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Three-Dimensional Porous Coordination Polymer Functionalized with Amide Groups Based on Tridentate Ligand: S

elective Sorption and Catalysis

Shinpei Hasegawa, Satoshi Horike, Ryotaro Matsuda, Shuhei Furukawa, Katsunori Mochizuki, Yoshinori Kinoshita, and Susumu

Kitagawa*

J. Am. Chem. Soc. 2007, 129, 2607-2614

演講者：江柏誼

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Porous Coordination Polymers (PCPs)

porous coordination polymer Susumu Kitagawa. Natue. 2006, 441, 584-585

[{RhII2(bza)4(2-mpyz)}n]

O

-O

benzoate(bza)

N

N

2-methylpyrazine(2-mpyz)

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PCPs have Characteristics

(1) well-ordered porous structures

(2) flexible and dynamic behaviors in response to guest molecules

(3) designable channel surface functionalities

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Strategies to Functionalize Channel Surfaces

I 、 immobilization of coordinatively unsaturated| (Open) Metal Sites (OMS)

Noro, S.; Kitagawa, S.; Yamashita, M.; Wada, T. Chem. Commun. 2002, 222-223.

{[ZnCu(2,4-pydca)2(H2O)3

(DMF)]·DMF}n

N

O

O-

O

-O

pyridine-2,4-dicarboxylate(2,4-pydca)

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Strategies to Functionalize Channel Surfaces (continued)

II 、 introduction of organic groups to provide guest-accessible Functional Organic Sites (FOS)

Kitaura, R.; Fujimoto, K.; Noro, S.; Kondo, M.; Kitagawa, S.; Angew. Chem. Int. Ed. 2002, 41, 133-135.

[{[Cu2(pzdc)2(dpyg)] ‧8H2O}n]1,2-dipyridylglycol (dpyg)

coordination site

guest interaction site

N

NO

-O

OO-

pyrazine-2,3-dicarboxylate(pzdc)

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FOS have Advantages

• Base-type catalyst is easy to create 。

• There are a variety of organic functional groups that can serve as active base sites 。

• A new types of catalysts constructed from metal-organic frameworks 。

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4-Btapa

1,3,5-Benzene Tricarboxylic AcidTris[N-(4-pyridyl)amide]

(4-btapa)

-NH electron acceptor

-C=O electron donor

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Synthesis of 4-Btapa

NH2N

4-aminopyridine

1.triethylamine, THF

2.dropwise addation

1,3,5-benzene tricarboxytrichloride

, THF, 0oC3.triethylamine, THF, stir 7 hour

O O

NH

O NH

NH

NN

N

4-btapa4.filtration and washed with THF

N

triethylamine

(1,3,5-benzene tricarboxytrichloride)

O

O

O

ClCl

ClTrimesoyl Chloride

(81%)

yellowish whitepowder

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Cd(NO3)2¡E4H2O

1. DMF2. 4-btapa/DMF

3. stir 3.5 hour4. filtration,washed with DMF

{[Cd(4-btapa)2(NO3)2]¡E6H2O¡E2DMF}n

1aunder vacuum for 7.5 hour at 140oC

{[Cd(4-btapa)2]¡E2NO3}n

1bon the methanol vapor for 30 hour

{[Cd(4-btapa)2(NO3)2]¡E6MeOH¡EyH2O}n

Synthesis of 1a, 1b, and 1c

yellowish whitepowder

(1a)

(1b)

(1c)colorless

(93%)

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ORTEP Drawing of 1a

Solid-state 113Cd CPMAS NMR spectrum of 1a

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Table 1. Selected Bond Distances (Å) and Angles (deg)

for {[Cd(4-btapa)2(NO3)2]·6H2O·2DMF}n (1a) Cd (1)-N1 2.372 (7) Cd1-N11 2.372 (8)

Cd1-N12 2.372 (8) Cd1-N13 2.372 (8)

Cd1-N14 2.372 (8) Cd1-N15 2.372 (7)

N11-Cd1-N1 90.8 (3) N12-Cd1-N1 90.8 (3)

N13-Cd1-N1   N14-Cd1-N1 89.2 (3)

N15-Cd1-N1   N12-Cd1-N11 90.8 (3)

N13-Cd1-N11 89.2 (3) N44-Cd1-N41 89.2 (3)

N15-Cd1-N11 180.0 (4) N13-Cd1-N12 89.2 (3)

N14-Cd1-N12 180.0 (4) N15-Cd1-N12 89.2 (3)

N14-Cd1-N13 90.8 (3) N15-Cd1-N13 90.8 (3)

N15-Cd1-N14 90.8 (3)

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Crystal Structure of 1a

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Two-Fold Interpenetrating 3-D Crystal Structure of 1a to Form Three-Dimension

4.7 X 7.3 Å2

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Crystal Structure of 1a to Form Another Type of Zigzag Channels

3.3 X 3.6 Å2

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The Amide Groups on the Channel Surface of 1a

Cd

O

N

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Thermogravimetric Analyses of 1a and 1c

at a heating rate of 10 °C min-1 under N2

Amount of guests in figures is based on one 4-btapa ligand of each compound.

{[Cd(4-btapa)2(NO3)2] ‧6H2

O‧2DMF}n

{[Cd(4-btapa)2(NO3)2] ‧6MeOH‧yH2O}n

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XRPD Patterns of 1a and 1b

1a simulation based on the single-crystal structure

the as-synthesized 1a

the desolvated compound 1b

compound 1c obtained by exposing 1b to methanol vapor for 30 h.

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XRPD Patterns for Desolvated Compound 1b Immersed in Slovent

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The Adsorption and Desorption Isotherms of 1b for Methanol

adsorption

desorption

P0 is the saturated vapor pressure, 102.3 kPa, of N2 (77 K), and16.94 kPa, of methanol (298 K).

hysteresis loop

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1H NMR (DMSO-d6) Spectra of 1a that Adsorbed Each Guest Molecule

malononitrile

ethyl cyanoacetate

cyanoacetic acid tert-butyl ester

2.9

0.7

0.6

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IR Spectra in the Region of C≡N Stretching Vibration Bands

υsCN―υas

CN at 2180 and 2200 cm-1

malononitrile

1a containing malononitrile

1a containing ethyl cyanoacetate

1a containing cyano-acetic acid tert-butyl ester

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Table 2. Knoevenagel Condensation Reaction of Benzla

ldehyde with Substrates, Catalyzed by 1a

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Conversion (%) vs Time (h) for Knoevenagel Condensation Reactions

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Conclusion

• This work describes the construction of a 3D PCP containing guest-accessible amide groups and characterizes the selective inclusion of guest molecules with the structural transformation of the host 。

• We observed selective guest inclusion via the hydrogen bond, which is based on not only the size and shape of the incoming guest but also its affinity for the amide group.

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• As a result, the Knoevenagel condensation reaction, which is a well-known base-catalyzed model reaction, was selectively promoted in good yield 。

• This research is particularly relevant in the context of porous solid-state chemistry in the generation of new materials with FOS 。