Coordination Polymer-Mediated Molecular Surgery for Precise Interconversion of Dicyclobutane Compounds

Abstract

A Cd(II)-based coordination polymer {[Cd2(5-F-1,3-bpeb)2(FBA)4]·H2O} n (CP 1 ) was obtained from Cd(II) salt, 5-fluoro-1,3-bis[2-(4-pyridyl)ethenyl]benzene (5-F-1,3-bpeb), and p-fluorobenzoic acid (HFBA). Within the one-dimensional chain structure of CP 1 , a pair of 5-F-1,3-bpeb was arranged in a face-to-face style. Upon UV irradiation and heat treatment, multiple cyclobutane isomers, including specific monocyclobutanes (1 with an endo-cyclobutane ring in CP 1 -1 and 1′ with an exo-cyclobutane ring in CP 1 -1′) and dicyclobutanes (endo,endo-dicyclobutane 2α in CP 1 -2α, exo,endo-dicyclobutane 2β in CP 1 -2β, and exo,exo-dicyclobutane 2γ in CP 1 -2γ) were stereoselectively produced. These isomers could be interconverted inside the CP via cutting/coupling specific bonds, which may be regarded as a type of molecular surgery. The precision of cutting/coupling relied on the thermal stability of the cyclobutanes and the alignment of the reactive alkene centers. The conversion processes were tracked through nuclear magnetic resonance, in situ powder X-ray diffraction, and IR spectroscopy. This approach can be considered as skeletal editing to construct complex organic compounds directly from one precursor.

Revealing Solid–Liquid Equilibrium Behavior of 4-Fluorobenzoic Acid in 12 Pure Solvents from 283.15 to 323.15 K by Experiments and Molecular Simulations

“…It serves as a vital starting material in organic synthesis and can be utilized as a precursor for various organic compounds, including aromatic ethers, ketones, esters, and amides. 1,2 4FBA is commonly employed for introducing fluorine atoms. In pharmaceutical synthesis, the introduction of fluorinated compounds often enhances the chemical stability of molecules and alters their interaction with biological systems, thereby improving drug bioavailability, pharmacokinetics, and biological activity.…”

“…4-Fluorobenzoic acid (4FBA, C 7 H 5 FO 2 , CAS: 456-22-4, Figure ) is an aromatic carboxylic acid substituted with a fluorine atom. It serves as a vital starting material in organic synthesis and can be utilized as a precursor for various organic compounds, including aromatic ethers, ketones, esters, and amides. , 4FBA is commonly employed for introducing fluorine atoms. In pharmaceutical synthesis, the introduction of fluorinated compounds often enhances the chemical stability of molecules and alters their interaction with biological systems, thereby improving drug bioavailability, pharmacokinetics, and biological activity. , Furthermore, fluorinated organic molecules typically exhibit higher electron affinity and stability, making them useful in applications such as organic semiconductors, fluorescent probes, and material surface modification agents .…”

Research on single-crystal-to-single-crystal photoaddition and extension of Schmidt's rule in topological chemistry

“…Topological chemistry studies provide detailed and specific information on the relationship between the structure and properties of substances at the atomic level. 1–20 Research in this field on coordination polymers (some of them are also known as MOFs) synthesized with bis[2-(4-pyridyl)ethenyl]benzene (bpeb) has attracted great attention from researchers, and a lot of interesting results have been obtained. 4–14…”

“…1–20 Research in this field on coordination polymers (some of them are also known as MOFs) synthesized with bis[2-(4-pyridyl)ethenyl]benzene (bpeb) has attracted great attention from researchers, and a lot of interesting results have been obtained. 4–14…”

“…Topological chemistry studies provide detailed and specific information on the relationship between the structure and properties of substances at the atomic level. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Research in this field on coordination polymers (some of them are also known as MOFs) synthesized with bis[2-(4-pyridyl)ethenyl] benzene (bpeb) has attracted great attention from researchers, and a lot of interesting results have been obtained. [4][5][6][7][8][9][10][11][12][13][14] According to Schmidt's rule, the CC pairs in the solid phase must meet two requirements for photoaddition, namely: the spacing between CC pairs, d, is less than 4.2 Å and the angle between them, θ, is as close as possible to 0°.…”