Allosteric Guest Binding in Chiral Zirconium(IV) Double Decker Porphyrin Cages.
Jeroen P J BruekersMatthijs A HellinghuizenNicolas VanthuynePaul TinnemansPieter J GilissenWybren Jan BumaJean-Valère NaubronJeanne CrassousJohannes A A W ElemansRoeland J M NoltePublished in: European journal of organic chemistry (2021)
Chiral zirconium(IV) double cage sandwich complex Zr(1)2 has been synthesized in one step from porphyrin cage H21. Zr(1)2 was obtained as a racemate, which was resolved by HPLC and the enantiomers were isolated in >99.5 % ee. Their absolute configurations were assigned on the basis of X-ray crystallography and circular dichroism spectroscopy. Vibrational circular dichroism (VCD) experiments on the enantiomers of Zr(1)2 revealed that the chirality around the zirconium center is propagated throughout the whole cage structure. The axial conformational chirality of the double cage complex displayed a VCD fingerprint similar to the one observed previously for a related chiral cage compound with planar and point chirality. Zr(1)2 shows fluorescence, which is quenched when viologen guests bind in its cavities. The binding of viologen and dihydroxybenzene derivatives in the two cavities of Zr(1)2 occurs with negative allostery, the cooperativity factors α (=4 K2/K1) being as low as 0.0076 for the binding of N,N'-dimethylviologen. These allosteric effects are attributed to a pinching of the second cavity as a result of guest binding in the first cavity.
Keyphrases
- pet imaging
- capillary electrophoresis
- single molecule
- small molecule
- energy transfer
- photodynamic therapy
- dna binding
- high resolution
- binding protein
- mass spectrometry
- molecular dynamics simulations
- ionic liquid
- ms ms
- molecular dynamics
- magnetic resonance imaging
- magnetic resonance
- high performance liquid chromatography
- metal organic framework
- computed tomography
- positron emission tomography
- simultaneous determination
- tandem mass spectrometry
- liquid chromatography
- contrast enhanced