Host-guest-driven copolymerization of tetraphosphonate cavitands.
The outstanding complexing properties of tetraphosphonate cavitands towards N-methylpyridinium salts were exploited to realise a new class of linear and cyclic AABB supramolecular polymers through host-guest interactions. The effectiveness of the selected self-association processes was tested by (1)H NMR studies, whereas microcalorimetric analyses clarified the binding thermodynamics and revealed the possibility of tuning entropic contributions by acting on the flexibility of the guest linker. Although the formation of linear polymeric chains for a rigid system was demonstrated by X-ray analysis, the presence of a concentration-dependent ring-chain equilibrium was indicated by solution viscosity measurements in the case of a very flexible ditopic BB guest co-monomer.
Dipartimento di Chimica Organica e Industriale and Unità INSTM, UdR Parma, Università di Parma, Viale G. P. Usberti 17/a, 43124 Parma, Italy.
Francesca
F
Tancini
Roger M
RM
Yebeutchou
Laura
L
Pirondini
Rita
R
De Zorzi
Silvano
S
Geremia
Oren A
OA
Scherman
Enrico
E
Dalcanale
D018360:Crystallography, X-Ray; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D063065:Organophosphonates / Q000737:chemistry*; D058105:Polymerization; D011726:Pyridinium Compounds / Q000737:chemistry*; D012492:Salts; D013816:Thermodynamics
D063065:Organophosphonates; D011726:Pyridinium Compounds; D012492:Salts