Journal article
Supramolecular Sandwiches: Halogen-Bonded Coformers Direct [2+2] Photoreactivity in Two-Component Cocrystals
Molecules (Basel, Switzerland), Vol.25(4), p.907
02/18/2020
DOI: 10.3390/molecules25040907
PMCID: PMC7070622
PMID: 32085511
Abstract
The halogen-bond (X-bond) donors 1,3- and 1,4-diiodotetrafluorobenzene (
1,3-di-I-tFb
and
1,4-di-I-tFb
, respectively) form cocrystals with
trans
-1,2-bis(2-pyridyl)ethylene (
2,2′-bpe
) assembled by N···I X-bonds. In each cocrystal, 2(
1,3-di-I-tFb
)·2(
2,2′-bpe
) and (
1,4-di-I-tFb
)·(
2,2′-bpe
), the donor molecules support the C=C bonds of
2,2′-bpe
to undergo an intermolecular [2+2] photodimerization. UV irradiation of each cocrystal resulted in stereospecific and quantitative conversion of
2,2′-bpe
to
rctt
-tetrakis(2-pyridyl)cyclobutane (
2,2′-tpcb
). In each case, the reactivity occurs via face-to-face
π
-stacked columns wherein nearest-neighbor pairs of
2,2′-bpe
molecules lie sandwiched between X-bond donor molecules. Nearest-neighbor C=C bonds are stacked criss-crossed in both cocrystals. The reactivity was ascribed to the olefins undergoing pedal-like motion in the solid state. The stereochemistry of
2,2′-tpcb
is confirmed in cocrystals 2(
1,3-di-I-tFb
)·(
2,2′-tpcb
) and (
1,4-di-I-tFb
)·(
2,2′-tpcb
).
Details
- Title: Subtitle
- Supramolecular Sandwiches: Halogen-Bonded Coformers Direct [2+2] Photoreactivity in Two-Component Cocrystals
- Creators
- Jay Quentin - Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA; (J.Q.); (D.C.S.)Dale C Swenson - Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA; (J.Q.); (D.C.S.)Leonard R MacGillivray - Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA; (J.Q.); (D.C.S.)
- Resource Type
- Journal article
- Publication Details
- Molecules (Basel, Switzerland), Vol.25(4), p.907
- DOI
- 10.3390/molecules25040907
- PMID
- 32085511
- PMCID
- PMC7070622
- NLM abbreviation
- Molecules
- ISSN
- 1420-3049
- eISSN
- 1420-3049
- Publisher
- MDPI
- Grant note
- DOI: 10.13039/100006445, name: National Science Foundation, award: DMR-1708673
- Language
- English
- Date published
- 02/18/2020
- Academic Unit
- Pharmaceutical Sciences and Experimental Therapeutics; Chemistry
- Record Identifier
- 9984216703402771
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