Background and Objective

Synthesis and Adsorption Properties of Three-Dimensional

Fluorinated Dianion-Bridged Porous Metal ComplexesM2 AnQi Wang

Noro Laboratory, Course in Environmental Adaptation Science

Adsorption Properties

Synthesis of [Cu(AF6)(3,3′-bpy)2]

Porous metal complexes

○ High specific surface area○ High crystallinity○ High structural diversity○ High flexibility

Porous metal complexes have attracted much attention as novel porous materials showing excellent

adsorption, separation, and catalytic properties.

Three-dimensional (3D) AF6-bridged porous metal complexes[1]

Conclusion and Future Work

References[1] S. Noro, T. Nakamura, NPG Asia Mater. 2017, 9, e433. [2] M. Eddaoudi, M. J. Zaworotko, et al., Nature 2013, 495, 80.[3] Infrared and Raman Spectra of Inorganic and Coordination Compounds, Part A: Theory and Applications in Inorganic Chemistry (Fifth Edition); K. Nakamoto, 1997, P216.

Research objective

Synthesis and characterization of 3D AF6-bridged porous

metal complexes with nonlinear 3,3′-bpy ligands

✓Representative porous metal complexes

✓3D porous frameworks bridged by both AF6 dianion and L

✓Excellent CO2 and olefin separation properties

Structural Characterization

C H N

Found (%) 43.18 2.95 10.08

Calcd (1·2H2O) (%) 43.36 3.64 10.11

C H N

Found (%) 38.81 2.55 8.94

Calcd (2·3H2O) (%) 38.96 3.60 9.09

Elemental analysis

✓Cu : AF62- : 3,3′-bpy = 1 : 1 : 2

shift of GeF62- vibration

bandshift of SiF62-

vibration band

IR spectra of SiF6-including compounds IR spectra of GeF6-including compounds

✓The Infrared spectra showed the

obvious shift of AF62- vibration

bands, suggested that there are

Cu-AF6 connections within the

target compounds.

Powder X-ray diffraction (PXRD) patterns

Estimated structure

✓The PXRD patterns showed the characteristic

diffraction peaks originated from the •••3,3′-bpy–

Cu–3,3′-bpy–Cu••• periodicities. The results of

elemental analysis, IR, and PXRD suggested that 1

and 2 have three-dimensional porous frameworks

bridged by AF6 dianions and 3,3′-bpy ligands.

BET surface area

1 (from CO2 data): 390 m2·g-1

2 (first step) : 345 m2·g-1

Adsorption/desorption isotherms of N2 at

77 K (1 and 2) and CO2 at 195 K (1).*

N2 at 77K (1)

N2 at 77K (2)

CO2 at 195K (1) CO2 at 195K

CO2 at 298K

N2 at 298K

N2 at 195K

*open symbols: adsorption

closed symbols: desorption

Adsorption/desorption isotherms of N2

and CO2 at 195 and 298 K in 1.*

✓ 1 showed type I curves and the N2 adsorption amount was considerably lower

than CO2, indicating that 1 has micropores that inhibit a pore diffusion of larger N2(kinetic diameter = 3.64 Å) compared with CO2 (kinetic diameter = 3.3 Å). The

high CO2 selectivity over N2 was observed at 298 K.

✓ 2 showed stepwise curves with a hysteresis at the second step, suggesting N2adsorption synchronized with a structure change at the second step.

➢ AF6-including copper complexes, [Cu(AF6)2(3,3′-bpy)2] (A = Si (1) and Ge (2)), were synthesized and structurally characterized.

From the experiments, it was suggested that both 1 and 2 have 3D AF6- and 3,3′-bpy-bridged porous frameworks.

➢ 1 showed high selective CO2 adsorption over N2 at 298 K and high stability for water, promising a repeated use under humid

condition.

➢ 2 exhibited the stepwise adsorption with a hysteresis at the second step, meaning the adsorption concomitantly with structural

change. This phenomenon is the first time among AF6-bridged metal complexes.

[3]

[M(AF6)(L)2]

(M = Cu, Zn, Ni, Fe; A = Si, Ge, Ti;

L = )(R = ｰCH=CHｰ,ｰC≡Cｰ)

Previous works

✓Limited to linear and

approximately linear

bridging ligands

To find new types of 3D AF6-bridged

porous metal complexes

This work

nonlinear 3,3′-bipyridine

(3,3′-bpy)

✓Different bridging mode from above ligands

Is it possible to synthesize 3D AF6-

bridged porous framework?

How are the porous properties?

metal ion

organic ligand

＋

✓ Structure determination using single

crystal X-ray diffraction analysis

✓ Evaluation of detailed CO2 separation

properties (adsorption speed, mixed gas

adsorption, CO2-adsorbed structure)

Vibration mode of AF62- dianion