1

Supporting Information

“Turn-On” fluorescent chemosensor for Zinc (II) dipodal ratiometric receptor: Application in live cell imaging.

Kundan Tayade a,b, Banashree Bondhopadhyayd Hemant Sharmac, Anupam Basud, Vikas Gitea, Sanjay Attardeb, Narinder Singh*c, Anil Kuwar*a aSchool of Chemical Sciences, North Maharashtra University, Jalgaon 425 001 (MS) India.bSchool of Environmental and Earth Sciences, North Maharashtra University, Jalgaon 425 001 (MS) India.cDepartment of Chemistry, Indian Institute of Technology, Ropar, Rupanagar (Punjab) India.dMolecular Biology and Human Genetics Laboratory, Department of Zoology, The University of Burdwan, Burdwan, West Bengal, India. ----------------------------------------------------------------------------------------------------------

* Corresponding authors. Tel.: +91-257-2257432; fax: +91-257-2257403

E-mail addresses: kuwaras@gmail.com nsingh@iitrpr.ac.in

Electronic Supplementary Material (ESI) for Photochemical & Photobiological Sciences.This journal is © The Royal Society of Chemistry and Owner Societies 2014

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4000.0 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 451.07.9

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22

24

26

28

30

32

34

36

38

40

42

44

46

48

50

52

53.9

cm-1

%T 3290.66

3172.66

2924.61

2854.83

1592.06

1533.54

1499.62

1365.001309.63

1247.94

1228.89

771.36750.26

692.35

Figure S1. IR spectra of receptor 2

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Figure S2. 1H-NMR spectra of receptor 2

Figure S3. 13C-NMR spectra of receptor 2

Figure S4. LC-MS spectra of receptor 2 (M+H+)

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Figure S5a. TGA of receptor 2 (heating rate 10 per minute under nitrogen ℃

environment).

Figure S5b. TGA of receptor 2.Zn2+ (heating rate 10 per minute under nitrogen ℃environment).

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Figure S6a. DSC of receptor 2.

Figure S6b. DSC of receptor 2.Zn2+.

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Figure S7a. Fluorescence titration spectra of receptor 2 (0.1 mM) in the presence of

different concentrations of Zn2+ (1 mM) (λex = 278 nm, λem = 341 nm, excitation and

emission slit 5 nm) up to 10 µl (0.05 equiv.).

Figure S7b. Fluorescence titration spectra of receptor 2 (0.1 mM) in the presence of different concentrations of Zn2+ (1 mM) (λex = 278 nm, λem = 341 nm, excitation and emission slit 5 nm) up to 400 µL (2 equiv.).

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0 0.200000003

0.400000006

0.600000009

0.800000012

1.000000015

1.200000018

1.400000021

1.600000024

0.00E+001.00E+07

2.00E+07

Equivalent of Zn2+ ion added

Inte

nsity

(cps

)

Figure S7c. Mole ratio plot (λem = 341 nm) illustrating the changing stoichiometry from 2:1 to 1:1.

Zn(II)N

a(I)

K(I)

Mg(II)

Al(III)

Cs(I)Ba(II)Ca(II)Sr(II)Cr(III)M

n(II)Fe(III)Co(II)N

i(II)Cu(II)Cd(II)H

g(II)Pb(II)Th(IV

)A

g(I)Bi(III)U

(VI)

-2-1

01

23

45

Various Metal Ions

ΔF/F

0

Figure S8. Fluorescence spectrometric response (ΔF = F−F0) of receptor 2 (0.1 mM) upon addition of 100 µL of respective cation salts (1 mM) in CH3CN/H2O.

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Zn(II)N

a(I)K

(I)M

g(II)A

l(III)Cs(I)Ba(II)Ca(II)Sr(II)Cr(III)M

n(II)Fe(III)Co(II)N

i(II)Cu(II)Cd(II)H

g(II)Pb(II)Th(IV

)A

g(I)Bi(III)U

(VI)

0.00E+001.00E+07

2.00E+07

Competating Ions Competating Ions + Zn(II)

Various Metal Ions

Inte

nsity

(cps

)

Figure S9. A fluorescence sensing of Zn2+ ion (1 mM, 1equiv) by receptor 2 (0.1 mM) in the presence of other competing cations (1mM, 2 equiv.).

Figure S10a. Job’s plot representing the stoichiometry of complex 2.Zn2+ (host : guest;

1:1).

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-5 -4.5

-4 -3.5

-3 -2.5

-2 -1.5

-1 -0.5

0

00.2

0.40.6

0.81

1.2

LOG[G]

(F0-

F)/(F

0-Fm

ax)

Figure S10b. Normalized plot obtained from fluorescence spectroscopy (λem = 341 nm).

-5 -4.5

-4 -3.5

-3 -2.5

-2 -1.5

-1 -0.5

0

00.2

0.40.6

0.81

1.21.4

LOG[G]

LO

G[(

F - F

0)/(F

∞ -

F)

Figure S10c. Fluorescence intensity at 341nm of receptor 2 (0.1 mM) versus increasing concentration of Log[Zn2+]. The fluorescence response fits to a Hill coefficient of 1.1446, which is in concordance with the 1:1 binding stoichiometry for the receptor 2.Zn2+ complex.

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Figure S11. LC-MS spectra of 2.Zn2+ complex (M+H+)

0 20000

40000

60000

80000

100000

120000

05E-8

0.0000001

1/[G]

1/∆F

Figure S12a. A Benesi-Hildebrand methodology for receptor 2, (1/∆F) vs 1/[G], Ka = 1.29 × 106 M-1.

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0.00E+00

2.00E+06

4.00E+06

6.00E+06

8.00E+06

1.00E+07

1.20E+07

05E+11

1E+121.5E+12

∆F

∆F/[G

]

Figure S12b. A Scatchard methodology for receptor 2, ∆F/[G] vs ∆F, Ka = 1.00 × 106

M-1.

0 1 2 3 4 5 6 7 8

-1000000-500000

0

F/F0

(1-F

/F0)

/[G]

Figure S12c. Connor’s fitting method for receptor 2, (1-F/F0)/[G] vs F/F0, Ka = 1.94 × 106 M-1

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Figure S13. 1H-NMR spectra (A) only receptor 2 (B) complex 3.

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Figure S14: Change in fluorescence intensity of receptor 2 at 341 nm upon varying the pH of the solution.

Figure S15: Change in fluorescence intensity of receptor 2 at 341 nm at various temperature.

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Figure S16: Fluorescence intensity of receptor 2 at 341 nm upon addition of Zn2+ ion (1 mM) over time.

Table S1: Comparison of literature reports with present work.

References Detection Limit Solvent

Zhou et. al., (2012) 2.2×10-7 M CH3CN-H2O

Dong et. al.,(2014) 1×10-7 M CH3CN-Tris-HCl

Li et. al., (2014) 4.9×10-8 M CH3CN-H2O

Kaur et. al., (2014) 1×10-6 M DMF-H2O

Sivaraman et. al., (2012) 1.5×10-7 M Phosphate buffer

Present work 6.5×10-7 M CH3CN-H2O

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Table S2: An optimized bond angles, dihedral angles, bond length and energy

calculated at B3LYP/ LANL2DZ level.

Parameter Receptor 2 3

Dihedral angles (°)N25-C29-C30-N26 61.09 55.65 C29-C30-N26-C24 ` -135.57 -158.35 C5-C4-C23-N25 33.34 115.51 O21-C3-C4-C23 -0.50 6.07 C27-C23-N25-C29 -66.67 -63.07 C3-C4-C23-N25 -147.43 -68.10 O22-C12-C11-C24 -2.34 6.08 C11-C24-N26-C30 157.50 169.33 Bond angles (°)C23-N25-C29 116.22 113.26 C5-C4-C23 121.38 123.03 C30-N26-C24 120.29 113.26 N26-C24-C28 113.49 110.98 N25-C29-C30 109.24 111.36 Bond Length (Å)N25-C29 1.46 1.52 C30-N26 1.46 1.52 C24-N26 1.47 1.54 C23-N25 1.47 1.54 C12-O22 1.39 1.46 C3-O21 1.40 1.46 O22-H45 0.97 0.97 O21-H44 0.97 0.97 N25-H42 1.01 1.02 N26-H43 1.01 1.02 C23-C27 1.54 1.53 Energy (a.u.) -960.28 -1025.33