Selective product amplification of thymine photodimer by recognition-directed supramolecular assistance.
Two symmetric ditopic supramolecular templates (1 and 2) each presenting two hydrogen bonding recognition subunits were synthesized. Each such subunit comprises the same donor and acceptor pattern, capable of binding a substrate molecule with complementary hydrogen bonding groups to form a supramolecular complex. Substrate molecules, such as thymine or uracil derivatives, yield 2 : 1 complexes with the acceptors involving two hydrogen bonds to each subunit with ideal orientation for subsequent [2 + 2] dimerization upon photoirradiation. Selective syn photoproduct formation and concomitant suppression of the trans isomer are favored by orientation of the two guest nucleobases within the template cleft. Complementary donor and acceptor hydrogen bonding induced positioning of the two substrates and steric hindrance within the template clefts are responsible for the selective product formation.
Skene
W G
WG
Laboratoire de Chimie Supramoléculaire, ISIS-Université Louis Pasteur, 8, allée Gaspard Monge, BP 70028, 67083, Strasbourg cedex, France.
Berl
Volker
V
Risler
Hélène
H
Khoury
Richard
R
Lehn
Jean-Marie
JM
D002384:Catalysis; D018360:Crystallography, X-Ray; D019281:Dimerization; D006860:Hydrogen Bonding; D007700:Kinetics; D008027:Light; D009682:Magnetic Resonance Spectroscopy; D013941:Thymine / Q000737:chemistry*; D014498:Uracil / Q000737:chemistry
D014498:Uracil; D013941:Thymine