Chemistry Reference
In-Depth Information
TABLE 1.1 Six Categories of Noncovalent Intermolecular Interactions
Interaction
Description and Bond Strengths
Selected Example
.1 kcal mol
21
; dynamic induced dipole-
dipole interactions
(London)
dispersion
forces
2-3 kcal mol
21
(face-face), 3-5 kcal
mol
21
(edge-face); attractive forces
between electron-rich interior with
electron-poor exterior
Stacking
1-10 kcal mol
21
, association of nonpolar
complements in aqueous or polar media
Hydrophobic
.1 kcal mol
21
(weak), 1-4 kcal mol
21
(moderate), 5-10 kcal mol
21
(strong);
donor-acceptor interaction involving
hydrogen atom as donor and base
(electron pair) as proton acceptor
Hydrogen
bonding
1-10 kcal mol
21
(dipole-dipole), 10-
30 kcal mol
21
(ion-dipole), .45 kcal
mol
21
(ion-ion); Coulombic attraction
between opposite charges, highly
dependent on media
Electrostatic
5-90 kcal mol
21
; metal -ligand
coordination, ligand donates electron
pair(s) to center
Dative bonding
Association strengths are for systems in chloroform.
1.2. MAIN-CHAIN VERSUS SIDE-CHAIN SUPRAMOLECULAR
POLYMERS
The concept of supramolecular polymers containing multiple hydrogen bonding units
was introduced over a decade ago by Jean-Marie Lehn (Lehn 1993). In this study,
three-point hydrogen bonding between bifunctional diamidopyridine and thymine
