Table 1 Photophysical properties of newly synthesized MARS model compounds.

From: 9-Cyanopyronin probe palette for super-multiplexed vibrational imaging

MARS

Nitrile

Core

Number of ring expansions

Measured Raman shift (cm−1)a

Predicted Raman shift (cm−1)

λabs (nm)b

RIEc

1

C≡N

O

0

2241

2241

670

75

2

1

2240

2240

675

86

3

2

2239

2239

680

93

4

3

2238

2238

690

108

5

4

2237

2237

700

120

6a

C≡N

O

3

2238

2238

690

111

6b

C≡15N

3

2210

2210

6c

13C≡N

3

2184

2184

6d

13C≡15N

3

2155

2156

7a

C≡N

C

3

2228

2230

760

435

7b

C≡15N

3

2200

2202

7c

13C≡N

3

2176

2176

7d

13C≡15N

3

2147

2148

8a

C≡N

Si

3

2222

2222

790

940

8b

C≡15N

3

2195

2194

8c

13C≡N

3

2171

2168

8d

13C≡15N

3

2141

2140

  1. a, bMeasured in DMSO solution. See supplementary information for spectroscopic data measured in PBS buffer.
  2. cRIE: relative intensity v.s. EdU (5-ethynyl-2’-deoxyuridine) with the same SRS acquisition parameters.