Table 1.

Summary of features in representative compounds.

Compound	Spectral Properties	Application	Reference
1	Excitation wavelength: 648 nm; emission: 750 nm.	Rapid monitoring of minor pH fluctuations and live cell imaging (HepG2 and HL-7702)	2
2	Stokes shift of 140 nm	Multichannel imaging	3
3	Absorption maxima: 690 nm (neutral pH), 605 nm (acid pH); excitation maxima: 605 nm; emission maxima: 690 nm.	pH monitoring	8
4	Absorption maxima in MeOH, 645 nm (ε = 50800 M−1cm−1); Absorption maxima in acidified MeOH (pH < 2), 914 nm (ε= 142000 M−1cm−1)	pH monitoring	11
5	Absorption maxima for the chlorin component of the dyad: 650 nm (ε= 60000 M−1cm−1); emission maxima: 760 nm. Large Stokes shift (110 nm). Solvent: toluene.	Potential application in NIR imaging upon further modifications to create water-soluble bioconjugatable chlorin-bacteriochlorin (B–C) dyads.	16
6	Absorption maximas: 475, 591. 835, 947 and 1087 nm (free base), 638, 809, 888 and 1016 nm (protonated form); excitation maxima: 600 nm; emission maxima: 1094 nm (free base), 1044 nm (protonated). Solvent: CH2Cl2.	No specific application is mentioned.	22
7	Absorption maxima: 717 nm (ε= 104400 M−1cm−1); emission maxima: 774 nm. Solvent: CHCl3.	Affinity for copper	34
8	Absorption maxima: 723 nm (ε= 253000 M−1cm−1); emission maxima: 738 nm. Solvent: CHCl3.	High-resolution multicolor bioanalysis and bioimaging.	35, 36
9	In the isothianaphthene family, for the compound with R=N(Me)2 the absorption maxima is 579 nm and the emission maxima is 785 nm. Stokes shift = 206 nm	Under testing as NIR contrast agents for biomedical applications.	42
10	Absorption maxima: 536 nm; emission maxima: 733 nm. Stokes shift: 197 nm. Solvent: Aqueous phosphate buffer with 1% DMSO.	Live cell imaging	45