction between zinc and the amino group is
the major driving force for complex formation. However, interactions
between the porphyrin and the amino acids (ligand-ligand interactions)
also contributed to the overall free-energy
changes. To elucidate ligand-ligand interactions, the use of the
relatively weak Lewis acid, zinc, is advantageous over a strong Lewis
acid such as cobalt. Zinc porphyrin 53 binds amino acids with association
constants ranging from 60 to 1200 M 1 at 295 and pH 9. For free-base
porphyrin 52, only aromatic amino acids such as tryptophan and
phenylalanine formed a complex with reasonably large association
constants ranging from 500 to 900 M The driving force for this
Previous << 1 .. 190 191 192 193 194 195 < 196 > 197 198 199 200 201 202 .. 240 >> Next