Details
Original language | English |
---|---|
Pages (from-to) | 3348-3359 |
Number of pages | 12 |
Journal | Inorganic chemistry |
Volume | 57 |
Issue number | 6 |
Early online date | 2 Mar 2018 |
Publication status | Published - 19 Mar 2018 |
Abstract
Postsynthetic modification of metal-organic frameworks is an important method to tailor their properties. We report on the nitrile oxide-alkyne cycloaddition (NOAC) as a modification tool, a reaction requiring neither strained alkynes nor a catalyst. This is demonstrated with the reaction of nitrile oxides with PEPEP-PIZOF-15 and -19 at room temperature. PIZOF-15 and -19 are porous Zr-based MOFs (BET surface areas 1740 and 960 m2 g-1, respectively) consisting of two mutually interpenetrating UiO-type frameworks with linkers of the type -O2C[PE-P(R1,R2)-EP]CO2- (P, phenylene; E, ethynylene; R1 and R2, side chains at the central benzene ring with R1 = R2 = OCH2C≡CH or R1 = OCH2C≡CH and R2 = O(CH2CH2O)3Me). Their syntheses, using benzoic acid as a modulator, and their characterization are reported herein. The propargyloxy (OCH2C≡CH) side chains contain the ethyne moieties needed for NOAC. Formation of nitrile oxides through oxidation of oximes in aqueous ethanolic solution in the presence of PEPEP-PIZOF-15 and -19 resulted in the reaction of 96-100% of the ethyne moieties to give isoxazoles. Thereby the framework was preserved. The type of nitrile oxide RCNO was greatly varied with R being isopentyl, tolyl, 2-pyridyl, and pentafluorophenyl. A detailed NMR spectroscopic investigation showed the formation of the 3,5-disubstituted isoxazole to be clearly favored (≥96%) over that of the constitutional isomeric 3,4-disubstituted isoxazole, except for one example.
ASJC Scopus subject areas
- Chemistry(all)
- Physical and Theoretical Chemistry
- Chemistry(all)
- Inorganic Chemistry
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In: Inorganic chemistry, Vol. 57, No. 6, 19.03.2018, p. 3348-3359.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Postsynthetic Modification of Metal-Organic Frameworks through Nitrile Oxide-Alkyne Cycloaddition
AU - Von Zons, Tobias
AU - Brokmann, Luisa
AU - Lippke, Jann
AU - Preuße, Thomas
AU - Hülsmann, Miriam
AU - Schaate, Andreas
AU - Behrens, Peter
AU - Godt, Adelheid
N1 - © 2018 American Chemical Society
PY - 2018/3/19
Y1 - 2018/3/19
N2 - Postsynthetic modification of metal-organic frameworks is an important method to tailor their properties. We report on the nitrile oxide-alkyne cycloaddition (NOAC) as a modification tool, a reaction requiring neither strained alkynes nor a catalyst. This is demonstrated with the reaction of nitrile oxides with PEPEP-PIZOF-15 and -19 at room temperature. PIZOF-15 and -19 are porous Zr-based MOFs (BET surface areas 1740 and 960 m2 g-1, respectively) consisting of two mutually interpenetrating UiO-type frameworks with linkers of the type -O2C[PE-P(R1,R2)-EP]CO2- (P, phenylene; E, ethynylene; R1 and R2, side chains at the central benzene ring with R1 = R2 = OCH2C≡CH or R1 = OCH2C≡CH and R2 = O(CH2CH2O)3Me). Their syntheses, using benzoic acid as a modulator, and their characterization are reported herein. The propargyloxy (OCH2C≡CH) side chains contain the ethyne moieties needed for NOAC. Formation of nitrile oxides through oxidation of oximes in aqueous ethanolic solution in the presence of PEPEP-PIZOF-15 and -19 resulted in the reaction of 96-100% of the ethyne moieties to give isoxazoles. Thereby the framework was preserved. The type of nitrile oxide RCNO was greatly varied with R being isopentyl, tolyl, 2-pyridyl, and pentafluorophenyl. A detailed NMR spectroscopic investigation showed the formation of the 3,5-disubstituted isoxazole to be clearly favored (≥96%) over that of the constitutional isomeric 3,4-disubstituted isoxazole, except for one example.
AB - Postsynthetic modification of metal-organic frameworks is an important method to tailor their properties. We report on the nitrile oxide-alkyne cycloaddition (NOAC) as a modification tool, a reaction requiring neither strained alkynes nor a catalyst. This is demonstrated with the reaction of nitrile oxides with PEPEP-PIZOF-15 and -19 at room temperature. PIZOF-15 and -19 are porous Zr-based MOFs (BET surface areas 1740 and 960 m2 g-1, respectively) consisting of two mutually interpenetrating UiO-type frameworks with linkers of the type -O2C[PE-P(R1,R2)-EP]CO2- (P, phenylene; E, ethynylene; R1 and R2, side chains at the central benzene ring with R1 = R2 = OCH2C≡CH or R1 = OCH2C≡CH and R2 = O(CH2CH2O)3Me). Their syntheses, using benzoic acid as a modulator, and their characterization are reported herein. The propargyloxy (OCH2C≡CH) side chains contain the ethyne moieties needed for NOAC. Formation of nitrile oxides through oxidation of oximes in aqueous ethanolic solution in the presence of PEPEP-PIZOF-15 and -19 resulted in the reaction of 96-100% of the ethyne moieties to give isoxazoles. Thereby the framework was preserved. The type of nitrile oxide RCNO was greatly varied with R being isopentyl, tolyl, 2-pyridyl, and pentafluorophenyl. A detailed NMR spectroscopic investigation showed the formation of the 3,5-disubstituted isoxazole to be clearly favored (≥96%) over that of the constitutional isomeric 3,4-disubstituted isoxazole, except for one example.
UR - http://www.scopus.com/inward/record.url?scp=85044108375&partnerID=8YFLogxK
U2 - 10.1021/acs.inorgchem.8b00126
DO - 10.1021/acs.inorgchem.8b00126
M3 - Article
C2 - 29498270
AN - SCOPUS:85044108375
VL - 57
SP - 3348
EP - 3359
JO - Inorganic chemistry
JF - Inorganic chemistry
SN - 0020-1669
IS - 6
ER -