Water-soluble BODIPY dyes: a novel approach for their sustainable chemistry and applied photonics.

The BODIPY family of organic dyes has emerged as a cornerstone in photonics research development, driving innovation and advancement in various fields of high socio-economic interest. However, the majority of BODIPY dyes exhibit hydrophobic characteristics, resulting in poor solubility in water and other hydrophilic solvents. This solubility is paramount for their optimal utilization in a myriad of photonic applications, particularly in the realms of biology and medicine.

Triplet-triplet sensitizing within pyrene-based COO-BODIPY: a breaking molecular platform for annihilating photon upconversion.

We envisioned a new approach for achieving triplet-triplet annihilation-assisted photon upconversion based on the rational design of a heavy-atom-free, all-organic and photoactivatable triplet-triplet synergistic multichromophoric molecular assembly. This single molecular architecture is easily built by covalently anchoring triplet-annihilator units (pyrenes) to a triplet-photosensitizer moiety (BODIPY), to improve the effectiveness and probability of the required triplet-triplet energy transfer and the ulterior triplet-triplet annihilation. This unprecedented design takes advantage of the high synthetic accessibility and chemical versatility of the -BODIPY scaffold.

BCl-Activated Synthesis of COO-BODIPY Laser Dyes: General Scope and High Yields under Mild Conditions.

A general and straightforward method for the synthesis of COO-BODIPYs from F-BODIPYs and carboxylic acids is established. The method is based on the use of boron trichloride to activate the involved substitution of fluorine, which leads to high yields through rapid reactions under soft conditions. This mild method opens the way to unprecedented laser dyes with outstanding efficiencies and photostabilities, which are difficult to obtain by the current methods.

N-BODIPYs Come into Play: Smart Dyes for Photonic Materials.

N-BODIPYs (diaminoboron dipyrromethenes) are unveiled as a new family of BODIPY dyes with huge technological potential. Synthetic access to these systems has been gained through a judicious design focused on stabilizing the involved diaminoboron chelate. Once stabilized, the obtained N-BODIPYs retain the effective photophysical behavior exhibited by other boron-substituted BODIPYs, such as O-BODIPYs.

Push-pull flexibly-bridged bis(haloBODIPYs): solvent and spacer switchable red emission.

A series of uncommon bis(BODIPYs), involving a flexible bridge linking the BODIPY α-positions and key functionalities to efficiently give an electronic push-pull effect, has been synthesized, as well as photophysically and structurally studied. It is demonstrated that the designed push-pull effect efficiently enables intramolecular charge transfer (ICT) processes upon photoexcitation, with the generated low-lying ICT state being the main deactivation channel from the locally excited state and, hence, ruling the fluorescence response. Noticeably, this response is modulated by the solvent polarity, and also by the bridge structure.

Bis(haloBODIPYs) with Labile Helicity: Valuable Simple Organic Molecules That Enable Circularly Polarized Luminescence.

Simple organic molecules (SOM) based on bis(haloBODIPY) are shown to enable circularly polarized luminescence (CPL), giving rise to a new structural design for technologically valuable CPL-SOMs. The established design comprises together synthetic accessibility, labile helicity, possibility of reversing the handedness of the circularly polarized emission, and reactive functional groups, making it unique and attractive as advantageous platform for the development of smart CPL-SOMs.