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1. meso-Aryl substituents modify the electrochemical profile and palladium(II) coordination of redox-active tripyrrin ligands

   https://doi.org/10.1039/D3QI02597G  

   Habenšus, Iva; Tomat, Elisa (March 2024, Inorganic Chemistry Frontiers)

   The synthesis of meso-aryl 1,14-dimethoxytripyrrin and tripyrrin-1,14-dione allows isolation of palladium(II) complexes presenting aliphatic C–H bond activation reactivity and multiple ligand-based redox processes. 

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2. Mono ‐ and Bis ‐Alkylated Lumazine Sensitizers: Synthetic, Molecular Orbital Theory, Nucleophilic Index and Photochemical Studies

   https://doi.org/10.1111/php.13310  

   Sosa, María José; Urrutia, María Noel; Schilardi, Patricia L.; Quindt, Matías I.; Bonesi, Sergio M.; Denburg, Dobrushe; Vignoni, Mariana; Greer, Alexander; Greer, Edyta M.; Thomas, Andrés H. (August 2020, Photochemistry and Photobiology)

   Abstract Mono‐ andbis‐decylated lumazines have been synthesized and characterized. Namely,mono‐decyl chain [1‐decylpteridine‐2,4(1,3H)‐dione]6aandbis‐decyl chain [1,3‐didecylpteridine‐2,4(1,3H)‐dione]7aconjugates were synthesized by nucleophilic substitution (S_N2) reactions of lumazine with 1‐iododecane inN,N‐dimethylformamide (DMF) solvent. Decyl chain coupling occurred at theN¹site and then theN³site in a sequential manner, without DMF condensation. Molecular orbital (MO) calculations show ap‐orbital atN¹but notN³, which along with a nucleophilicity parameter (N) analysis predict alkylation atN¹in lumazine. Only after the alkylation atN¹in6a, does ap‐orbital onN³emerge thereby reacting with a second equivalent of 1‐iododecane to reach the dialkylated product7a. Data from NMR (¹H,¹³C, HSQC, HMBC), HPLC, TLC, UV‐vis, fluorescence and density functional theory (DFT) provide evidence for the existence ofmono‐decyl chain6aandbis‐decyl chain7a. These results differ to pterinO‐alkylations (kinetic control), whereN‐alkylation of lumazine is preferred and then to dialkylation (thermodynamic control), with an avoidance of DMF solvent condensation. These findings add to the list of alkylation strategies for increasing sensitizer lipophilicity for use in photodynamic therapy. 

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3. Building Blocks and COFs Formed in Concert —Three‐Component Synthesis of Pyrene‐Fused Azaacene Covalent Organic Framework in the Bulk and as Films

   https://doi.org/10.1002/anie.202302872  

   Frey, Laura; Oliveira, Orlando; Sharma, Ashish; Guntermann, Roman; Fernandes, Soraia_P_S; Cid‐Seara, Krystal_M; Abbay, Hosanna; Thornes, Henry; Rocha, João; Döblinger, Markus; et al (June 2023, Angewandte Chemie International Edition)

   Abstract A three‐component synthesis methodology is described for the formation of covalent organic frameworks (COFs) containing extended aromatics. Notably, this approach enables synthesis of the building blocks and COF along parallel reaction landscapes, on a similar timeframe. The use of fragmental building block components, namely pyrene dione diboronic acid as aggregation‐inducing COF precursor and the diamineso‐phenylenediamine (Ph), 2,3‐diaminonaphthalene (Naph), or (1R,2R)‐(+)‐1,2‐diphenylethylenediamine (2Ph) as extending functionalization units in conjunction with 2,3,6,7,10,11‐hexahydroxytriphenylene, resulted in the formation of the corresponding pyrene‐fused azaacene, i.e., Aza‐COF series with full conversion of the dione moiety, long‐range order, and high surface area. In addition, the novel three‐component synthesis was successfully applied to produce highly crystalline, oriented thin films of the Aza‐COFs with nanostructured surfaces on various substrates. The Aza‐COFs exhibit light absorption maxima in the blue spectral region, and each Aza‐COF presents a distinct photoluminescence profile. Transient absorption measurements of Aza‐Ph‐ and Aza‐Naph‐COFs suggest ultrafast relaxation dynamics of excited‐states within these COFs. 

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4. Crystallographic, spectroscopic, and computational characterization of a diiodonaphthoquinone diarylethene photochrome: halogen bonding and photocrystallography

   https://doi.org/10.1039/D4CE00112E  

   Myers, Shea D; Marr, Zoe Y; Sency, Jade A; Mitchell, Travis B; Benedict, Jason B; Patel, Dinesh G (May 2024, CrystEngComm)

   We report the synthesis and characterization of 2,3-bis(5-iodo-2-methylthiophen-3-yl)naphthalene-1,4-dione and its ring-closed isomer. 

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5. Synthesis and Investigations of the Antitumor Effects of First-Row Transition Metal(II) Complexes Supported by Two Fluorinated and Non-Fluorinated β-Diketonates

   https://doi.org/10.3390/ijms25042038  

   Pellei, Maura; Del_Gobbo, Jo’; Caviglia, Miriam; Gandin, Valentina; Marzano, Cristina; Karade, Deepika V; Noonikara_Poyil, Anurag; Dias, H_V Rasika; Santini, Carlo (February 2024, International Journal of Molecular Sciences)

   The 3d transition metal (Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)) complexes, supported by anions of sterically demanding β-diketones, 1,3-dimesitylpropane-1,3-dione (HLMes) and 1,3-bis(3,5-bis(trifluoromethyl)phenyl)-3-hydroxyprop-2-en-1-one (HLCF3), were synthesized and evaluated for their antitumor activity. To assess the biological effects of substituents on phenyl moieties, we also synthesized and investigated the analogous metal(II) complexes of the anion of the less bulky 1,3-diphenylpropane-1,3-dione (HLPh) ligand. The compounds [Cu(LCF3)2], [Cu(LMes)2] and ([Zn(LMes)2]) were characterized by X-ray crystallography. The [Cu(LCF3)2] crystallizes with an apical molecule of solvent (THF) and features a rare square pyramidal geometry at the Cu(II) center. The copper(II) and zinc(II) complexes of diketonate ligands, derived from the deprotonated 1,3-dimesitylpropane-1,3-dione (HLMes), adopt a square planar or a tetrahedral geometry at the metal, respectively. We evaluated the antitumor properties of the newly synthesized (Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)) complexes against a series of human tumor cell lines derived from different solid tumors. Except for iron derivatives, cellular studies revealed noteworthy antitumor properties, even towards cancer cells endowed with poor sensitivity to the reference drug cisplatin. 

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