Disproportionation of an Element in a Zeolite. III. Crystal Structure of a

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C: Surfaces, Interfaces, Porous Materials, and Catalysis

Disproportionation of an Element in a Zeolite. III. Crystal Structure of a High Temperature Sulfur Sorption Complex of Zeolite LTA Containing Two New Ions: Perthiosulfite, S , and the Trisulfur Cation, S 42-

32+

Hyeon Seung Lim, Nam Ho Heo, and Karl Seff J. Phys. Chem. C, Just Accepted Manuscript • DOI: 10.1021/acs.jpcc.8b09223 • Publication Date (Web): 16 Nov 2018 Downloaded from http://pubs.acs.org on November 29, 2018

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The Journal of Physical Chemistry

Disproportionation of an Element in a Zeolite. III. Crystal Structure of a High Temperature Sulfur Sorption Complex of Zeolite LTA Containing Two New Ions: Perthiosulfite, S42-, and the Trisulfur Cation, S32+

Hyeon Seung Lim,† Nam Ho Heo,†,* and Karl Seff §

†Laboratory

of Structural Chemistry,

School of Applied Chemical Engineering, Kyungpook National University, Daegu 41566, Korea

§Department

of Chemistry, University of Hawaii,

2545 The Mall, Honolulu, Hawaii 96822, United States

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(abstract) The structure of a high temperature sulfur sorption complex of zeolite Na-A (LTA) has been determined by single-crystal crystallography. with sulfur vapor at 623 K.

It was prepared by treating anhydrous Na-A

Its crystal structure was refined in the space group Pm 3 m (a =

12.192(1) Å) to the error index R1 = 0.075.

Upon sorption, sulfur disproportionated fully

to give one perthiosulfite anion, S42-, and one trisulfur cation, S32+, per unit cell.

The

perthiosulfite anion (S-S = 2.16(5) Å and S-S-S = 105.4(22)˚) is the perthio form of SO32-. It is in the large cavity where it bonds to one 6-ring and three 8-ring Na+ ions (S-Na = 2.83(6) Å, 2.80(5) Å, and 2.43(5) Å). polysulfide ion.

It appears to be the first example of a branched

The electron deficient trisulfur cation, S32+ (S-S = 2.11(8) Å and S-S-S =

102.0(14)˚), bonds to framework oxygen atoms in the sodalite cavity (S-O = 2.64(7) Å). Twelve Na+ ions are found per unit cell at five crystallographic sites similar to but different from those in anhydrous Na-A.

Eleven are near 6- and 8-rings, and the twelfth lies

opposite a 4-ring in the sodalite cavity.

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1. INTRODUCTION Elements have been observed to disproportionate electronically into cations and anions upon sorption into zeolites.1,2

Because anhydrous polar zeolites are polar media, this is

akin to the dissociation of salts when they dissolve in polar solvents.

Perhaps NO, an odd

molecule, disproportionates into NO+ and NO- upon sorption into polar zeolites.3

Zeolites

A (LTA) and X (FAU) are examples of polar zeolites; they have very anionic frameworks due to their high aluminum contents and a large number of exchangeable cations, needed to balance that negative charge. The disproportionation of two elements, iodine and sulfur, has been reported upon sorption into anhydrous fully Cd2+-exchanged zeolite X, Cd46-X; Cd46Si100Al92O384 is its unit cell formula.1,2

Upon sulfur sorption, S2- ions coordinated to Cd2+, and tetrahedral S44+

and n-S42+ were found.1 I5- were seen.2

When this experiment was repeated using iodine, cyclo-I42+ and n-

Here we report a third example of the disproportionation of an element

upon sorption into a zeolite, sulfur sorbed at a high temperature into anhydrous zeolite A. This work was undertaken simply to find the twelfth Na+ ion in a sulfur sorption complex of Na12-A; Na12Si12Al12O48 is its unit cell formula.

Its structure, reported in 1972,

was found to contain two S8 rings per unit cell, but only 11 Na+ ions could be found.4 Now, with the availability of higher quality diffraction data, we wished to find that twelfth ion.

We anticipated that it would be at the center of the large cavity, sandwiched between

two parallel (non-planar) S8 rings.



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Anaerobic bacteria are able to disproportionate elemental sulfur in the presence of water and a third material such as FeOOH, FeCO3, MnCO3, or MnO2.5-11

2. EXPERIMENTAL SECTION Large single crystals, clear colorless cubes, of Na-A (|Na12(H2O)x|[Si12Al12O48]–LTA, Na12–A·xH2O, or Na12–A) were synthesized by J. F. Charnell12 in G. T. Kokotailo’s laboratory.

One of these crystals was loaded into a fine Pyrex capillary.

2.1. Reaction with Sulfur.

A tube of sulfur flakes (Sigma-Aldrich, 99.998%) was

attached as a side arm to a Pyrex reaction vessel.

Another arm to this vessel ended with

the capillary containing the hydrated Na-A crystal.

The complete vessel was then attached

to a vacuum line for dehydration.

After the zeolite crystal was dehydrated under vacuum

at 623 K, the temperature of the sulfur-containing side arm was increased to 623 K also. Using heating tape, the remaining parts of the reaction vessel were heated to 423 K.

After

the reaction vessel and all of its contents were fully dehydrated, it was sealed off under vacuum from the line.

The sulfur was sublimed to the tube above the capillary, and the

remainder of the reaction vessel was sealed off and discarded. then heated to 543 K for 72 h to allow sorption to occur. another 48 h.

The crystal and sulfur were

This was continued at 373 K for

To eliminate any unreacted sulfur in or near the crystal and to further allow

the sulfur in the zeolite to come to equilibrium, only the end of the capillary containing the


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product crystal was maintained at 333 K for an additional 24 h.

Finally, after the vessel

had cooled, the product crystal was sealed off in its capillary under vacuum by using a small torch.

The crystal was now pale yellow.

The complete sample preparation conditions are

presented in Table 1. It is now believed that the disproportionation reaction occurred before the crystal and the sulfur was maintained at 543 K for 72 h.

Previous work had shown that treatment at

543 K and subsequent lower temperatures did not produce disproportionation; instead an octasulfur sorption complex was seen.4

It appears that the disproportionation reaction

occurred at 623 K as the crystal and the sulfur were being dehydrated. able to reach the crystal during that step.

S (g, 20 Pa) was

(The vapor pressure of sulfur at the lowest

temperature, 423 K, inside the vessel is 20 Pa.)

See the second paragraph of section 5 for

more discussion. 2.2. X-Ray Diffraction.

As previously described,13,14 synchrotron X-ray diffraction

intensities for the single crystal were measured by the omega scan method at the Photon Factory (PF), Tskuba, Japan.

The space group Pm 3 m, appropriate for zeolite A unless

high precision is achievable, was used.

The crystallographic data and statistics are

summarized in Table 2.

3. STRUCTURE DETERMINATION



Full-matrix least-squares refinements were carried out on F2 with all 726 unique reflections using SHELXL201415 (Table 2).

They were started with fixed weights and the

atomic parameters of the framework atoms [T(Si,Al), O1, O2, and O3] in dehydrated Na12A.

The initial refinements of the framework atoms with their anisotropic thermal

parameters converged to the high error indices (defined in footnotes to Table 2) R1 = 0.21 and R2 = 0.55 (Table 3, step 1).

The further steps of structure determination as subsequent

peaks in difference Fourier functions were included as extraframework atoms are tabulated in Table 3.

The final weights were assigned using the formula w = 1/[σ2(Fo2) + (aP)2 + bP]

where P = [max(Fo2,0) + 2Fc2]/3; a and b were refined parameters (Table 2). 3.1. Na+ Ions.

Early in structure refinement, the number of Na+ ions at Na2 refined to

5.3(3) ions per unit cell.

The maximum occupancy at this position is three, so this

indicates that the 8-rings are fully occupied. (Table 3, step 6).

This occupancy, therefore, was fixed at 3.0

After that, the sum of the occupancies of all 6-ring cations, Na10, Na11,

and Na12, insignificantly exceeded the capacity of the 6-rings, indicating that these rings are also completely occupied. was imposed. (step 11).

A constraint for full 6-ring occupancy, 8.0 ions per unit cell,

Because only one additional Na+ ion is needed to complete the

placement of the 12 Na+ ions per unit cell, and considering its esd, the occupancy at Na3 was fixed at 1.0 (step 16). 3.2. Perthiosulfite Anion, S42-.

In step 11, 0.23(9) and 0.59(21) sulfur atoms were


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found per unit cell at S1 and S2, respectively, in the large cavity.

Because S1 was on a

threefold axis with an acceptable bonding distance to S2, and the occupancy ratio S1/S2 was 2.6(14), the occupancy at S2 was constrained to be three times that at S1. cluster of four sulfur atoms with threefold symmetry.

This gives a

Each atom at S2 bonds tightly to an

8-ring Na+ ion at Na2 (S2-Na2 = 2.43(5) Å), indicating that this S4 cluster has a negative charge.

A simple application of the octet rule to this cluster gives a formal charge of 1- at

S2, 1+ at S1, and a total charge of 2-: hence S42-.

Because the occupancy at S2 was nearly

three and there are three Na+ ions at Na2, the occupancies at S2 and S1 were fixed at 3.0 and 1.0, respectively (step 15).

Similarly, the occupancy at Na10 was fixed at 1.0.

Altogether, the occupancies at Na10, S1, S2, and Na2 were fixed at 1, 1, 3, and 3 per unit cell (step 15). 3.3. Trisulfur Cation, S32+.

In step 14, 0.14(5) and 1.9(3) sulfur atoms were found per

unit cell at S3 and S4, respectively, in the sodalite cavity.

Although the occupancy at S3

refined consistently to a value of marginal significance (Table 3), it consistently reappeared, unignorable, as the largest peak by far on difference Fourier functions whenever it was removed from refinement.

S3 was located at the center of the sodalite cavity with an

acceptable bonding distance to S4.

Among their equipositions, two S4 positions are

selected to give a typical bent S-S-S angle.

Each atom at S4 bonds to two framework

oxygen atoms (S4-O3 = 2.64(7) Å), indicating that this three atom group is positively charged.

After placing an octet of electrons about S3 and four more about each S4 atom, it 7 ACS Paragon Plus Environment


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became clear that this group is electron deficient, that each sulfur atom at S4 has a formal 1+ charge, that this trisulfur cluster is S32+, and that each terminal atom (S4) is acting as a Lewis acid, accepting electron pair density from two framework O3 oxygen atoms to complete its octet. The two S4 positions about S3 could have been chosen to give a linear S32+ unit. structure was not selected for the following reasons.

That

It would have two S=S double bonds

about S3; such bonding is not documented in the chemical literature.

The formal charge at

S3 would be 2+, and it would be zero at the S4 positions, a more extreme separation of charge than appears with the bent structure.

Finally, those charges would be incompatible

with the environment of the S32+ group, which bonds to the anionic oxygen atoms of the zeolite framework with its S4 atoms, not S3. 3.4. Sulfur Cluster Occupancies.

Because S42- has a 2- charge, and S32+ is 2+, their

occupancies must be equal for charge neutrality.

Accordingly the occupancies at S3 and

S4 were fixed at 1.0 and 2.0, respectively (Table 3, steps 17 and 19, and Table 6). 3.5. S3 Position.

S3 should not be at (0,0,0) because the symmetry of its environment

is far less than the symmetry at this special position.

Therefore careful refinements were

done at the three symmetry positions, (0,0,z), (0,y,y), and (x,y,z), that would allow the two S3-S4 distances to remain equal. center of sodalite cavity.

All failed, so S3 was allowed to remain at (0,0,0), at the

The resulting geometry, an S3-S4 bond length of 2.11(8) Å and


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an S4-S3-S4 angle of 102.0(14)˚, was reasonable. 3.6. Final Occupancies.

With the occupancies of other atoms fixed at integers, the

occupancies at Na11 and Na12 converged to 4.31(13) and 2.69(13), respectively, so these were also fixed at integers (step 18).

The final occupancies, all integers, and the total

charge budget for the extraframework cations are presented in Table 6. 3.7. Other Crystallographic Details.

The final structural parameters are presented in

Table 4, and selected interatomic distances and angles are given in Table 5.

The atomic

scattering factors, modified for anomalous dispersion,16,17 were those of neutral atoms. See Table 2 for additional details.

4. STRUCTURE DESCRIPTION 4.1. Framework Geometry.

The mean T-O bond length, 1.659 Å, is about the same

as the mean (1.675 Å) of the Si4+-O (1.61 Å) and Al3+-O (1.74 Å) bonds reported in both hydrated Na-A18 and dehydrated Ca-LSX.19

As is often observed, T-O3, 1.6696(12) Å, is

somewhat longer than T-O1, 1.6483(17) Å, and T-O2, 1.6469(12) Å (Table 5).

This is

because most of the non-framework cations, including S32+, coordinate to O3 atoms (Table 5).13,20,21

For the same reason, the T-O3-T angle is the smallest (Table 5).

4.2. Extraframework Ions. 4.2.1. Na+.

The negative framework of zeolite LTA is fully balanced by twelve Na+



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ions per unit cell; these were present in the starting zeolite, Na12-A. opposite 6-rings, three on 8-rings, and one near a 4-ring.

Eight are located

The eight 6-ring Na+ ions are

found at three crystallographically distinct positions, Na10, Na11, and Na12.

Na10 and

Na11 are in the large cavity and Na12 is in the sodalite cavity (Figures 2 and 4).

Each Na+

ion bonds to three O3 oxygen atoms of its 6-ring at 2.380(9), 2.334(8), and 2.248(4) Å, respectively.

The Na+ ions at Na2 lie on 8-rings in the large cavities.

O1 at 2.18(4) Å and one O2 atom at 2.35(4) Å.

Each bonds to one

All of these Na-O bond lengths (Table 5)

are close to the sum of the corresponding ionic radii, 2.29 Å.22

Finally, the Na+ ion at

Na10 bonds to all four atoms of the perthiosulfite group while the three at Na2 each bond to an S2 atom (Figure 1). The remaining Na+ ion, the 12th, is at Na3, opposite a 4-ring in the sodalite cavity. Each coordinates to four framework oxygen atoms at 2.79(4) Å, substantially longer than the sum of their ionic radii.

One reason why this distance should be inaccurate is that the

O3 position surely represents the majority of the 4-rings, not the one per unit cell that hosts Na3. 4.2.2. Perthiosulfite Anion, S42-.

A perthiosulfite ion, like the sulfite ion, SO32-, but

with all atoms sulfur, occupies each large cavity (Figures 1 and 2).

The S1-S2 bond,

2.16(5) Å, agrees with that in S8(s), 2.046(3) Å,23 and the S2-S1-S2 angle, 105.4(22)˚, agrees with the O-S-O angle, 105.69(17)˚, in SO32S8(s).23

24

and the S-S-S angle, 108.2(6)˚, in

The S-S bond in S42- is appropriately longer than the S-O bond in SO32- (Table 7). 10 ACS Paragon Plus Environment

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The perthiosulfite ion wraps itself part way around the Na+ ion at Na10; all four of its atoms bond to Na10, S1-Na10 = 2.83(6) Å and S2-Na10 = 2.80(5) Å (see Figure 1). addition, each atom at S2 bonds to a Na+ ion at Na2 at 2.43(5) Å (Figures 1 and 2).

In The

S1-Na10 and S2-Na10 distances are both the same as the sum of the corresponding van der Waals radius of sulfur and ionic radius of Na+,22 1.85 + 0.97 = 2.82 Å.

Because S2 is more

negative than S1 (its formal charge is 1- (section 3.2)), S2-Na2, 2.43(5) Å, is appropriately much shorter than S1-Na10. 4.2.3. Trisulfur Cation, S32+. 3 and 4).

A trisulfur cation occupies each sodalite cavity (Figures

The S3-S4 bond length, 2.11(8) Å, agrees well with the S-S distances mentioned

above,1,4,23,25 and the S4-S3-S4 angle, 102.0(14)˚, is similar to that in the perthiosulfite ion, 104(3)˚, and in S8(s),23 108.2(6)˚. The two sulfur atoms at S4 approach framework O3 oxygen atoms at 2.64(7) Å.

This

agrees with the S-O bond length, 2.58(8) Å, observed for the two terminal sulfur atoms in nS42+ in Cd-X.1

As described in section 3.3, S32+ is electron deficient, as was n-S42+.

Lone

pair electron density from oxygen atoms at O3 acts to complete the octet of electrons about each sulfur atom at S4. The thermal motion at S3 is unusually high.

One reason for this is that it is free to

wag to some degree, but it should be artificially elevated because S3 should not be at (0,0,0) (section 3.5), only near there.



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5. DISCUSSION Elemental sulfur disproportionated electronically upon sorption into anhydrous Na12-A at 623 K.

The net reaction per unit cell is 7S → S42- + S32+

(1)

A mixture of sulfur species is present in the vapor phase at that temperature; S2, S3, and S4 should easily be able to enter the zeolite structure.

The reaction proceeded until the

sodalite cavities (one per unit cell) became full with S32+ (Figure 4). Less definitively it can be said that the large cavities (also one per unit cell) became filled.

Although there is room in the large cavity for more S42- (Figure 2), the three 8-ring

Na+ ions per unit cell already bond to S42-; more than one S42- per large cavity would require that they bridge between S42- ions.

Of course the number of S42- cannot exceed the number

of S32+ (reaction 1), so there cannot be more than one in each large cavity. In sharp contrast, our previous report of the reaction between anhydrous Na12-A and sulfur showed only sorption;4 two S8 rings filled each large cavity; sulfur had not disproportionated at all.

Although we were trying to reproduce our original experimental

conditions, the experimental setup was different.

This time there was a point during

crystal preparation when the sulfur was being heated under vacuum to 623 K to dry it as it sublimed out of its side arm. 378 K (Table 1).

This temperature is substantially higher than was used before,

During that step, the crystal was at 623 K and all other regions of the

reaction vessel, under dynamic vacuum with external heating tape to dry them, were at 12 ACS Paragon Plus Environment

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about 423 K.

S(g), then, at a vapor pressure of 20 Pa, could flow to the crystal at 623 K

and react with it.

Thus the subsequent steps labeled “reaction with S(g)” in Table 1, done

at 543 K or less, appear to be unimportant because the disproportionation had apparently already occurred at 623 K.

Note that the reaction temperature for the disproportionation of

sulfur on Cd46-X, 603 K, was also relatively high.1

It is clear that, although sorption may

occur at lower temperatures, disproportionation requires higher temperatures to overcome a barrier. The barrier to disproportionation appears to be kinetic rather than thermodynamic.

A

complete array of simple ionic and dative ionic bonds are present in the disproportionation structure, whereas the simple sorption structure had only weak ion-to-induced-dipole bonding.

Thus the disproportionation product should be at a substantially lower energy

and should be favored thermodynamically.

Indeed, the rearrangement from S8 to S42- and

S32+ requires ionization, suggesting that the kinetic barrier could well be high. The products of the disproportionation of sulfur on Cd46-X were tetrahedral S44+, n-S42+, and S2-.1

With Na12-A, the products are quite different, S32+ and S42-.

similarity, however.

There is a point of

The cations n-S42+ in Cd46-X and S32+ here are both electron deficient

and act as Lewis acids, approaching oxide ions of the zeolite framework to complete their octets of electrons.

Clearly, the products of the disproportionation depend on the

exchangeable cation (with S2-, 3-coordinate Cd2+ formed a new strong bond as it became 4coordinate1), and they should also depend on the topology of the zeolite. 13 ACS Paragon Plus Environment


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The perthiosulfite ion is a structural isomer of the n-tetrasulfide anion, n-S42-, topologically like isobutane is an isomer of n-butane.

It may be viewed as a branched

polysulfide. Branching had not been seen before in polysulfides, although it occurs readily in polysulfur cations.26 The Na+ ions have rearranged themselves substantially to accommodate the products of the disproportionation, predominantly to coordinate to and stabilize the perthiosulfite ion. Although there was only one position for the eight 6-ring Na+ ions in dehydrated Na12-A,27 there are three in this structure (Tables 4 and 8).

Among these eight, one (Na10) has

moved substantially, 0.55(3) Å, into the large cavity to bond to all four atoms of the perthiosulfite ion.

Similarly, the 8-ring Na+ ions have moved to a position of lower

symmetry, from (0,0.43,0.43) in dehydrated Na12-A to (0,0.40,0.46) to bond to S2 (Table 8). The remaining seven 6-ring Na+ ions occupy two positions (Na11 and Na12) rather than one, perhaps in part because some 6-ring O3 atoms have bonded to S32+.

Finally, the twelfth

Na+ ion per unit cell (Na3), which was in the large cavity in anhydrous Na12-A, is in the sodalite cavity. The Na3-S3 distance, Na3-S3 = 2.09(5) Å, is too short to be believed.

One reason is

that the S3 position must only be approximate (section 3.5).

Another is that Na3 is a low-

occupancy position and therefore less precisely determined.

Both Na3 and S3 could be

displaced from their positions of high symmetry to increase this distance. The primary driving force for reaction 1 appears to be the formation of ionic bonds 14 ACS Paragon Plus Environment

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between Na+ and anionic sulfur.

The structure of the zeolite has allowed some Na+ ions to

be in positions where they could bond to all four atoms of a perthiosulfite ion.

In this

process, some Na+ ions were able to increase their coordination numbers to values more commonly seen and to improve their coordination geometries.

The positions of the Na+

ions in another zeolite might favor the formation of a different polysulfide anion.

S32+

appears to be more of a by-product of the reaction, contributing less to the energetics, as S44+ and n-S42+ had been.1

6. CONCLUSIONS Sulfur has disproportionated within Na12-A at 623 K to give two new polyatomic ions of sulfur, S42- with the geometry of the sulfite ion and bent S32+. a S42- anion and each sodalite cavity contains a S32+ cation.

Each large cavity contains Disproportionation did not

occur when the reaction was performed at a somewhat lower temperature, 573 K, indicating that this disproportionation has a kinetic barrier.

S42-, the perthiosulfite ion, appears to be

the first example of a branched polysulfide ion.

■ ASSOCIATED CONTENT Supporting Information



The supporting Information is available free of charge on the ACS Publications website at DOI: Observed and calculated structure factors squared with esds.

■ AUTHOR INFORMATION Corresponding Author * Tel.: +82 53 950 5589; Fax: +82 53 950 6594; E-mail address: [email protected]

■ ACKNOWLEDGEMENTS We gratefully acknowledge the Photon Factory, Tsukuba, Japan for the use of their synchrotron, diffractometer, and computing facilities.

This work was supported by a

National Research Foundation of Korea (NRF) Grant NRF-2017R1E1A1A01074837 funded by the Korean government (MSTI)


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■ REFERENCES (1) Song, M. K.; Kim, Y.; Seff, K. Disproportionation of an Element in a Zeolite. I. Crystal Structure of a Sulfur Sorption Complex of Dehydrated, Fully Cd2+-Exchanged Zeolite X. Synthesis of Tetrahedral S44+ and n-S42+, Two New Polyatomic Cations of Sulfur. J. Phys. Chem. B 2003, 107, 3117-3123. (2) Song, M. K.; Choi, E. Y.; Kim, Y.; Seff, K. Disproportionation of an Element in a Zeolite. II. Crystal Structure of an Iodine Sorption Complex of Dehydrated Fully Cd2+Exchanged Zeolite X Containing n-I5-as I-−I3+−I- and Square cyclo-I42+. J. Phys. Chem. B 2003, 107, 10709-10714. (3) Chao, C.-C.; Lunsford, J. H. Adsorption of Nitric Oxide on Y-type Zeolites. LowTemperature Infrared Study. J. Am. Chem. Soc. 1971, 93, 6794-6800. (4) Seff, K. Crystal Structure of a Sulfur Sorption Complex of Zeolite 4A. J. Phys. Chem. C 1972, 76, 2601-2605. (5) Finster, K. Microbiological Disproportionation of Inorganic Sulfur Compounds. J. Sulfur Chem. 2008, 29, 281-292. (6) Böttcher, M. E.; Thamdrup, B.; Vennemann, T. W. Oxygen and Sulfur Isotope Fractionation during Anaerobic Bacterial Disproportionation of Elemental Sulfur. Geochim. Cosmochim. Acta 2001, 65, 1601-1609. (7) Janssen, P. H.; Schuhmann, A.; Bak, F.; Liesack, W. Disproportionation of Inorganic Sulfur Compounds by the Sulfate-Reducing Bacterium Desulfocapsa Thiozymogenes gen. nov., sp. nov. Arch. Microbiol. 1996, 166, 184-192. (8) Canfield, D. E.; Thamdrup, B. The Production of 34S-Depleted Sulfide during Bacterial Disproportionation of Elemental Sulfur. Science 1994, 266, 1973-1975. (9) Finster, K.; Liesack, W.; Thamdrup, B. Elemental Sulfur and Thiosulfate Disproportionation by Desulfocapsa Sulfoexigens sp. nov., a New Anaerobic Bacterium Isolated from Marine Surface Sediment. Appl. Environ. Microbiol. 1998, 64, 119-125. (10) Böttcher, M. E.; Thamdrup, B. Anaerobic Sulfide Oxidation and Stable Isotope Fractionation Associated with Bacterial Sulfur Disproportionation in the Presence of MnO2. Geochim. Cosmochim. Acta 2001, 65, 1573-1581. (11) Thamdrup, B.; Finster, K.; Hansen, J. W.; Bak, F. Bacterial Disproportionation of Elemental Sulfur Coupled to Chemical Reduction of Iron or Manganese. Appl. Environ. Microbiol. 1993, 59, 101-108. (12) Charnell, J. F. Gel Growth of Large Crystals of Sodium A and Sodium X Zeolites. J. Cryst. Growth 1971, 8, 291-294. (13) Nsanzimana, J. M. V.; Kim, C. W.; Heo, N. H.; Seff, K. Using the Thallous Ion Exchange Method to Exchange Tin into High Alumina Zeolites. 1. Crystal Structure of |(Sn2+)5.3 (Sn4+)0.8 (Cl–)1.8|[Si12 Al12 O48]-LTA. J. Phys. Chem. C 2015, 119, 3244-3252. (14) Kim, J. Y.; Park, J. M.; Kim, H. J.; Heo, N. H.; Seff, K. Exchange of a Tetrapositive Cation into a Zeolite and a New Inorganic Scintillator. I. Crystal Structures and Scintillation Properties of Anhydrous Zr1.7Tl5.4Cl1.7–LTA and Zr2.1Tl1.6Cl3.0–LTA. J. Phys. Chem. C 2015, 119, 18326-18339. (15) Sheldrick, G. M. A Short History of SHELX. Acta Crystallogr., Sect. A 2008, 64, 112122. (16) Cromer, D. T. Anomalous Dispersion Corrections Computed from Self-Consistent Field Relativistic Dirac-Slater Wave Functions. Acta Crystallogr. 1965, 18, 17-23. (17) Moss, D. S. International Tables for X-ray Crystallography, Vol. IV; Kynoch Press: Birmingham, U.K., 1974; p 148. (18) Fischer, R. X.; Sehovic, M.; Baur, W. H.; Paulmann, C.; Gesing, T. M. Crystal Structure and Morphology of Fully Hydrated Zeolite Na-A. Z. Kristallogr. 2012, 227, 438-445. 17 ACS Paragon Plus Environment


(19) Vitale, G.; Bull, L. M.; Morris, R. E.; Cheetham, A. K.; Toby, B. H.; Coe, C. G.; Mac Dougall, J. E. Combined Neutron and X-ray Powder Diffraction Study of Zeolite Ca LSX and a 2H NMR Study of Its Complex with Benzene. J. Phys. Chem. 1995, 99, 16087-16092. (20) Pluth, J. J.; Smith, J. V. Crystal Structure of Dehydrated Ca-Exchanged Zeolite A. Absence of Near-Zero-Coordinate Ca2+ ion. Presence of Al Complex. J. Am. Chem. Soc. 1983, 105, 1192-1195. (21) Riley, P. E.; Seff, K. Crystal Structures of Dehydrated Partially Cobalt(II)-Exchanged Zeolite A and of Its Carbon Monoxide Adduct. Inorg. Chem. 1974, 13, 1355-1360. (22) Weast, R. C. Handbook of Chemistry and Physics, 64th ed; CRC Press: Cleveland, OH 1983; p F-170. (23) Steudel, R. Elemental Sulfur and Sulfur-Rich Compounds I; Springer Science & Business Media, Berlin, 2003; p 23. (24) Larsson, L. O.; Kierkegaard, P. The Crystal Structure of Sodium Sulphite. Acta Chem. Scand. 1969, 23, 2253-2260. (25) Meyer, B. Elemental Sulfur. Chem. Rev. 1976, 76, 367-388. (26) Engesser, T. A.; Krossing, I. Recent Advances in the Syntheses of Homopolyatomic Cations of the Non Metallic Elements C, N, P, S, Cl, Br, I and Xe. Coord. Chem. Rev. 2013, 257, 946-955. (27) Yanagida, R. Y.; Amaro, A. A.; Seff, K. Redetermination of the Crystal Structure of Dehydrated Zeolite 4A. J. Phys. Chem. 1973, 77, 805-809.


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Table 1. Sample Preparation Conditions treatment ref. 1a ref. 4b this reportb T (K) 723 623 623 t (h) 48 24 48 crystal dehydration -4 -4 P (Pa) 2.7 x 10 8.0 x 10 1.5 x 10-4 T (K) 293 378 623c drying of sulfur t (h) 96 24 48 (vacuum sublimation) P (Pa) 1.5 x 10-4 8.0 x 10-4 1.5 x 10-4 T (K) 523 573 543 step 1 t (h) 24 100 72 reaction with S(g) T (K) 603 543 373 step 2 t (h) 72 240 48 T (K) 523 388 333 distillationd t (h) 24 90 24 yellow bright yellow pale yellow crystal color aSulfur disproportionated upon sorption into Cd-X. bSulfur sorbed onto c Na-A at 573 K did not disproportionate. It appears that reaction occurred during this step at 623 K. dThis step was done to remove any weakly held sulfur that might be in the crystal, to remove any S(s) on or near the crystal that would later be in the X-ray beam, and to allow more time, if needed, for the product crystal to come to equilibrium. Only the part of the reaction vessel containing the crystal was maintained at these temperatures; the more distant parts were at ambient temperature.



Table 2. Crystallographic Data X-ray source PF(BL-5A)a wavelength (Å) 0.7500 detector ADSC Quantum-315r crystal-to-detector distance (mm) 60 data collection temperature (T (K)) 294(1) space group, No. Pm3m, 221 unit cell constant, a (Å) 12.192(1) maximum 2θ for data collection (deg) 73.00 no. of reflections measured 37,082 no. of unique reflections measured, m 726 no. of reflections with Fo > 4σ(Fo) 679 no. of variables, s 47 data/parameter ratio, m/s 15.4 weighting parameters: a, b 0.1637, 0.44 Final error indices: R1b, R1*c, R2d 0.075, 0.097, 0.239 e Goodness of fit 1.29 aBeamline BL-5A at PF, Japan. bR = |F - |F ||/F ; R is 1 o c o 1 calculated using those reflections for which Fo > 4(Fo). cR1* is calculated using all unique reflections measured. dR2 = [w(Fo2Fc2)2/w(Fo2)2]1/2 is calculated using all unique reflections measured. eGoodness of fit = (w(Fo2-Fc2)2/(m-s))1/2.


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Table 3. Steps of Structure Determination as Non-framework Atomic Positions Were Found number of ions or atoms per unit cella step Na10 Na11 Na12 Na2 Na3 S1 S2 c,d 1 2 4.19(14) 3 3.76(13) 1.69(18) 4 4.38(19) 1.99(19) 3.1(3) 5e 1.8(5) 5.0(5) 1.3(6) 5.3(3) f 6 1.0(7) 4.1(6) 2.0(7) 3 7 1.0(7) 4.2(6) 2.0(6) 3 0.24(8) 8 1.5(5) 4.4(7) 2.7(7) 3 0.23(8) 9 0.4(9) 2.63(8) 5.6(6) 3 0.22(11) 0.20(8) 10 0.5(8) 2.3(8) 6.1(6) 3 0.22(11) 0.24(9) 0.72(24) 11g 1.03(15) 3.14(15) 3.84(15) 3 0.32(14) 0.23(9) 0.59(21) h 12 1.01(15) 3.75(15) 3.24(15) 3 0.36(14) 0.21(6) 0.63(18) i 13 1.08(15) 4.25(15) 2.67(15) 3 0.37(15) 0.21(6) 0.63(18) 14 0.84(15) 4.31(15) 2.85(15) 3 1.5(3) 0.73(8) 2.18(23) j 15 1 4.59(13) 2.41(13) 3 2.1(4) 1 3 k 16 1 4.39(13) 2.61(13) 3 1 1 3 17l 1 4.31(13) 2.70(13) 3 1 1 3 m 18 1 4 3 3 1 1 3 n 19 1 4 3 3 1 1 3 aThe

S3

0.14(5) 0.17(5) 0.16(5) 0.17(5) 0.17(5) 1

S4

2.3(3) 2.3(4) 3.5(6) 2.3(4) 2.5(4) 2.5(4) 1.9(3) 1.7(4) 2.4(4) 2 2 2

error indicesb R1 R2 0.21 0.55 0.14 0.43 0.118 0.355 0.109 0.336 0.0740 0.2441 0.0769 0.2510 0.0761 0.2474 0.0728 0.2328 0.0717 0.2300 0.0721 0.2295 0.0719 0.2312 0.0720 0.2313 0.0718 0.2312 0.0735 0.2335 0.0734 0.2358 0.0736 0.2356 0.0732 0.2358 0.0731 0.2355 0.0750 0.2388

numbers in parentheses are the estimated standard deviations (esds) in the units of the least significant figure given for the corresponding parameter. bDefined in footnotes to Table 1. cThe framework atoms were refined anisotropically. dAn extinction parameter (EXTI) was introduced and refined. eNa11 and Na12 were refined anisotropically. fThe occupancy at Na2 (an 8-ring position) was fixed at 3.00, its maximum value by symmetry. gThe sum of the occupancies at Na10, Na11, and Na12 (the 6-ring positions) were constrained to be 8. hS1/S2 was constrained to be 1/3. iNa3 and S1 were refined anisotropically. jThe occupancies at Na10 and S1 were fixed, at 1.0 and that at S2 was fixed at 3.0. kThe occupancy at Na3 was fixed at 1.00. lThe occupancy at S4 was fixed at 2.00. mThe occupancy at Na11 was fixed at 4.00 and that at Na12 was fixed at 3.0. nThe occupancy at S3 was fixed at 1.00.


The Journal of Physical Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

Table 4. Positional, Thermal, and Occupancy Parametersa occupancyc atomic Wyckoff x y z U11 or Uisob U22 U33 U23 U13 U12 position position varied constrained fixed 0d 0d T (Si,Al) 24(k) 0d 18316(5) 37003(5) 269(6) 234(6) 151(6) 31(2) 24 d d d d d 22037(43) 50000 0 0 O1 12(h) 0 906(33) 651(29) 189(14) 0 12 0d 0d O2 12(i) 0d 29641(31) 29641(31) 662(24) 438(14) 438(14) 314(16) 12 O3 24(m) 11234(20) 11234(20) 33661(29) 445(10) 445(10) 567(17) 54(9) 54(9) 139(11) 24 e,f Na10 8(g) 22618(111) 22618(111) 22618(111) 261(51) 0.9(4) 1.0 Na11 8(g) 21941(108) 21941(108) 21941(108) 814(73) 814(73) 814(73) 550(65) 550(65) 550(65) 4.7(8) 4.0f,g Na12 8(g) 17478(131) 17478(131) 17478(131) 961(84) 961(84) 961(84) 661(95) 661(95) 661(95) 2.8(8) 3.0f,g d Na2 24(k) 0 39510(357) 46241(309) 1513(170) 4.4(5) 3.0h d d d d d 0 0 Na3 6(e) 0 0 17138(430) 1151(253) 1151(253) 838(295) 0 0.9(4) 1.0i S1 8(g) 36034(242) 36034(242) 36034(242) 1270(137) 1270(137) 1270(137) -116(143) -116(143) -116(143) 0.60(15) 1.0e,j S2 48(n) 18882(411) 36691(553) 40391(564) 1902(244) 2.6(4) 3.0e,j d d d 0 0 S3 1(a) 0 5059(661) 0.17(6) 1.0k d S4 24(k) 0 7904(462) 15420(644) 1637(213) 2.7(7) 2.0k aPositional parameters x 105 and thermal parameters x 104 are given. Numbers in parentheses are the estimated standard deviations (esds) in the units of the least significant figure given for the corresponding parameter. bThe anisotropic temperature factor is exp[-2π2a-2(U11h2 + U22k2 + U33l2 + 2U23kl + 2U13hl + 2U12hk)]. cOccupancy factors are given as the number of atoms or ions per unit cell. dExactly, by symmetry. eThe occupancies at Na10 and S1 were fixed at 1.0 and that at S2 was fixed at 3.0. fThe sum occupancies at Na10, Na11, and Na12 at 6-ring positions were constrained to be 8. gThese occupancies were fixed as described in section 3. hThe occupancy at Na2 (an 8-ring position) was fixed at 3.00, its maximum value by symmetry. iThe occupancy at Na3 was fixed at 1.00. jS1/S2 was constrained to be 1/3. kS3/S4 was constrained to be 1/2.


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Table 5. Selected Interatomic Distances (Å) and Angles (deg)a distances angles T-O1 1.6483(17) O1-T-O2 107.1(3) T-O2 1.6469(12) O1-T-O3 112.15(14) T-O3 1.6696(12) O2-T-O3 107.49(15) weighted meanb 1.659 O3-T-O3 110.25(24) Na10-O3 Na11-O3 Na12-O3

2.380(9) 2.334(8) 2.248(4)

T-O1-T T-O2-T T-O3-T

148.0(4) 156.1(4) 142.08(23)

Na2-O1 Na2-O2

2.18(4) 2.35(4)

O3-Na10-O3 O3-Na11-O3 O3-Na12-O3

108.6(6) 111.8(5) 118.7(3)

Na3-O3

2.79(4) O1-Na2-O2

71.4(13)

Na10-S1 Na10-S2 Na2-S2 Na3-S3

2.83(6) 2.80(5) 2.43(5) 2.09(5)c

O3-Na3-O3

58.7(9)

Na10-S1-S2 66.7(19) S2-S1-S2 105.4(22) S1-S2 2.16(5) Na10-S2-S1 68.3(19) Na2-S2-S1 173(3) S4-O3 2.64(7) O3-S4-S3 145.0(13) S3-S4 2.11(8) S4-S3-S4 102.0(14) aThe numbers in parentheses are the estimated standard deviations (esds) in the units of the least significant digit given for the corresponding value. b(T-O1 + T-O2 + 2(T-O3))/4. cThis distance is too short to be correct. This is discussed in the penultimate paragraph of section 5.



Table 6. Unit Cell Charge Budget atom ionsa occupancyb position Na10 Na+ 1 + Na11 Na 4 Na12 Na+ 3 Na2 Na+ 3 + Na3 Na 1

M-O,c Å

r,d Å

2.380(9) 2.334(8) 2.248(4) 2.18(4) 2.79(4)

1.06 1.01 0.93 0.86 1.47

Page 24 of 33

CNe

charge x occ.

4 1+ 3 4+ 3 3+ 3 3+ 4 1+ Σ charges = 12+ 2S1,S2 S4 1 4 2S3,S4 S32+ 1 2.64(7)f 1.32g 4 2+ Σ charges = 0 aExtraframework ions. bIons per unit cell. cShortest Na+-O and S+-O bond lengths. dRadii of Na+ ions obtained by subtracting 1.32 Å (the conventional radius of the oxide ion22) from the shortest Na+-O bond lengths. eCoordination numbers. fShortest S 2+-O bond lengths; these are the S4-O3 3 g + distances. Radii of S ions obtained by subtracting 1.32 Å (the conventional radius of the oxide ion22) from the shortest S32+-O bond lengths.


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Table 7. Comparative Geometries substance species S-S (Å) a Na12-A + S S8 1.94(8) S(s)b Na12-A + Sc Cd46-X + Sd

S8 S32+ S42n-S42+ S44+

Na2SO3(s)e aRef. 4. bRef.

2.046(3) 2.11(8) 2.16(5) 2.47(15) 2.60(19) 2.38(17) 2.17(2)

SO3223 cThis report.

dRef.

S-S-S (deg) 128(9) 119(8) 108.2(6) 102.0(14) 105.4(22) 116(6) 102(6)

S-O (Å) 3.21(9)

S-S-O (deg) 113(4)

2.64(7)

145.0(13)

60.0(8)

3.380(9)

105.69(17)f 1. eRef. 24.

fO-S-O

2.58(8) 3.00(9) 116.6(4) 116.6(11) 175.89(14)

1.504(3) (deg).



Table 8. Na+ Positions in Three Na-A Structures position ring Na-Aa Na12-A + Sb d e occ. coord. occ.d coord.e 6ring

(x,x,x)

8

0.200(1)

8

0.209(2)

Na12-A + Sc occ.d coord.e 4 0.2194(11) 3 0.1748(13) 1 0.2262(11)

(0,y,y) 3 0.429(3) 3 0.440(12) (0,y,z) 3 0.395(4), 0.462(3) (x,x,0.5) 1 0.204(7) 4-ring (0,0,z) 1 0.171(4) aAnhydrous Na-A, ref. 27. bRef. 4. cThis report. dOccupancy, number of Na+ ions per unit cell. eValues of the coordinates x, y, or z. 8-ring


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(figure captions)

Figure 1.

Stereoview of a perthiosulfite ion, S42-, in its coordination environment.

S42-

bonds to three 8-ring Na+ ions at Na2 and to one 6-ring Na+ ion at Na10 in the large cavity.

The zeolite A framework is drawn with open bonds; solid bonds

are used to show the clusters. and Al.

Figure 2.

T represents the tetrahedral framework atoms Si

Ellipsoids of 20% probability are shown.

Stereoview of a representative large cavity.

See the caption to Figure 1 for

other details.

Figure 3.

Stereoview of a S32+ ion. sodalite cavity.

Figure 4.

S32+ bonds to four 6-ring oxygen atoms in each

See the caption to Figure 1 for other details.

Stereoview of a representative sodalite cavity.

Na3 and S3 appear to be too

close; this is discussed in the penultimate paragraph of section 5.

See the

caption to Figure 1 for other details.

Figure 5.

The perthiosulfite anion and the trisulfur cation. are shown.


Ellipsoids of 10% probability


Figure 1.

Lim et al.

Note to editor: This stereoview is the correct width, ca. 4 1/4 inches black to black, for clearest viewing by adult human eyes.

If it is enlarged it will not be viewable in stereo by the average reader.


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Figure 2.

Lim et al.

Note to editor: See the note to Figure 1 for its correct size.



Figure 3.

Lim et al.



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Figure 4.

Lim et al.




Figure 5.

Lim et al.


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TOC Graphic


Disproportionation of an Element in a Zeolite. III. Crystal Structure of a

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