Conspectus In 1960, Weber prophesied that “There are many ways in which the properties
of the excited state can be utilized to study points of ignorance of the structure and function …

Various molecules which are similar to the natural nucleobases exist in nature or have been
synthetically developed. In this chapter we review work on the photophysical properties of …

An enzymatic method has been successfully established enabling the generation of partially
base-modified RNA (previously named RZA) constructs, in which all G residues were …

A series of emissive ribonucleoside purine mimics, all comprised of an isothiazolo [4, 3-d]
pyrimidine core, was prepared using a divergent pathway involving a key Thorpe–Ziegler …

Thienoguanosine (thG) is an isomorphic nucleoside analogue acting as a faithful fluorescent
substitute of G, with respectable quantum yield in oligonucleotides. Photophysical analysis …

An enzyme‐mediated approach for the assembly of singly modified RNA constructs in which
specific G residues are replaced with thG, an emissive isomorphic G surrogate, is reported …

This study presents a comprehensive theoretical exploration of the fluorescent non-natural
emissive nucleobases-mthA, mthG, mthC, and mthU derived from the methylthieno [3, 4-d] …

A series of enzymatic transformations, which generate visibly emissive isofunctional
cofactors based on an isothiazolo [4, 3‐d] pyrimidine analogue of adenosine (tzA), was …

We employ density functional theory (DFT) and time-dependent DFT (TDDFT) calculations to
investigate the structural, energetic and optical properties of a new computationally …

We present theoretical characterization of fluorescent non-natural nucleobases, tzA, tzG,
tzC, and tzU, derived from the isothiazolo [4, 3-d] pyrimidine heterocycle. Consistent with the …