Supporting Information

A simple Schiff-base fluorescence probe for the simultaneous detection of Ga3+ and Zn2+

Seong Youl Lee, Kwon Hee Bok, Tae Geun Jo, So Young Kim, Cheal Kim*

Department of Fine Chemistry and Department of Interdisciplinary Bio IT Materials, Seoul

National University of Science and Technology, Seoul 139-743, Korea. Fax: +82-2-973-

9149; Tel: +82-2-970-6693; E-mail: chealkim@seoultech.ac.kr

1

Table S1. Examples of various Ga3+ chemosensors.

Sensor Detection limit (µM) Binding constant Interference Solvent Method of detection Reference

2.37 3.82 x 104 None ethanol : water = 98 : 2 Fluorescence 1

No data 6.25 x 104 Cu2+ acetonitrile Fluorescence 2

0.54 8.08 x 108 Cd2+, Ni2+, Cu2+ water Fluorescence 3

0.05 1.21 x 105 Co2+, Cu2+, Fe3+ ethanol Fluorescence 4

0.1 2.5 x 106 No data methanol Fluorescence 5

2.4 1.0 x 105 Cu2+ metanol Fluorescence 6

0.01 1.0 x 104 Cu2+, Fe2+, Fe3+ acetonitrile Fluorescence This work

OH

OH

NH

S

CO2H

OH

N

S

N

N NN

OHHO

N

N

NCH

HO OH

NHC

OH

OH

HO

N

N OH

N

N

OH

HN N

O

O

HO

References

1 Wang, Y.-W.; Liu, S.-B.; Ling, W.-J.; Peng,Y. Chem. Commun., 2016, 52, 827-830.

2 Kim, B.-Y.; Kim, H.-S.; Helal, A. Sens. Actuators B, 2015, 206, 430-434.

3 Tavallali, H. P.; Vahdati; Shaabanpur, E. Sens. Actuators B, 2011, 159, 154-158.

4 Kimura, J.; Yamada, H.; Ogura, H.; Yajima, T.; Fukushima, T. Anal. Chim. Acta,

2

2009, 635, 207-213.

5 Noh, J. Y.; Kim, S.; Hwang, I. H.; Lee, G. Y.; Kang, J.; Kim, S. H.; Min, J.; Park, S.;

Kim, C.; Kim, J. H. Dyes Pigm., 2013, 99, 1016-1021.

6 Kim, H.; Kim, K. B.; Song, E. J.; Hwang, I. H.; Noh, J. Y.; Kim, P. G.; Jeong, K. D.;

Kim, C. Inorg. Chem. Commun., 2013, 36, 72-76.

3

Fig S1 1H NMR spectrum of 1

4

Fig. S2 13C NMR spectrum of 1

5

Fig. S3 Job plot of 1 and Ga3+. The total concentrations of 1 and Ga3+ were 100 μM

(excitation: 300 nm).

6

Fig. S4 Benesi-Hildebrand plot (at 434 nm) of 1 based on fluorescence titration, assuming 1:1

stoichiometry for association between 1 and Ga3+.

7

Fig. S5 Determination of the detection limit based on change in the ratio of 1 (10 μM) with

Ga3+.

8

0

100

200

300

400

500

1Ga3+

Cr3+

Int.

at 4

34 n

m (a

.u.)

1Ga3+

Fe2+

1Ga3+

Co2+

1Ga3+

Ag+

1Ga3+

Al3+

1 1Ga3+

Ca2+

1Ga3+

Hg2+

1Ga3+

Cu2+

1Ga3+

Cd2+

1Ga3+

In3+

1Ga3+

Mn2+

1Ga3+

Pb2+

1Ga3+

Na+

1Ga3+

Zn2+

1Ga3+

Ni2+

1Ga3+

Mg2+

1Ga3+

K+

1Ga3+

Fe3+

1 1Ga3+

Fig. S6 Competitive selectivity of 1 (10 μM) toward Ga3+ (3.0 equiv) in the presence of other

metal ions (3.0 equiv, excitation: 300 nm).

9

0.0 0.2 0.4 0.6 0.8 1.00

100

200

Int.

at 4

60 n

m (a

.u.)

[Zn2+]/([1] + [Zn2+])

Fig. S7 Job plot of 1 and Zn2+. The total concentrations of 1 and Zn2+ were 100 μM

(excitation: 300 nm).

10

Fig. S8 Positive-ion electrospray ionization mass spectrum of 1 (10 μM) upon addition of

Zn(NO3)2 (1.0 equiv).

11

Fig. S9 1H NMR titration of 1 with Zn2+ ions.

12

Fig. S10 Benesi-Hildebrand plot (at 460 nm) of 1 based on fluorescence titration, assuming

1:1 stoichiometry for association between 1 and Zn2+.

13

4 6 8 10 12

120

160

200

240

In

t. at

460

nm

(a.u

.)

[Zn2+]/

Fig. S11 Determination of the detection limit based on change in the ratio of 1 (10 μM) with

Zn2+.

14

0

100

200

300

Int.

at 4

60 n

m (a

.u.)

1Zn2+

Cr3+

1Zn2+

Fe2+

1Zn2+

Co2+

1Zn2+

Ag+

1Zn2+

Al3+

1 1Zn2+

Ca2+

1Zn2+

Hg2+

1Zn2+

Cu2+

1Zn2+

Cd2+

1Zn2+

In3+

1Zn2+

Mn2+

1Zn2+

Pb2+

1Zn2+

Na+

1Zn2+

Ga3+

1Zn2+

Ni2+

1Zn2+

Mg2+

1Zn2+

K+

1Zn2+

Fe3+

1 1Zn2+

Fig. S12 Competitive selectivity of 1 (10 μM) toward Zn2+ (3.6 equiv) in the presence of

other metal ions (3.6 equiv, excitation: 300 nm).

15

(a)

(b)

Fig. S13 (a) The theoretical excitation energies and the experimental UV-vis spectrum of 1.

(b) The major electronic transition energies and molecular orbital contributions for 1 (H =

HOMO and L = LUMO).

16

(a)

(b)

Fig. S14 (a) The theoretical excitation energies and the experimental UV-vis spectrum of 1-

Ga3+. (b) The major electronic transition energies and molecular orbital contributions for 1-

Ga3+ (H = HOMO and L = LUMO).

17

Fig. S15 Molecular orbital diagrams and excitation energies of 1 and 1-Ga3+ complex.

(a)18

(b)

Fig. S16 (a) The theoretical excitation energies and the experimental UV-vis spectrum of 1-

Zn2+. (b) The major electronic transition energies and molecular orbital contributions for 1-

Zn2+ (H = HOMO and L = LUMO).

19

Fig. S17 Molecular orbital diagrams and excitation energies of 1 and 1-Zn2+ complex.

20