Selective Intercalation of Various Muconates into

Selective Intercalation of Various Muconates into [LiAl2(OH)6]ClH2O Layered Double Hydroxide (LDH) 이석우, 정덕영* 성균관대학교화학과-BK21 jisanrhee@hanmail.net dyjung@chem.skku.ac.kr 031-290-5974 (tel) 031-290-7075 (fax)

Abstract The LDHs intercalated with (Z,Z)- and (E,E)-muconates, [LiAl2(OH)6]2[C6H4O4]nH2O were synthesized by the reaction of [LiAl2(OH)6]ClH2O with aqueous muconates solution. The properties of LDHs were investigated by the XRPD, FT-IR, SEM, TGA and 1H NMR. The XRPD analyses show that [LiAl2(OH)6]2[(Z,Z)-C6H4O4]nH2O and [LiAl2(OH)6]2[(E,E)-C6H4O4]nH2O gave different basal spacings after intercalation and the metastable phases exist in the case of [LiAl2(OH)6]2 [(Z,Z)-C6H4O4]nH2O.Furthermore, it was found that (E,E)-muconate presents high selectivity in the intercalation reaction into the [LiAl2(OH)6]ClH2O from the mixture of (Z,Z)- and (E,E)-muconate isomers.

Muconic Acids Muconic acid: 2,4-hexadienedioic acid (Z,Z)-form: Polyester Precursor of adipic acid: polyamides Crystal engineering of polymuconic acid (E,E)-form: Urinary metabolite of benzene metabolism Biological marker of occupational and environmental exposure of benzene

Experimental Sections ref) Chem. Mater. 1997, 9, 241 & 1998, 10, 351 1. Synthesis of [LiAl2(OH)6]ClyH2O [LiAl2(OH)6]ClyH2O 2Al(OH)3(s) + LiCl(aq) H2O, reflux 2. Synthesis of LDHs Intercalated with (Z,Z)- and (E,E)-muconates 2[LiAl2(OH)6]Cl + (Z,Z)-C6H4O42- [LiAl2(OH)6]2[(Z,Z)-C6H4O4] + 2Cl- 2[LiAl2(OH)6]Cl + (E,E)-C6H4O42- [LiAl2(OH)6]2[(E,E)-C6H4O4] + 2Cl- 3. Competitive Intercalation Reaction of (Z,Z)- and (E,E)-muconates [LiAl2(OH)6]2[(Z,Z)-C6H4O4] + (E,E)-C6H4O42- K [LiAl2(OH)6]2[(E,E)-C6H4O4] + (Z,Z)-C6H4O42-

Chemical Analyses and Physical Techniques 4. Thermogravimetric Analyses: - under air flow of 10 cm3 min-1 - on a TGA 2960 of TA instrument - with the heating rate of 10.0 oC min-1 -in the range rt - 1000 oC 5. 1H NMR Spectra: - Varian 500 spectrometer - at 20 oC - chemical shifts (d) against TMS - D2O 1. Elemental Analyses: - C, N, H: EA 1110 elemental analyzer of CE Instrument - metals: ICPS-1000IV analyzer of Shimadzu - chloride: chloride ion-selective electrode of Istek combined electrode. 2. X-ray Powder Diffraction: - a MAC Science 18XMF diffractometer - using Cu Ka1 radiation (1.54056 Å) - with a graphite monochromater - at a rate 2q = 15 o min-1 - with a range 2q = 3.5 - 80 o 3. FT-IR Spectra: - Nicolet 205 FT-IR spectrometer - on KBr pellets - in the range of 4000 - 400 cm-1 - resolution was 2 cm-1, 16 scans

X-ray Powder Diffraction Patterns of LDHs (a) [LiAl2(OH)6]ClyH2O (b) wet and (c) dried [LiAl2(OH)6]2[(Z,Z)-C6H4O4]zH2O (d) wet and (e) dried [LiAl2(OH)6]2[(E,E)-C6H4O4]zH2O

dLT dHB dIL dHB 14.06 Å Schematic Diagrams for LDHs Intercalated with Muconates dLT dHB dIL dHB 13.07 Å [LiAl2(OH)6]2[(E,E)-C6H4O4]zH2O [LiAl2(OH)6]2[(Z,Z)-C6H4O4]zH2O

FT-IR and Thermal Analysis of LDHs FT-IR Spectra TGA Profiles (a) [LiAl2(OH)6]ClyH2O, (b) [LiAl2(OH)6]2[(Z,Z)-C6H4O4]zH2O, (c) [LiAl2(OH)6]2[(E,E)-C6H4O4]zH2O

SEM Image of LDHs

6 Schematic Diagrams for Selective Intercalation of Muconates Cl Cl Cl 6 + 6 Cl Cl Cl Cl Cl Cl Cl Cl Cl 12 Cl-

Spectroscopic Analysis of LDHs Intercalated with Mixed Muconates XRPD Patterns 1H NMR Spectra (E,E)0/(Z,Z)0 0/100 25/75 50/50 75/25 100/0 starting solution: 35 mL, [LiAl2(OH)6]ClyH2O: 2.52 mmol, total muconates: 3.02 mmol

Shape-selective Intercalation of Muconates into [LiAl2(OH)6]+ Lattice Extreme Models for the Intercalation Reaction from Aqueous Isomeric Mixture of Muconates 1) exclusive intercalation of (Z,Z)-muconate 2) intercalation of two isomer with same affinity 3) exclusive intercalation of (E,E)-muconate. a(E,E)vs. x(E,E),0 Plot - a(E,E), mole fraction of (E,E) in the interlayer - x(E,E),0, mole fraction of initial (E,E) in the sol’n. - experimental data(◆) - [LiAl2(OH)6]ClyH2O: 2.52 mmol - total muconates: 3.02 mmol - aqueous sol’n: 35 mL

Thermodynamic Approach to Shape-selective Intercalation Apparent Partition Constant K' log K' vs. a(E,E) Plot [LiAl2(OH)6]2[(Z,Z)-C6H4O4] + (E,E)-C6H4O42- K [LiAl2(OH)6]2[(E,E)-C6H4O4] + (Z,Z)-C6H4O42- K = 3.73 [[LiAl2(OH)6]2[(E,E)-C6H4O4]]eq[(Z,Z)-C6H4O42-]eq K' = [[LiAl2(OH)6]2[(Z,Z)-C6H4O4]]eq[(E,E)-C6H4O42-]eq Thermodynamic Equilibrium Constant K

[LiAl2(OH)6]ClyH2O [LiAl2(OH)6]2[(E,E)-C6H4O4]zH2O (E,E)-muconate (Z,Z)-muconate Schematic Diagrams for Selective Intercalation of Muconates N2 separation + rt, 2 h

Conclusion Layer-structured Materials Intercalated with Muconates were Synthesied [LiAl2(OH)6]2[(Z,Z)-C6H4O4]zH2O [LiAl2(OH)6]2[(E,E)-C6H4O4]zH2O. Shape-selective Intercalation with Isomeric Mixtures of Muconates is thermodynamically controlled competitive reaction. depends on the mole fractions of muconates in both solid and sol’n. could explained with apparent partition constant K’. has its thermodynamic equilibrium constant K of 3.73. , it is clear that the shape of dicarboxylate anion plays a key role in the determining the selectivity for the host lattice because it induces different interaction between anions and positive layers.

Future Work Future Works , effects of concentration of [LiAl2(OH)6]ClyH2O and muconates, reaction temperature, solvent, and atmospheric conditions are under investigation. Acknowledgements.This work was supported by Korea Foundation Grant (KRF-2000-031-000). Rhee, S. W. also acknowledge KRF for BK-21 fellowship.

Selective Intercalation of Various Muconates into