1

Polyoxometalates Paneling through {Mo2O2S2} Coordination: Cation-Directed Conformations and Chemistry of a Supramolecular Hexameric Scaffold.

Jérôme Marrot,a Marie Anne Pilette,a Mohamed Haouas,a Sébastien Floquet,a

Francis Taulelle,a Xavier Lopez,b Josep M. pobletb and Emmanuel Cadota

Supporting Information

a Institut Lavoisier de Versailles. UMR 8180. Université de Versailles Saint

Quentin, 45 Avenue des Etats-Unis, 78035 Versailles (France)

b Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Marcel·lí

Domingo s/n, 43007, Tarragona, Spain

*Corresponding authors : E-mail: cadot@chimie.uvsq.fr

2

Organization of the supporting information section

SI, 1. Experimental section

SI, 1.1. Physical methods

SI, 1.2. NMR measurements

SI, 1.3. X-ray Crystallography

SI, 1.4. Computational details

SI, 1.5. Syntheses

SI, 2. Determination of initial condition from 39K NMR line

area.

SI, 3. Calculation of x(K+aq) versus time from 39K NMR

parameters

SI, 4. First-order Law for the process of aqueous potassium

formation.

SI, 5. UV-vis of KLi35-1a in aqueous solution.

SI, 6. Geometry evolution of 1a during DFT optimization

SI, 7. Additional references

3

SI, 1. Experimental section

SI, 1.1. Physical methods.

Water content was determined by thermal gravimetric

analysis (tga7, Perkin-Elmer). Infrared spectra were recorded

on a Magna 550 Nicolet spectrophotometer, using KBr pellet.

Spectrophotometric measurements were performed at room

temperature using a Perkin Elmer Lambda 19 UV-Vis-NIR

spectrophotometer. Elemental analyses were performed by the

Service Central d’Analyses Elémentaires du CNRS, 69390

Vernaison, France. EDX measurements were carried out on a JEOL

JSM 5800LV apparatus.

SI, 1.2. NMR measurements. 183W NMR spectra were performed from solutions in 10 mm

tubes on a Bruker Avance 300 operating at 12.5 MHz or on a

Bruker DRX500 operating at 20.8 MHz. Chemical shifts were

referenced to the external 2 M sodium tungstate in alkaline D2O

(δ = 0 ppm) and were measured by the substitution method, using

a saturated solution of dodecatungstosilicic acid (H4SiW12O40)

in D2O as a secondary external standard (δ = -103.8 ppm). 39K

NMR spectra were recorded on a Bruker DRX500 operating at 23.3

MHz in 10 mm tubes, and using spin-echo sequence with

repetition delay 0.9 s, 90° and 180° pulses 35 and 70 µs

respectively, and echo delay 80 µs. A 2 M potassium chloride in

water is used as external reference for the chemical shifts

measurements.

SI, 1.3. X-ray Crystallography.

Structures of complexes K3.5Na32.5-1a•120H2O, K1Li35-

1a•~200H2O, K34.5Na1.5-1b•90H2O, Rb14Li10-2•90H2O, Cs15Li9-2•52H2O

and Cs9Li3-3•37H2O were obtained from single crystals X-ray

4

analysis. All crystals were air sensitive and then mounted in

sealed Lindeman tubes to prevent any loss of crystallization

water. X-ray intensity data collections were carried at RT on

a Bruker-Nonius X8-APEX2 CCD area-detector diffractometer

using Mo-Kα radiation (λ = 0.71073 Å). Data reduction was

accomplished using SAINT V7.03 (APEX2 version 1.0-8; Bruker

AXS: Madison, WI, 2003). An empirical absorption correction

based on the method of Blessing1 was applied by using the

SADABS program.2 The structures were solved by direct methods

and refined by the full-matrix least squares method on all F2

data by using the SHELX-TL package.3 Relevant crystallographic

data for compounds are reported in Table 1. Heavier atoms

(mainly tungsten and molybdenum) were initially located by

direct methods. The remaining non-hydrogen atoms were located

from Fourier differences and were refined with anisotropic

thermal parameters. The disordered atoms, alkali cations and

oxygen atoms of crystallized water were isotropically refined.

As usually observed in polyoxometalate structures, the alkali

counter-cations and crystallization water molecules are not

entirely located, probably due to severe disorders within the

crystals. Cif files containing X-Ray crystallographic data of

K3.5Na32.5-1a•120H2O, K1Li35-1a•~200H2O, K34.5Na1.5-1b•90H2O, Rb14Li10-

2•90H2O, Cs15Li9-2•52H2O and Cs9Li3-3•37H2O are added in

supporting information and available free of charge via the

Internet at http://pubs.acs.org. Figures 1-6 were generated by

Diamond version 3.1 (copyright Crystal Impact GbR). Crystal

structures may be obtained from the Fachinformationszentrum

Karlsruhe, 76344 Eggenstein-Leopoldshafen, Germany (fax: (+49)

7247-808-666; e-mail: crysdata@fiz-karlsruhe. de), on quoting

the depository number CSD-423600, CSD-423601, CSD-423602, CSD-

423603, CSD-423604, CSD-423605 for K3.5Na32.5-1a•120H2O, K1Li35-

1a•~200H2O, K34.5Na1.5-1b•90H2O, Rb14Li10-2•90H2O, Cs15Li9-2•52H2O

and Cs9Li3-3•37H2O, respectively.

5

Table S1. Summary of Crystal Structure Data

K3.5Na32.5[1a] KLi35[1a] K34.5Na1.5[1b] Rb14Li10[2] Cs15Li9[2] Cs9Li3[3]

formula As6H240K3.5Mo18 Na32.5O336S18W54

As6H392Kli35Mo18 O412S18W54

As6H192K34.5Mo18Na1.5 O312S18W54

As4H2140246Li10Mo12O246Rb14S12W36

As4Cs15H128Li9Mo12O208S12W36

As2Cs9H74Li3Mo6 O109S6W18

FW, g.mol-1 19183.37 19950.56 19250.39 13871.87.1 13967.4 7272.15 T, K 293(2) 293(2) 296(2) 298(2) 298(2) 296(2)

crystal size (mm)

0.2x0.08x0.06 0.18x0.08x0.04 0.18x0.10x0.08 0.14x0.10x0.10 0.12x0.06x0.04 0.32x0.22x0.08

crystal system Triclinic Orthorhombic Monoclinic monoclinic Monoclinic hexagonal space group P1� Pnma P21/n C2/c C2/c P6�62m

a, Å 22.217(8) 39.7619(8) 21.1120(9) 47.437(1) 47.2304(5) 22.818(3) b, Å 25.490(9) 37.814(1) 44.991(2) 18.6347(3) 18.6529(3) 22.818(3) c, Å 37.77(2) 25.0128(5) 38.415(2) 36.2086(7) 36.3782(1) 21.265(4)

α, deg 75.41(2) 90 90 90 90 90

β, deg 85.28(2) 90 96.196(2) 127.567(1) 126.753(1) 90

γ, deg 83.71(2) 90 90 90 90 120 V, Å3 20542(2) 37608(2) 36276(2) 25370.9(8) 25678.0(5) 9588(3) Z 2 4 4 4 4 2

ρcalc , g.cm-3 3.101 3.524 3.525 3.631 3.613 2.516

µ(Mo Kα), cm-1 16.316 17.784 18.789 20.219 19.416 13.284

λ(Mo Kα), Å 0.71073 0.71073 0.71073 0.71073 0.71073 0.71073 θ range, deg 0.92 / 24.63 0.96 / 27 0.7 / 22.68 1.08 / 24.50 1.08 / 29.95 0.96 / 30.02

data collected 121443 364256 412250 281996 67225 169212 unique data 64874 41616 48232 21074 22575 9945 unique data

I>2σ(I) 32184 27789 34609 13445 11984 7896

no. parameters 3172 1933 4009 1316 1134 201 R(F)a 0.0731 0.0551 0.0445 0.0588 0.0590 0.0531 Rw(F2)b 0.1937 0.1506 0.1235 0.1731 0.1605 0.1399 GOF 0.987 1.188 1.100 1.062 0.939 1.270

∑

∑ −=

cFcFoF

Ra1 ∑

∑ −= 2)2(

2)22(

oFwcFoFw

wRb bPaPoFw

++= 2)(221σ

6

SI, 1.4. Computational details.

Density Functional Theory (DFT) calculations have been

carried out on the [(AsW9)2n(Mo2S2O2)3n]-like (n = 1-3) series of

compounds. We have used the ADF2008 program4,5,6 with the

generalized gradient approximation (GGA), applying the Xα

model with Becke’s corrections7 for describing exchange, and

the VWN parameterization8 with Perdew’s corrections for

correlation9 (BP86 functional). All valence electrons were

described by Slater-type functions with basis sets of double-ξ

for the hexamer structure or triple-ξ + polarization quality

for other compounds. Core electrons were kept frozen and

described by single Slater functions (core shells by atom: O:

1s; S: 1s-2p; As: 1s-3p; Mo: 1s-3d; W: 1s-4f). We applied

scalar relativistic corrections to core electrons by means of

the zeroth-order regular approximation (ZORA) with the core

potentials generated using the DIRAC program. In some

calculations, the conductor-like screening model (COSMO)10 has

been applied to account for solvent effects (water, ε = 78.4).

The solvent cavity surrounding the anions was created using

the solvent-excluding method with fine tesserae. The ionic

radii for the atoms that actually define the size of the

solvent cavity were chosen to be 1.26 Å for W, 1.20 Å for Mo,

0.80 Å for As, 1.52 Å for oxygen, 1.60 for Rb and 1.84 Å for

S. All the electronic configurations are closed shell.

SI, 1.5. Syntheses.

The precursors K2[I2Mo10O10S10(OH)10(H2O)5]•20H2O11 and Na9[α-

AsW9O33].13H2O12 were prepared as described in literature and

characterized by routine methods. All chemicals were purchased

from Aldrich Chemicals and used without further purification.

Synthesis of the crude precursors. K2[I2Mo10O10(OH)10(H2O)5]

(3.42 g, 1.49 mmol) was dissolved in 18.6 mL of molar

7

hydrochloric acid. The total volume was adjusted to 100 mL

with distilled water and the resulting mixture was heated at

ca 35°C. After removing of a slight amount of a yellow cloudy

precipitate, Na9[α-AsW9O33].13H2O (10 g, 3.7 mmol) was added to

the filtrate under vigorous stirring. The resulting dark red

solution was kept at 35°C for 30 minutes before cooling in an

ice bath. The crude precursors CxNa6-x[(AsW9O33)(Mo2O2S2)1.5]•nH2O

(noted CxNa6-xP•nH2O) with C = K, Rb or Cs are obtained by

precipitation using the corresponding precipitating agent i.e

KCl, RbCl or CsCl.

Na0.83K5.16P•16H2O was precipitated by addition of potassium

chloride (16 g; 0.21 mol) to the red solution. The orange

solid was isolated by filtration, washed and dried with

ethanol and ether. Yield: 80% (9.4 g). Anal. Calcd. for AsH32

K5.16Mo3Na0.83O52S3W9 (FW = 3198.75 g. mol-1): As, 2.34; K, 6.31;

Mo, 9.00; Na, 0.60; S, 3.00; W, 51.72. Found: As, 2.38; K,

6.42; Mo, 8.91; Na, 0.65; S, 3.14; W, 50.85.

Na1.33Rb4.66P•15H2O was precipitated by addition of rubidium

chloride (8.5 g; 70.8 mmol) to the red solution. The orange

solid was isolated by filtration, washed and dried with

ethanol and ether. Yield: 70% (8.7 g). Anal. Calcd. for

AsH30Mo3Na0.83O51Rb4.66S3W9 (FW = 3389.05 g. mol-1): As, 2.21; Mo,

8.49; Na, 0.90; Rb, 11.76; S, 2.83; W, 48.82. Found: As,

2.17; Mo, 8.29; Na, 0.93; Rb, 11.82; S, 2.92; W, 47.72.

Na1.08Cs4.91P•12H2O was precipitated by addition of cesium

chloride (3.75 g; 21.6 mmol) to the red solution. The orange

solid was isolated by filtration, washed and dried with

ethanol and ether. Yield: 85 % (11.3 g). Anal. Calcd. for

AsCs4.91H24Mo3Na1.08O48S3W9 (FW = 3583.91 g. mol-1): As, 2.09; Cs,

18.23; Mo, 8.03; Na, 0.69; S, 2.67; W, 46.16. Found: As, 2.16;

Cs, 18.46; Mo, 8.12; Na, 0.72; S, 2.81; W, 45.67.

K3.5Na32.5[(AsW9O33)6(Mo2O2S2)9]•120H2O, K3.5Na32.5-1a.

Na0.83K5.16P•16H2O (8.25 g; 2.58 mmol) was dissolved in 80 mL of

mol.L-1 NaCl aqueous solution and kept to slowly evaporate in

8

air. After few days, red cubic crystals suitable for X-Ray

diffraction studies were isolated (3.75 g, yield 31 %). Anal.

Calcd. (%)for As6H240K3.5Mo18Na32.5O336S18W54 (FW = 19181.7 g.mol-1):

As, 2.34; K, 0.71; Mo, 9.00; Na, 3.89; S, 3.01; W, 51.75.

Found: As, 2.22; K, 0.67; Mo, 8.48; Na, 3.94; S, 3.25; W,

50.40. FT-IR (cm-1): 950 (s); 881 (s); 796 (m); 695 (s); 469

(w).

KLi35[(AsW9O33)6(Mo2O2S2)9]•196H2O, KLi35[1a]. Na0.83K5.16P•16H2O

(6 g; 1.88 mmol) were dissolved in 80 mL of 10 mol.L-1 LiCl

aqueous solution and kept to slowly evaporate in air. After

two days, red parallelepipedic crystals suitable for X-Ray

diffraction studies are isolated (3.31 g, yield 53 %). Anal.

Calcd. (%) for As6H392Kli35Mo18O412S18W54 (FW = 19950.56 mol.L-1):

As, 2.24; K, 0.19; Li, 1.21; Mo, 8.63; S, 2.87; W,49.59.

Found: As, 2.24; K, 0.20; Li, 1.41; Mo, 8.75; S, 2.77; W,

49.07. FT-IR (cm-1): 950 (s); 881 (s); 796 (m); 695 (s); 469

(w). TGA: Loss of ca 196 water molecules between RT and 200°C.

(EDX): W/K = 52.97 (expected 54); Mo/K = 16.67 (expected

18.0); W/As = 9.81 (expected 9.0); W/Mo = 3.33 (expected 3.0),

Mo/S = 1.02 (expected 1.0).

K10.5Li25.5[(AsW9O33)6(Mo2O2S2)9]•200H2O, K10.5Li25.5-1.

Na0.83K5.16P•16H2O (5 g; 1.56 mmol) was dissolved in 80 mL of 3

mol.L-1 LiCl aqueous solution and kept to slowly evaporate in

air. After two days, red parallelepipedic crystals were

isolated (3.82 g, yield 72 %). Anal. Calcd. (%) for

As6H400K10.5li25.5Mo180416S18W54 (FW = 20324.96 mol.L-1): As, 2.21; K,

2.02; Li, 0.87; Mo, 8.50; S, 2.83; W,48.84. Found: As, 2.24;

K, 0.20; Li, 0.99; Mo, 8.95; S, 2.97; W, 50.28. FT-IR (cm-1):

950 (s); 881 (s); 796 (m); 695 (s); 469 (w).

K34.5Na1.5[(AsW9O33)6(Mo2O2S2)3(Mo2O2S2(H2O))6]•90H2O, K34.5Na1.5-

1b. Na0.83K5.16P•16H2O (9.4 g; 2.94 mmol) was dissolved in 50 mL

of water and kept to slowly evaporate in air. After two days,

red parallelepipedic crystals suitable for X-Ray diffraction

studies were isolated (4.1 g, yield 43 %). Anal. Calcd. (%)

9

for As6H192K34.5Mo18Na1.50312S18W54 (FW = 19248.87 g.mol-1): As, 2.33;

K, 7.00; Mo, 8.97; Na, 0.18; S, 2.99; W, 51.57. Found: As,

2.35; K, 6.92; Mo, 9.19; Na, 0.16; S, 3.27; W, 51.09. FT-IR

(cm-1): 948 (s); 967 (w); 868 (s); 792 (s); 691 (s); 515 (w);

484 (w); 450 (w).

Rb14Li10[(AsW9O33)4(Mo2O2S2(H2O)2)6]•90H2O, Rb14Li10[2].

Na1.33Rb4.66P•15H2O (1 g; 0.295 mmol) was dissolved in 15 mL of

1mol.L-1 LiCl aqueous solution and kept to evaporate slowly in

air. After one week, red cuboidal crystals suitable for X-Ray

diffraction studies were isolated (0.58 g, yield 58 %). Anal.

Calcd. (%) for As4H204Li10Mo120246Rb14S12W36 (FW = 13546.15 g.mol-1):

As, 2.15; Li, 0.50; Mo, 8.31; Rb, 8.63; S, 2.77; W, 47.45.

Found: As, 2.23; Li, 0.40; Mo, 8.96; Rb, 8.72; S, 3.02; W,

48.38. FT-IR (cm-1): 951 (s); 878 (s); 800 (s); 709 (s); 504

(w); 463 (w).

Cs15Li9[(AsW9O33)4(Mo2O2S2(H2O)2)6]•52H2O, Cs15Li9[2]•52H2O.

Na1.08Cs4.91P•12H2O (1 g; 0.279 mmol) was dissolved in 20 mL of 1

mol.L-1 LiCl aqueous solution and kept to evaporate slowly in

air. After two weeks, red parallelepipedic crystals suitable

for X-Ray diffraction studies were isolated (0.47 g, yield 51

%). Anal. calcd (%) for As4Cs15H128Li9Mo12O208S12W36 (FW = 13966.4

g.mol-1): As, 2.14; Cs,14.27; Li, 0.44; Mo, 8.24; S, 2.75; W,

47.38. Found: As, 2.07; Cs, 15.29; Li, 0.44; Mo, 8.10; S,

2.52; W, 47.90. FT-IR (cm-1): 951 (s); 878 (s); 800 (s); 709

(s); 504 (w); 463 (w).

Cs9Li3[(AsW9O33)2(Mo2O2S2(H2O)2)3]•37H2O, Cs9Li3[3].

Na1.08Cs4.91P•12H2O (6 g; 1.67 mmol) was dissolved in 120 mL of 1

mol.L-1 LiCl aqueous solution. The solution was heated at 75°C

for 60 minutes and then kept to slowly evaporate at room

temperature in air. After two days, red hexagonal crystals

suitable for X-Ray diffraction studies were isolated (2.01 g,

yield 33 %). Anal. Calcd. (%)for As2Cs9H74Li3Mo6O109S6W18 (FW =

7262.15 g.mol-1): As, 2.06; Cs,16.47; Li, 0.28; Mo, 7.93; S,

2.64; W, 45.56. Found: As, 2.43; Cs, 16.54; Li, 0.33; Mo,

10

7.81; S, 2.61; W, 45.27. FT-IR (cm-1): 951 (s); 878 (s); 800

(s); 709 (s); 504 (w); 463 (w).

SI, 2. Determination of initial conditions from combined 39K

and 183W NMR kinetic.

During the Kinetic, two processes expressed by equations 1 and

2, were involved:

HK ⇆ H + K (1)

HKx → 3D + xK (2)

The following conservative equations can be written:

xHK + xK = 1 (3) conservation of potassium

xHK + xH + 3xD = 1 (4) conservation of POM with POM = HK, H

and D species)

The experimental observations needed are :

i) The variation of the line area of the 39K :

Aobs = α AHK + β AK (5)

where α and β correspond to the observability factor for the

crypted potassium (HK species) and aqueous potassium (K

species), respectively.

Equation (5) can be derived to give the normalized line area

AN: AN = α/β xHK + xK

with 0<AN<1, 𝐴𝑁 = 𝐴𝑜𝑏𝑠𝛽𝐴𝐾

∞ and 𝛽𝐴𝐾∞ = 𝐴𝑜𝑏𝑠∞ = 33000 𝑎.𝑢.

and thereby gives equation (6) from equation (3):

AN = α/β + (1-α/β).xK (6)

The equilibrium constant is expressed from equation (1):

𝐾𝑒𝑞 =𝑥𝐻𝑥𝐾𝑥𝐻𝐾

= [𝑥𝐾 − 3𝑥𝐷]. 𝑥𝐾

1 − 𝑥𝐾

and leads to the second-order equation (7):

11

𝑥𝑘2 + �𝐾𝑒𝑞 − 3𝑥𝐷�.𝑥𝑘 − 𝐾𝑒𝑞 = 0 (7)

equation (7) produces a single physically suitable root,

expressed by equation (8)

𝑥𝑘 = 12

��−�𝐾𝑒𝑞 − 3𝑥𝐷�� + ��𝐾𝑒𝑞 − 3𝑥𝐷�2

+ 4𝐾𝑒𝑞� (8)

Equation (8) can be combined with equation (6) to lead to

equation (9):

𝐴𝑁(𝑡) = 𝛼𝛽

+ (1−𝛼/𝛽)2

. ��−�𝐾𝑒𝑞 − 3𝑥𝐷(𝑡)�� + ��𝐾𝑒𝑞 − 3𝑥𝐷(𝑡)�2

+ 4𝐾𝑒𝑞� (9)

The 𝑥𝐷(𝑡) function can be extracted from the 183W NMR kinetic

through simulation. The best fit (see Figure SIXXX) was

obtained with equation 10:

3𝑥𝐷(𝑡) = 1 − (0.03. 𝑡 + 1)−2,71 (10)

Then, the 3xD(t) function can be introduced within equation 9

such as : 𝐷(𝑡) = −�𝐾𝑒𝑞 − 3𝑥𝐷(𝑡)�, to give equation 11 :

𝐴𝑁(𝑡) = 𝛼𝛽

+ (1−𝛼/𝛽)2

. �[𝐷(𝑡)] + �𝐷(𝑡)2 + 4𝐾𝑒𝑞� (11)

Equation (11) contains two parameters α/β and Keq. The α and β

parameters corresponds to the fraction of magnetization

recovered after the spin-echo sequence and can be expressed

by:

𝛼 = 𝑒𝑥𝑝 �− 2𝜏𝑇2� = 𝑒𝑥𝑝[2𝜋𝜏∆ν𝐻𝐾] (12)

and

𝛽 = 𝑒𝑥𝑝[2𝜋𝜏∆ν𝐾]

where ∆νK and ∆νHK correspond to the intrinsic 39K NMR line width

of aqueous and crypted potassium species. Furthermore, ∆νHK can

be expressed as function of ∆ν(0), 𝑥𝑘(0) and ∆νK:

12

∆ν(0) = 𝑥𝑘(0)∆ν𝐾 + [1 − 𝑥𝐾(0)]∆ν𝐻𝐾

With ∆ν(0) = 3200Hz

And then introduced in equation 12 to produce equation 13

𝛼 = 𝑒𝑥𝑝 �2𝜋𝜏 �∆ν(0)−𝑥𝑘(0)∆ν𝐾 [1−𝑥𝐾(0)] �� (13)

The β factor can be directly estimated from the echo-delay

τ = 80 µs and ∆ν∞ = ∆νK = 200Hz. β = 0.99 ~ 1 was found.

Then, 𝑥𝑘(0) can be derived from equation 8 at t = 0 (xD(0) = 0)

to give equation 14 :

𝑥𝑘(0) = 12

�−𝐾𝑒𝑞 + �𝐾𝑒𝑞2 + 4𝐾𝑒𝑞� (14)

In definitive, the equation AN(t) depends on only a unique

parameter Keq and can be properly fitted with the experimental

values. The best fit (see Figure SIXX) was obtained for Keq =

0.1, giving with equation 13 and 14, α = 0.11 and xk(0) = 0.27

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 10 20 30 40 50 60 70

experimentalKeq = 0Keq = 0.1Keq = 0.3Keq = 0.6

Figure S1 : Normalized Signal Area AN(t); experimental (0) and calculated with Keq = 0 (red), Keq = 0.1 (green), Keq = 0.3 (blue)and Keq = 0.6 (violet)

13

SI,3. Calculation of xk(t) versus time from the 39K NMR

parameters

The fast exchange of the potassium ion between crypted and

aqueous environments leads to averaged 39K NMR parameters 𝑌�

with Y = linewidth (∆ν1/2), signal area (A) or chemical shift

(δ) expressed as :

𝑌� = (1-xK)YHK + xKYK with YHK and YK corresponding to the NMR parameters for crypted

or aqueous 39K nucleus, respectively. YK and YHK can be

calculated from the initial and limit conditions (t→∞) and

are given in the Table S3.

Table S3: 39K NMR parameters for crypted and aqueous potassium

ion 39K NMR parameter Crypted(HK) Aqueous(K)

∆ν1/2(Hz) 4310 200

δ(ppm) -24 -13 A (ua) 3630 33000

From initial conditions and 39K NMR parameters listed in Table

S3, the fraction of aqueous potassium xKaq can be calculated and

graphically shown in Figure S3.

Figure S2 : Graphical representation of the fraction of aqueous potassium

as function of time, calculated from 39K NMR signal area (O), chemical

shift()and line width (∆).

0

0.2

0.4

0.6

0.8

1

1.2

0 10 20 30 40 50 60 70

Signal AreaChemical shiftLinewidthMean ValuePolynomial (Mean Value)

t(hour)

xk(t)

14

SI, 4. First-order Law for the process of aqueous potassium

formation Kcryp → Kaq

Figure S3 : first-order linear plot Ln(1-xK) = f(t) consistent with

integrated law : xK = 1-exp(-kKt), calculated from 39K NMR parameters,

signal area (O), chemical shift () and linewidth (∆).

SI, 5. UV-vis spectrum of KLi35[1a](10-4 mol/L in aqueous

solution) reveals (see Figure S4) i) the two distinct

shoulders characteristic of the hexameric {POM6L9} anion at 410

nm (ε = ~ 38000 mol-1L.cm-1) and 350 nm (ε = ~ 87500 mol-1L.cm-

1); ii) the decreasing of the absorptions as function of time,

consistent with the dissociation of the complex.

y = -0.0517x - 0.3154R2 = 0.9989

-3

-2.5

-2

-1.5

-1

-0.5

00 10 20 30 40 50

Abso

rptio

n

Time increasing

λ / nm

t(hour)

Ln(1-xk(t)

Figure S4 : UV-vis spectra of KLi35[1a]

15

SI, 6. Geometry evolution of 1a during DFT optimization.

View of the initial (dashed lines) and final (solid lines)

relevant interatomic distances (blue: (As-As)h, red: (As-As)v,

orange: (Mo-Mo)pillars). In parentheses, the final distances.

10.72 Å

(12.46 Å)

11.35 Å

(13.46 Å)

9.17 Å

(13.27 Å)

As

Mo

16

SI, 7 Additional References

(1) Blessing, R. Acta Crystallogr., Sect. A., 1995, 51, 33.

(2) Sheldrick, G. M. SADABS; program for scaling and correction of

area detector data, University of Göttingen, Germany, 1997.

(3) Sheldrick, G. M. Acta Crystallogr., Sect. A., 1990, 46, 467;

SHELX-TL, version 5.03, Software Package for Crystal Structure

Determination, Sheldrick, G. M. Siemens Analytical X-ray

Instrument Division, Madison, WI, 1994.

(4) ADF2008.01, SCM, Theoretical Chemistry, Vrije Universiteit,

Amsterdam, The Netherlands, http://www.scm.com.

(5) Fonseca Guerra, C.; Snijders, J. G.; Te Velde, G.; Baerends, E.

J. Theor. Chem. Acc. 1998, 99, 391.

(6) Te Velde, G.; Bickelhaupt, F. M.; van Gisbergen, S. J. A.;

Fonseca Guerra, C.; Baerends, E. J.; Snijders, J. G.; Ziegler,

T. J. Comput. Chem. 2001, 22, 931.

(7) (a) Becke, A. D. J. Chem. Phys. 1986, 84, 4524. (b) Becke, A. D.

Phys. Rev. 1988, A38, 3098.

(8) Vosko, S. H.; Wilk, L.; Nusair, M. Can. J. Phys. 1980, 58, 1200.

(9)(a) Perdew, J. P. Phys. Rev. 1986, B33, 8822. (b) Perdew, J. P.

Phys. Rev. 1986, B34, 7406.

(10) (a) Klamt, A.; Schüürmann, G. J. Chem. Soc, Perkin Trans. 1993,

2, 799; (b) Andzelm, J.; Kölmel, C.; Klamt, A. J. Chem. Phys.

1995, 103, 9312; (c) Klamt, A. J. Chem. Phys. 1995, 99, 2224;

(d) Model implemented in the ADF package by Pye, C. C.; Ziegler,

T. Theor. Chem. Acc. 1999, 101, 396.

(11) Cadot, E. ; Salignac, B. ; Halut, S. ; Sécheresse, F. Angew.

Chem. Int. Ed. 1998, 37, 611.

(12) Tourne, C. ; Tourne G. C. R. Acad. Sci. Paris, 281 C 1975, 933.