Hydrolysis and condensation of ZIF-8 in water

Huifeng Zhang, Man Zhao, Yang Yang, Jerry Lin

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Recent studies have shown that zeolitic imidazolate framework-8 (ZIF-8) crystallites are not stable in aqueous solution under ambient conditions. When immersed in water, ZIF-8 crystallites are hydrolyzed to zinc and imidazolate ions, which can be condensed to form a new solid substance upon removal of water by evaporation. The present work demonstrates such ZIF-8 phase shift substance is of crystalline structure but does not belong to any known (pseudo)polymorphs of ZIF-8, ZIF-L, dia(Zn), or decomposed product of ZIF-8: Zn(OH)2 and 2-methylimidazole. FTIR characterization shows the co-existence of Zn–O and Zn–N bond in the new substance, confirming the partial cleavage of Zn–N bond in ZIF-8 building unit in the hydrolysis step. EDS quantification for the ZIF-8 phase shift substance gives a C:N:Zn:O atomic ratio of 40:20:5:4. Based on EDS and FTIR results, the chemical formula of Zn5(HMIM)4(MIM)6(OH)4 for the building unit of such substance is proposed consisting of four partially hydrolyzed and one undisturbed secondary ZIF-8 building units. The ZIF-8 phase shift substance is crystalline with a nearly identical atomic composition as ZIF-8 (except for increased oxygen content), suggesting it might be a novel pseudo-polymorph of ZIF-8. The hydrolysis and condensation of ZIF-8 can be described by a mechanism that includes (1) hydrolysis of ZIF-8 through cleavage of Zn–N bond to form zinc and imidazolate ions and partially hydrolyzed ZIF-8 units and (2) condensation of these ions and clusters with the help of hydrogen bond to form the new structure of ZIF-8 phase shift substance.

Original languageEnglish (US)
Article number109568
JournalMicroporous and Mesoporous Materials
Volume288
DOIs
StatePublished - Nov 1 2019
Externally publishedYes

Fingerprint

Phase shift
hydrolysis
Condensation
Hydrolysis
phase shift
condensation
Water
Ions
Polymorphism
Crystallites
water
crystallites
Zinc
Energy dispersive spectroscopy
cleavage
zinc
Crystalline materials
ions
Hydrogen bonds
Evaporation

Keywords

  • Hydrolysis mechanism
  • Hydrostability
  • Zeolitic imidazolate frameworks
  • ZIF-8

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials

Cite this

Hydrolysis and condensation of ZIF-8 in water. / Zhang, Huifeng; Zhao, Man; Yang, Yang; Lin, Jerry.

In: Microporous and Mesoporous Materials, Vol. 288, 109568, 01.11.2019.

Research output: Contribution to journalArticle

Zhang, Huifeng ; Zhao, Man ; Yang, Yang ; Lin, Jerry. / Hydrolysis and condensation of ZIF-8 in water. In: Microporous and Mesoporous Materials. 2019 ; Vol. 288.
@article{937eba8658b7445791e8465952969bcc,
title = "Hydrolysis and condensation of ZIF-8 in water",
abstract = "Recent studies have shown that zeolitic imidazolate framework-8 (ZIF-8) crystallites are not stable in aqueous solution under ambient conditions. When immersed in water, ZIF-8 crystallites are hydrolyzed to zinc and imidazolate ions, which can be condensed to form a new solid substance upon removal of water by evaporation. The present work demonstrates such ZIF-8 phase shift substance is of crystalline structure but does not belong to any known (pseudo)polymorphs of ZIF-8, ZIF-L, dia(Zn), or decomposed product of ZIF-8: Zn(OH)2 and 2-methylimidazole. FTIR characterization shows the co-existence of Zn–O and Zn–N bond in the new substance, confirming the partial cleavage of Zn–N bond in ZIF-8 building unit in the hydrolysis step. EDS quantification for the ZIF-8 phase shift substance gives a C:N:Zn:O atomic ratio of 40:20:5:4. Based on EDS and FTIR results, the chemical formula of Zn5(HMIM)4(MIM)6(OH)4 for the building unit of such substance is proposed consisting of four partially hydrolyzed and one undisturbed secondary ZIF-8 building units. The ZIF-8 phase shift substance is crystalline with a nearly identical atomic composition as ZIF-8 (except for increased oxygen content), suggesting it might be a novel pseudo-polymorph of ZIF-8. The hydrolysis and condensation of ZIF-8 can be described by a mechanism that includes (1) hydrolysis of ZIF-8 through cleavage of Zn–N bond to form zinc and imidazolate ions and partially hydrolyzed ZIF-8 units and (2) condensation of these ions and clusters with the help of hydrogen bond to form the new structure of ZIF-8 phase shift substance.",
keywords = "Hydrolysis mechanism, Hydrostability, Zeolitic imidazolate frameworks, ZIF-8",
author = "Huifeng Zhang and Man Zhao and Yang Yang and Jerry Lin",
year = "2019",
month = "11",
day = "1",
doi = "10.1016/j.micromeso.2019.109568",
language = "English (US)",
volume = "288",
journal = "Microporous and Mesoporous Materials",
issn = "1387-1811",
publisher = "Elsevier",

}

TY - JOUR

T1 - Hydrolysis and condensation of ZIF-8 in water

AU - Zhang, Huifeng

AU - Zhao, Man

AU - Yang, Yang

AU - Lin, Jerry

PY - 2019/11/1

Y1 - 2019/11/1

N2 - Recent studies have shown that zeolitic imidazolate framework-8 (ZIF-8) crystallites are not stable in aqueous solution under ambient conditions. When immersed in water, ZIF-8 crystallites are hydrolyzed to zinc and imidazolate ions, which can be condensed to form a new solid substance upon removal of water by evaporation. The present work demonstrates such ZIF-8 phase shift substance is of crystalline structure but does not belong to any known (pseudo)polymorphs of ZIF-8, ZIF-L, dia(Zn), or decomposed product of ZIF-8: Zn(OH)2 and 2-methylimidazole. FTIR characterization shows the co-existence of Zn–O and Zn–N bond in the new substance, confirming the partial cleavage of Zn–N bond in ZIF-8 building unit in the hydrolysis step. EDS quantification for the ZIF-8 phase shift substance gives a C:N:Zn:O atomic ratio of 40:20:5:4. Based on EDS and FTIR results, the chemical formula of Zn5(HMIM)4(MIM)6(OH)4 for the building unit of such substance is proposed consisting of four partially hydrolyzed and one undisturbed secondary ZIF-8 building units. The ZIF-8 phase shift substance is crystalline with a nearly identical atomic composition as ZIF-8 (except for increased oxygen content), suggesting it might be a novel pseudo-polymorph of ZIF-8. The hydrolysis and condensation of ZIF-8 can be described by a mechanism that includes (1) hydrolysis of ZIF-8 through cleavage of Zn–N bond to form zinc and imidazolate ions and partially hydrolyzed ZIF-8 units and (2) condensation of these ions and clusters with the help of hydrogen bond to form the new structure of ZIF-8 phase shift substance.

AB - Recent studies have shown that zeolitic imidazolate framework-8 (ZIF-8) crystallites are not stable in aqueous solution under ambient conditions. When immersed in water, ZIF-8 crystallites are hydrolyzed to zinc and imidazolate ions, which can be condensed to form a new solid substance upon removal of water by evaporation. The present work demonstrates such ZIF-8 phase shift substance is of crystalline structure but does not belong to any known (pseudo)polymorphs of ZIF-8, ZIF-L, dia(Zn), or decomposed product of ZIF-8: Zn(OH)2 and 2-methylimidazole. FTIR characterization shows the co-existence of Zn–O and Zn–N bond in the new substance, confirming the partial cleavage of Zn–N bond in ZIF-8 building unit in the hydrolysis step. EDS quantification for the ZIF-8 phase shift substance gives a C:N:Zn:O atomic ratio of 40:20:5:4. Based on EDS and FTIR results, the chemical formula of Zn5(HMIM)4(MIM)6(OH)4 for the building unit of such substance is proposed consisting of four partially hydrolyzed and one undisturbed secondary ZIF-8 building units. The ZIF-8 phase shift substance is crystalline with a nearly identical atomic composition as ZIF-8 (except for increased oxygen content), suggesting it might be a novel pseudo-polymorph of ZIF-8. The hydrolysis and condensation of ZIF-8 can be described by a mechanism that includes (1) hydrolysis of ZIF-8 through cleavage of Zn–N bond to form zinc and imidazolate ions and partially hydrolyzed ZIF-8 units and (2) condensation of these ions and clusters with the help of hydrogen bond to form the new structure of ZIF-8 phase shift substance.

KW - Hydrolysis mechanism

KW - Hydrostability

KW - Zeolitic imidazolate frameworks

KW - ZIF-8

UR - http://www.scopus.com/inward/record.url?scp=85068144836&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85068144836&partnerID=8YFLogxK

U2 - 10.1016/j.micromeso.2019.109568

DO - 10.1016/j.micromeso.2019.109568

M3 - Article

AN - SCOPUS:85068144836

VL - 288

JO - Microporous and Mesoporous Materials

JF - Microporous and Mesoporous Materials

SN - 1387-1811

M1 - 109568

ER -