Pradyutt Ghoshra yutt GhoshGDepartment of Inorganic ChemistryDepartment of Inorganic ChemistryIndian Association for the Cultivation of ScienceIndian Association fo2A & 2B Raja S. C.

or the Cn foC.C Mullick

Cultivation of Sciencee Ckk Road, Kolkata 700032

E2A EE-

& 2B Raja S. CC. MullicM&2A EE-mail: icpg@iacs.res.in

Indian Academy of Sciences, 82nd Annual Meeting, 5th Nov 2016, IISER Bhopal

Recognition, Sensing and Separation of Anions

Self-Assembly

Inorg. Chem. 2011, 50, 4772Inorg. Chem. 2013, 52, 4269

J. Am. Chem. Soc. 2006, 128, 9600

Inorg. Chem. 2015, 54, 4231

f AssemblyResearch in my Group

Anion Recognition

Basic Science: Coordination chemistry of anions

Potential Applications: Development of Selective Anion Receptor towards

Chemical SeparationClean EnvironmentSafe WaterChemical Sensing

Inorg. Chem. 2011, 50, 4229

Ion Sensing

Inorg. Chem. 2010, 49, 4447Chem. Commun. 2010, 46, 2962Dalton Trans. 2011, 40, 12540Org. & Biomol. Chem. 2011, 1972 Dalton Trans. 2011, 40, 6411

Inorg. Chem. 2014, 53, 8061Inorg. Chem. 2016, 55, 259Inorg. Chem. 2016, 55, 9212Chem. Eur. J. 2016, 23, 0000

Interlocked Molecules Chem. Commun. 2011,47, 6272Chem. Eur. J. 2011, 17, 13722

J. Org. Chem. 2014, 79, 11170Eur. J. Inorg. Chem. 2014, 2029

Org. Lett. 2015, 17, 1854Dalton Trans. 2015, 44, 15198

Lewis acid

hydrogen bonds

N An-

Anions

Hydrogen Bond

The Nobel Prize in Chemistry 1987

UCLA, USA

U. Louis Pasteur, France

Du Pont, USA

Factors that Regulate and Complicate Recognition

Solvation of anions plays a very important role. Anions generally have very high solvation energies that must be compensated by the host.

Thus when possible, anion binding should be carried out in apolar solvents or create a microenvironments.

• Size (larger than cations) and shape (more diverse)

• pH

SYNTHESIS

++ +

CAPSULE Enclose SpaceSizeFunction

Our Approaches

Building Blocks for Our Receptors Designing

NHNH

N

N

N

NN

N

O

NH

NH

O

NH

NH

S

NH

S

NHN

H H

Weak Interactions

N-H···Anion C-H···AnionAnion···

O OS

Recognition Elementsgggggggggggg

Platforms

Attached Units

Covalent Capsules towards Anion Recognition

NH

NH

N

N

NH

NH

NH

NH

Martell et al. 1991Lehn et al. 1989 Nelson et al. 1992

N

NH

NH

N

NH

NH

NH

NH

6.37 Å

10.95 Å 11.10Å

Ghosh et al. 2008

7.58Å

JJ.J. AmAm.m. Chemem.m. Sococ.c. 200505,, 12727,7, 131322 ;; Inorgrg.g. Chemem. 200505,, 4444,4, 75400;0;Angewew.w. Chemem.m. Intnt.t. EdEd.200606, 11818, 389191; Inorgrg.. Chemem.. 200606, 4545, 100466; Crystst.. Growthh Deses.. 200606, 666,, 26300;

Tetrahedronn 200707,, 6363,3, 1137171;; Inorgrg.g. Chemem.m. 200808,, 4747,7, 7992 ;; JJ.J. Orgrg.g. Chemm.m. 200808,, 7373,

91444;; Crystst.t. Growthh Deses.s. 200808,, 8888,8, 28422;; Crystst.t. Growthh Deses.s. 20133,, 1313,3, 32088JJ.JJ.. Orgrg.g. Chemm.20133,, 7878, 87599 .

12.19Å

Ghosh et al. 2013

Bowmanan-n-James et al.al ; BowmaInorg

nn amesJaJmaanrgrg. Chem.

s et amesm. m 2004,

aal.; , 434343434343, 3751

F

F

FF

FF

FF

F F

F

F

FFF

Br-

H2CH3DH4C

N4 N3 N2

C2gC1g

3.85

Inorgrg. Chemem. m. 200606, 437272;; Inorgrg. Chem. m. 2007, , 47699; ; Inorgrg. Chem. m. 2011,1,10693; ; Eur. J. J. Inorgrg. Chem. 2012, , 35466; ; Inorgrg. g. Chimim. m. Actaa 20100, 2886; ; CrystEng.Comm. 2014, 4796.

Moving towards half-capsule

Anion Log K

Cl- 1.80 2.56

Br- 1.70 2.04

NHHNHN

HN

O OO

NHHN

RRR

NHHNHN

R

O OO

RR

NHHNHN

RRR

Recognition Element: Dimensionality

Bicyclic amine cage

Chem. m. Communun. n. 200707, 5214; ; Dalton Transns.s. 200909, 41600; ; Chem. m. Commununn. 20111, , 474747, 8477

((Feature Articlele); ; Chem. m. Commununn. 20144, 4, 5050500, 10538 8 ((Feature Articlele).

Anion Assisted Capsular Assemblies

Guest n T Skcal/mol

Hkcal/mol

Gkcal/mol

log K(ITC)

log K(NMR)

SO42- 2.06 1.42 -4.96 -6.38 4.67 4.73

H2PO4- 1.01 -1.46 -8.37 -6.91 5.06 5.52

CO32- 1.86 3.90 -1.67 -5.57 4.07 4.04

CH3CO2- 1.03 -0.20 -6.22 -6.01 4.41 4.45

F- 1.01 5.36 -0.98 -6.34 4.65 4.06Cl- 0.96 4.53 -1.05 -5.58 4.08 3.42Br- 1.04 4.77 -0.57 -5.35 3.92 1.27

5.06 5.52

Solution State Anion Binding Study by ITC

F-

CO32-H2PO4

-AcO-

Arsenate Recognition in Aqueous Medium

Anion log K log Ka log Kb

HAsO42- 4.42 4.35 -

H2PO4- 3.62 3.62 5.52

SO42- 3.48 3.36 4.73

CO32- 2.68 - 4.04

Table 1. Association constant value of L in DMSO-d6/D2O (9:1, v/v) with different anion in DMSO-d6/D2O (1.1:1, v/v) at 298 K

a: log K value calculated in buffered condition, b: log K value calculated in DMSO-d6 solvent

4.42

Dalton Trans. s. 20133, , 424242,11371

Benzene platform based tripodal amides

Chem. m. Communun., , 200909, 5389 ((Hot articlele)e);; Inorgrg. Chem. m. 20100, 0, 49, 9, 943; Dalton Transns. s. 20144,

43, 206161; Chem. Commun. 2015, 51, 9070 ((FFeature article)).

Org. g. Letttt. 20100, 0, 122122, 328; Chem. m. Communun. n. 20111, , 474747,7, 6269; RSC Adv. v. 20144, 4, 626899 ;; RSC

Adv., , 20155, 5, 480600.

Hexaamide for Compartmental Recognition

[L][

-CH

]

[L]/[L]+[F-]

[][

-CH

C]

[L]/[L]+[F-]

[L][

-CH

]

[L]/[L]+[F-]

Synthetic Scheme

Ligand Anions Association constants (log K)

(kJ/mol)

1b

Cl¯ 4.68 -26.7Br¯ 3.87 -22.1I¯ 2.90 -16.5

NO3¯ 2.87 -16.4AcO¯ 3.43 -19.6

Halogen Bonding Assisted Anion Recognition

Host Guest Stoichiometry

Associationconstants (K, M-1) (kJ/mol) (kJ/mol) (kJ/mol)

1a Cl¯ 1:3K1= 6.00*104

K2= 9.43*103

K3= 9.55*102

(5.40 ± 0.4)*1011

1 = -6.92 = -14.63 = -6.0

1 = 20.42 = 8.13 = 11.0

1 = -27.32 = -22.73 = -17.0

1a Br¯ 1:3K1= 5.93*105

K2= 1.61*104

K3= 1.16*103

(1.11 ± 0.08)*1013

1 = -6.52 = -8.03 = -12.8

1 = 26.42 = 15.93 = 4.6

1 = -32.92 = -23.93 = -17.5

1a I¯ 1:3K1= 5.41*104

K2= 2.62*103

K3= 7.51*101

(1.06 0.04)*1010

1 = -6.22 = -10.03 = -15.3

1 =20.8

2 = 9.53 = -4.6

1 = -27.02 = -19.53 = -10.7

1b Cl¯ 1:1 1.37*105 -4.8 24.6 -29.31b Br¯ 1:1 3.35*104 -2.5 23.3 -25.8MP Cl¯ 1:1 K = 2.12*103 -13.2 5.8 -19MP Br¯ 1:1 K = 2.66*103 -14.8 4.7 -19.5MP I¯ 1:1 K = 1.49*103 -13.4 4.6 -18

Tuning the selectivity from Cl¯ to Br¯ via halogen bonding with association constant (logK1) 5.77 with Br¯.

hi Association

HB Versus XB: ITC studies

Bromide Complex

Chloride Complex

Chem.Commun. , 2015, 51, 14793-14796

Single crystal X-ray structural proof

1a + {(TBABr + TBACl); (w/w = 1:1)} Bromide Complex1a + {(TBABr + TBACl); (w/w = 1:4)} Bromide Complex1a + {(TBABr + TBACl); (w/w = 1:9)} Bromide Complex

1a + TBA salts of Br¯, Cl¯, I¯, ReO4¯, AcO¯, HSO4¯ , NO3¯ BBromide Complex

1a + TBA salts of Cl¯, I¯, ReO4¯, AcO¯, HSO4¯ , NO3¯

Chloride e Complexdee C

Bromide removal in presence of interfering anions

Chloride removal in presence of interfering anions

Potential Applications

Capturing aerial CO2 as CO32- in a dimeric capsule

Liquid-Liquid extraction of SO42- / CrO4

2- / F-

Liquid-Liquid extraction of KF / KCl

Solid-Liquid extraction of KBr

Aerial CO2

CO32-

Base

DMSO

H2O

: M

eOH

Capturing aerial CO222 as CO333222-2222-- in a capsule

(%)

LL RecycledL + CO3

2-

400038403680352033603200304028802720256030

40

50

60

70

80

90

LLL

Amide stretching frequencies of L: 1664 cm-1 (amide I) and 1649 cm-1(amide II);

CO32-Stretching

Frequencies of complex: 1377 cm-1

(asymmetric) & 1688 cm-1 (symmetric)

CO22013 and rising by about 2.0 ppm/yr.

Chemem.m. Communun.. 20100,0, 4646,6, 1082

Highly Efficient & Clean Extraction of SulfateCarbonate capsules of L as an pppppppp n n extractant

L2(CO32-) can be easily synthesized in very high yields.

L2(CO32-) is good soluble in non-polar organic solvents.

L2(CO32-) has relatively low association constant than L2(SO4

2-)

Sulfate Extraction Visual Detection

K2SO4K2SO4

ExtractionOrg. LayerOrg. Layer

CHCl3 / H2O1 eqv.1 eqv.

Complex +

CO32-Capsule

16 hydrogen bonds

+ K2SO4 K2SO4

ExtractionOrg. LayerOrg. Layer

CHCl3 / H2O1 eqv.1 eqv.

CO32- Capsule

BaCl2/H2O

ShakingBaSO4BaSO4

Quantitative Analysis of Extracted Mass

No of expt.

Wt. of carbonate

capsule (mg)

Wt. of K2SO4(mg)

Wt . of extracted mass (mg)

% of extraction

Wt. of BaSO4(mg)

% of extraction

1 21.84 1.95 22.04 99.2 2.32 95.0

2 22.04 1.87 21.95 97.9 2.39 96.9

3 22.38 1.98 22.64 99.4 2.46 98.3

99.2

97.9

99.4

95.0

96.9

98.3

Chem. Sci. i. 2012,, 3, 1522; ; Chem. Soc. Rev.v. 20122, 41, 3077

CO2 Sequestration as Carbonate

SO42- Extraction

CO Sequestration as Carbonnate

Capsular Assembly/Disassembly/Reassembly

7

8

9

1 0

1 1

1 2

1 3

Neutral pH

Basic pH

Extraction Carbonate capsule of Pentafluorophenylattached tris-urea

Carbonate capsule of 3-cyanophenyl

attached tris-urea

Sulfate YES YES

Thiosulfate NO YES

Phosphates NO NO

Chromate NO YES

Arsenate NO NO

Fluoride NO NO

Eur. J. J. Inorgrg. Chem. . 20144, 41344.

KF/KClNo Extraction

KF/KClControl Experiments

Dual-Control Experiments

host Strategy for Salts Extraction

Receptor % of KF extracted % of KCl extracted

L1 NIL NIL

L2 NIL NIL

L1 + L2 48 44

Salts % extracted at pH 4.5

% extracted at pH 6.3

% extracted at pH 9.3

KF 45 48 NIL

KCl 43 44 NIL

Chemem.m. Communun.. 20111 4747,7, 4721

Cl1

O10

N3N2 N4O2

K1

F16

O4

N2N3

N4 K1

O1

(a) (b)

(a) & (b) Monomeric structure of complexes 3 and 4 with partial atom-labeling and (c) 1-D polymer of complex 3. Non acidic hydrogen atoms are omitted for clarity.

(c)

Crystal Structures of Extracted Complexes

Dual Host Receptor for Ion-pair

Ligands should be composed of metal ions as well as anion binding sites either separated by a spacer or integrated into a unit

The design principle of L1 is as follows:

(i) 18-crown-6 is known for its use as a K+ selective receptor via coordination of suitable numbers of ethereal oxygen atoms with K+ ions;

(ii) Pentafluorophenyl substituted urea is popular for its use as a strongH-bond donor unit to anions

(iii) the lipophilic character of the pentafluorophenyl moiety also enhances the probability of salt extraction through the bilayer membrane.

NO3 HSO4KKa (M ) 741 851 87 501

Solvent: CD3CN, temperature 298 K, [L1] = ~2. 0 mM, anionsadded as TBA salts [TBAX] 1 0- 20 mM, errors < 1 0%.

4 3

Anion Binding Studies of L1

Anions Binding constant in presence of TBA+

(KTBA+; M-1)

Binding constant in presence of K+

(KK+; M-1)

KK+ / KTBA+

741 1288 1.74851 2455 2.88

NO3 87 324 3.72HSO4 501 575 1.15

4 3+

Highest cooperative effective observed for NO3

Cooperative Effect towards Anion Binding

Chem. m. Commun.n. , , 20155, 5, 5151511, 165144-4-16517

Binding of Cl- in absence of K+ Binding of Cl- in Presence of K+

TBACl n T S[cal mol-1]

H[cal mol-1]

G[cal mol-1]

Ka[ITC]

Absence of K+

1.21 0.05

783.74 -3490 69.90 -4273.74 1290

Presence of K+

1.01 0.01

1686.68 -3344 39.88 -5030.68 4898

Cooperativity study by ITC

Dynamic Properties of Capsular Assemblies

Acid/base Controlled Modulation of Capsular Size

Temperature Dependent Opening and Closing of Capsule stopper

Anion Assisted Assembly and Disassembly Processes

OH-

H+

Dihydrogen Phosphate Pseudo-capsule Hydrogen Phosphate Capsule

13.793 Å9.916 Å

Capsular Size Modulation

Chem. m. Communun. n. 20100, 0, 4646466, 674141; ; Eur. J. J. Inorgrg. Chem. m. 20133, 2673.

Tripodal Urea Receptors on Cyanuric Acid

SO444422222--- Capsule Assisted by TBA-cations

Eleven Hydrogen bonds: Six N-H···O and Five C-H···O H-bonds

~14 Å

~17 Å

L

LL

L

LL

LL

L

L

L

L

L

L

L

L

L

L

L

L

L

L

LLLL

LLLL

LLLL

LL

LL

LL

L

L

L

L

L

L

Anion log K

SO42- 5.74

H2PO4- 4.39

CH3COO- 3.41

Cl- 3.38

5.74

system T (K) D (10-10 m2 s-1) R (Å)

(n-Bu4N+)2SO42- 298 10.72 0.02 10.22 0.02

L 298 8.805 0.01 12.45 0.01Complex 1 298 7.127 0.01 15.39 0.01

313 7.752 0.01 14.14 0.01333 7.858 0.02 13.95 0.02

L + n-Bu4N+H2PO4- 298 8.112 0.01 13.52 0.01

L + n-Bu4N+CH3COO- 298 8.258 0.01 13.28 0.01L + n-Bu4N+NO3

- 298 8.521 0.01 12.87 0.01L + n-Bu4N+Cl- 298 8.289 0.01 13.23 0.01

2D-Å

DOSY NMR of CapsulesStokes-Einstein Equation

D = Diffusion Co-efficient, k = Boltzmann Constant, T = Temperature

= Viscosity Co-efficient, R = Hydrodynamic radii

2-

++heat

2-

++

Cool

(HCHO)n

HBr in HOAcBr

Br

Br

N

NH

NaOH/DMF-H2O

N

N

N

N

N

N

L

Chem. m. Communun., , 200909, 31844;4; Crystt Growth & Des s 20122, , 12212, 2097.

Encapsulated Water in Nitrate Zipped Staggered Dimer

HNO3

L

N

Anion Assisted Assembly and Disassembly

hem. (H(((((((((((((((((((((((((((((

HBr

m. Commun

(a) Coke Plant

(b) Blast furnace Water

Industrial Application

Cyanide is present in low concentration (~ 4 ppm) along with high content of chloride, sulfate, nitrate etc.

Interference of huge amount of ammonia and chloride

Toxicity limit of cyanide for human is 0.4 ppm and the Blast Furnace water can be recycled if the concentration falls down to 1.5 ppm

Currently 12 millions of gallons/ day is wasted every day which costs around 16 crore rupees/ year

Sample Conc. (onc. Co

((molnc. olol/ (momol /

1000 lt.)

Feed Feed Sample

After 30 Aftemin

% removal

BF-water 2 4.8 1.5 70

standard2 10 0.49 95

standard2 100 2.23 97.8

Sample Conc.mmol/Lt

FeedSample(ppm)

After 0.5 hour

After 1 hour

After 2 hours

After 3 hours

After 4 hours

After 24 hours

% removal

BF-Water

1 5.65 2.22 2.21 2.19 2.20 2.21 2.18 60

BF-Water

2 5.44 1.61 1.64 1.61 1.58 1.60 1.59 70

Monopodal C-H analogue, a weak non-covalent interaction

Development of Monopodal and Tripodal Ru(II) Complexes for sensing of phosphates

l

Anion recognition

unit

SignallingUnit

Phosphates Sensing through C-H Anion and Halogen Bonding Interaction

Phenanthroline and Triazole C-H based Integrated Ru(II) Complex exploiting C-H…anion Interaction for Sensing of Phosphate.

Tripodal C-H analogue to get better sensitivity

Monopodal C-I halogen bonding Analogue to compare between XB and HB interaction

Inorg. Chem. 2014, 53, 8061; Inorg. Chem. 2016, 55, 259; Chem. Eur. J. 2016, 23, 0000.

Highlights

Carb

onat

e Cy

cle

Extr

action

Cyc

le

Aerial CO2 sequestration as CO32- capsules

Liquid-Liquid extraction of SO42-/CrO4

2/F-

Liquid-Liquid extraction of KF/KCl

OH-

13.793 Å 9.916 Å

H+

Acid/base Controlled Modulation ofCapsular Size

Anion Assisted Assembly and Disassembly Processes

Temperature Dependent Opening and Closing of Capsule stopper

Developed anion coordination chemistry

Selective anion receptors

Arsenate encapsulation

Hydrated fluoride encapsulation

Selectivity within thecovalent capsule

Current Group members:Dr. Barun Jana (RA)Dr. SouravChakraborty(SRF)Bijit Chowdhury (SRF)Saikat Santra (SRF)Tamal Kanti Ghosh (SRF)Siddhartha Maji (JRF) Sanghamitra Sinha (JRF)Sourenjit Naskar (JRF)Somenath Bej (JRF)Mandira Nandi (JRF)Sayan Sarkar (JRF)Rajib Ghosh (JRF)Sahidul Mondal (JRF)

Alumni (PhD)Dr. P. S. LakshminarayananDr. I. RavikumarDr. M. ArunachalamDr. B. Nisar AhamedDr. Purnandhu BoseDr. Subrata SahaDr. Ranjan DuttaDr. Bidyut Akhuli

Financial Support……Swarnajaynti FellowshipSERB, DSTCSIRTata SteelIACS

Dr. S. MarivelDr. N. HaridharanDr. Snehadrinarayan KhatuaDr. Arnab MaityDr. Milan BeraDr. Sandip Mukherjee

Alumni (RA & Short term visitors)