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Abstract Cross‐linked block copolymers are structurally complex, and utilization of traditional methods of molecular representation in chemoinformatics is only of limited applicability. Therefore, we introduced new techniques of structural representation for block copolymers. We developed additive and combinatorial approaches that treat a copolymer as a mixture system. In this approach, DRAGON descriptors are concentration‐weighted for all chemicals in the reaction mixture. As a proof of concept, we have studied glass transition temperatures of block copolymers of hydroxyalkyl‐ and dihydroxyalkyl carbamate terminated poly(dimethylsiloxane) oligomers with poly(‐caprolactone) and developed four quantitative structure‐property relationships (QSPR) models. The correlation coefficient (R²) for mentioned QSPR models ranges from 0.851 to 0.911 for the training set. In addition to the newly introduced technique we found that the octanol−water partition coefficient and 3D‐MoRSE unweighted descriptors were the most important descriptors for the studied property. The results of the study demonstrated that all chemicals in reaction mixture influenced the glass transition temperatures. 

Transition metal complexes are an ideal target system for the computational modeling of photoluminescence to further improve their applications as emitters. In addition to strongly absorbing visible light, their photoactivity is highly tunable due to a wide selection of ligands which can modify the nature of photoinduced charge transfer (CT) in the system. For photochemical purposes, a long-lived CT state is ideal. This is exemplified by ruthenium(II) tris(bipyridine), which achieves such a state by undergoing intersystem crossing (ISC) due to the large spin-orbit coupling (SOC) for the ruthenium metal center’s d-electrons.1 The mechanism by which the CT state’s long lifetime is achieved is through flipping the spin of the electron in the excited state, which makes for a spin-forbidden relaxation. Despite these strengths, ruthenium remains very cost-prohibitive due to its small natural abundance compared to other transition metals. For this reason, several analogs to copper(I) bis(phenanthroline) have been studied as systems that exhibit CT state lifetimes similar to those in ruthenium (II) tris(bipyridine).2 These analogs seek to improve the CT character of copper(I) bis(phenanthroline) by functionalization with electron withdrawing groups and by extending the ligands’ π-systems. This study employs density- functional theory (DFT) as a basis for the computation of photoinduced CT lifetimes and quantum yields by factoring in spin-polarization and SOC, while operating under the framework of Redfield theory.3 This treatment couples the system to a heat bath and moreover allows for the simulation of dynamics using a reduced density matrix. Redfield dynamics enables the simulation of CT state lifetimes with the inclusion of spin effects. Non-adiabatic couplings (NACs), calculated using an “on-the-fly” technique, are used to extract Redfield tensors which may then be used in the simulation of electronic relaxation over time. It is expected that both electron withdrawing groups and extensions to the ligands’ π-systems would increase the lifetime and quantum yield of photoluminescence. References: (1) (2) (3) Caspar, J. V.; Meyer, T. J. Photochemistry of Tris(2,2’-Bipyridine)Ruthenium(2+) Ion (Ru(Bpy)32+). Solvent Effects. J. Am. Chem. Soc. 1983, 105 (17), 5583–5590. https://doi.org/10.1021/ja00355a009. Lavie-Cambot, A.; Cantuel, M.; Leydet, Y.; Jonusauskas, G.; Bassani, D. M.; McClenaghan, N. D. Improving the Photophysical Properties of Copper(I) Bis(Phenanthroline) Complexes. Coordination Chemistry Reviews 2008, 252 (23–24), 2572–2584. https://doi.org/10.1016/j.ccr.2008.03.013. Redfield, A. G. The Theory of Relaxation Processes. In Advances in Magnetic and Optical Resonance; Elsevier, 1965; Vol. 1, pp 1–32. https://doi.org/10.1016/B978-1-4832-3114-3.50007-6. 

The synthesis, photophysics, and electrochemiluminescence (ECL) of four water-soluble dinuclear Ir( iii ) and Ru( ii ) complexes (1–4) terminally-capped by 4′-phenyl-2,2′:6′,2′′-terpyridine (tpy) or 1,3-di(pyrid-2-yl)-4,6-dimethylbenzene (N^C^N) ligands and linked by a 2,7-bis(2,2′:6′,2′′-terpyridyl)fluorene with oligoether chains on C9 are reported. The impact of the tpy or N^C^N ligands and metal centers on the photophysical properties of 1–4 was assessed by spectroscopic methods including UV-vis absorption, emission, and transient absorption, and by time-dependent density functional theory (TDDFT) calculations. These complexes exhibited distinct singlet and triplet excited-state properties upon variation of the terminal-capping terdentate ligands and the metal centers. The ECL properties of complexes 1–3 with better water solubility were investigated in neutral phosphate buffer solutions (PBS) by adding tripropylamine (TPA) as a co-reactant, and the observed ECL intensity followed the descending order of 3 > 1 > 2. Complex 3 bearing the [Ru(tpy) 2 ] 2+ units displayed more pronounced ECL signals, giving its analogues great potential for further ECL study. 

Two heteroleptic monocationic Ir( iii ) complexes bearing 6,6′-bis(7-benzothiazolylfluoren-2-yl)-2,2′-biquinoline as the diimine ligand with different degrees of π-conjugation were synthesized and their photophysics was investigated by spectroscopic techniques and first principles calculations. These complexes possessed two intense absorption bands at 300–380 nm and 380–520 nm in toluene that are predominantly ascribed to the diimine ligand-localized 1 π,π* transition and intraligand charge transfer ( 1 ILCT)/ 1 π,π* transitions, respectively, with the latter being mixed with minor 1 MLCT (metal-to-ligand charge transfer)/ 1 LLCT (ligand-to-ligand charge transfer) configurations. Both complexes also exhibited a spin-forbidden, very weak 3 MLCT/ 3 LLCT/ 3 π,π* absorption band at 520–650 nm. The emission of these complexes appeared in the red spectral region ( λ em : 640 nm for Ir-1 and 648 nm for Ir-2 in toluene) with a quantum yield of <10% and a lifetime of hundreds of ns, which emanated from the 3 ILCT/ 3 π,π* state. The 3 ILCT/ 3 π,π* state also gave rise to broad and moderately strong transient absorption (TA) at ca. 480–800 nm. Extending the π-conjugation of the diimine ligand via inserting CC triplet bonds between the 7-benzothiazolylfluoren-2-yl substituents and 2,2′-biquinoline slightly red-shifted the absorption bands, the emission bands, and the TA bands in Ir-2 compared to those in Ir-1 that lacks the connecting CC triplet bonds in the diimine ligand. The stronger excited-state absorption with respect to the ground-state absorption at 532 nm led to strong reverse saturable absorption (RSA) for ns laser pulses at this wavelength, with the RSA of Ir-2 being slightly stronger than that of Ir-1, which correlated well with their ratios of the excited-state to ground-state absorption cross sections ( σ ex / σ 0 ). These results suggest that extending the π-conjugation of the 2,2′-biquinoline ligand via incorporating the 7-benzothiazolylfluoren-2-yl substituents retained the broad but weak ground-state absorption at 500–650 nm, meanwhile increased the triplet excited-state lifetimes, which resulted in the much stronger triplet excited-state absorption in this spectral region and strong RSA at 532 nm. Thus, these complexes are promising candidates as broadband reverse saturable absorbers.