Chapter 1 Introduce of triplet excited state in DNA and RNA
1.1 Introduction of the significance of triplet excited state in nucleic acids
1.2 Triplet excited state studies in 1960-70s with low temperature spectroscopy
1.3 Breakthroughs of time-resolved spectroscopy techniques and progress of triplet excited state study of DNA/RNA in 1980-2000
1.4 Current Research frontiers (2000s-present)
1.5 Book Structure Overview

Chapter 2 Triplet excited state in canonical nucleobases and their derivatives
2.1 Study on the triplet excited states dynamics of canonical nucleobases by laser flash photolysis and femtosecond transient absorption spectroscopy
2.2 Study on Triplet Excited-State Dynamics of Thio- and Selenium-Substituted Nucleobases
2.3 Study on Triplet Excited State Dynamics of Nitrogen-substituted Nucleobases

Chapter 3 Decoding Triplet-State Dynamics in Epigenetically Modified DNA and RNA: Photophysical Mechanisms from Nucleobase Monomers to Duplex
3.1 Introduction
3.2 Formation of Triplet State in Epigenetically Modified Nucleobase Monomer
3.3 Uracil C5-modified Nucleobases
3.4 Adenine N6-Modified Nucleobases
3.5 Guanosine N7-Modified Nucleobases
3.6 Formation of Triplet State in Epigenetically Modified Dinucleotides and Single-stranded Oligomers
3.7 Formation of Triplet State in Epigenetically Modified DNA duplex
3.8 Conclusion

Chapter 4 Triplet-Mediated Photochemistry of Nucleic Acid Bases
4.1 Introduction
4.2 Photoaddition reactions
4.3 Photooxidation reactions
4.4 Photo-crosslinking reactions
4.5 Conclusions

Chapter 5 Drug-sensitized triplet states generation in DNA
5.1 Introduction
5.2 The triplet-triplet energy transfer process
5.3 The triplet energy of nucleobases
5.4 Structure and triplet excited state energies of the different nucleobases
5.5 Photoproducts arising from the nucleobase triplet excited state
5.6 Methodologies: Spectroscopic vs analytical techniques for detection of drug photosensitization of 3N*
5.7 Photosensitization of nucleobase triplet by drugs (or cosmetics)
5.8 Conclusion

Chapter 6 Triplet decay in canonical and noncanonical DNA/RNA nucleobases
6.1 Introduction
6.2 Low Triplet Yields in Natural DNA/RNA Nucleobases
6.3 Triplet State Decay in Thionucleobases
6.4 Theoretical and Computational Studies of Triplet Decay of Thionucleobases
6.5 Mechanisms of Chemical Modulation of Triplet Decay
6.6 Remaining Challenges and Future Directions

Chapter 7 Triplet state dynamics in DNA/RNA nucleobases and DNA by Ab initio static and surface-hopping dynamics simulations
7.1 Introduction
7.2 Adenine
7.3 Guanine
7.4 Uracil
7.5 Thymine
7.6 Cytosine
7.7 Non-natural nucleobases
7.8 Pyrimidine-pyrimidine dimer formation processes
7.9 Conclusions

Chapter 8 The photophysics and photochemistry of epigenetics and 'natural' non canonical bases: insights from quantum mechanical calculations.
8.1 Introduction
8.2 Epigenetic bases
8.3 Methylated purines
8.4 Concluding Remarks